A Personalized QoS Prediction Approach for CPS Service Recommendation Based on Reputation and Location-Aware Collaborative Filtering

PubMed Central

Huang, Lan; Wang, Yin; Ma, Pengju; Li, Chuanbin; Zhu, Yujia

2018-01-01

With the rapid development of cyber-physical systems (CPS), building cyber-physical systems with high quality of service (QoS) has become an urgent requirement in both academia and industry. During the procedure of building Cyber-physical systems, it has been found that a large number of functionally equivalent services exist, so it becomes an urgent task to recommend suitable services from the large number of services available in CPS. However, since it is time-consuming, and even impractical, for a single user to invoke all of the services in CPS to experience their QoS, a robust QoS prediction method is needed to predict unknown QoS values. A commonly used method in QoS prediction is collaborative filtering, however, it is hard to deal with the data sparsity and cold start problem, and meanwhile most of the existing methods ignore the data credibility issue. Thence, in order to solve both of these challenging problems, in this paper, we design a framework of QoS prediction for CPS services, and propose a personalized QoS prediction approach based on reputation and location-aware collaborative filtering. Our approach first calculates the reputation of users by using the Dirichlet probability distribution, so as to identify untrusted users and process their unreliable data, and then it digs out the geographic neighborhood in three levels to improve the similarity calculation of users and services. Finally, the data from geographical neighbors of users and services are fused to predict the unknown QoS values. The experiments using real datasets show that our proposed approach outperforms other existing methods in terms of accuracy, efficiency, and robustness. PMID:29757995

Quality of service management framework for dynamic chaining of geographic information services

NASA Astrophysics Data System (ADS)

Onchaga, Richard

2006-06-01

Dynamic chaining of geographic information services (geo-services) is gaining popularity as a new paradigm for evolving flexible geo-information systems and for providing on-demand access to geo-information. In dynamic chaining, disparate geo-services are discovered and composed at run time to yield more elaborate functionality and create value-added geo-information. Common approaches to service chaining discover and compose disparate geo-services based on the functional capability of individual geo-services. The primary concern of common approaches is thus the emergent behavior of the resulting composite geo-service. However, as geo-services become mundane and take on a greater and more strategic role in mission critical processes, deliverable quality of service (QoS) becomes an important concern. QoS concerns operational characteristics of a service that determine its utility in an application context. To address pertinent QoS requirements, a new approach to service chaining becomes necessary. In this paper we propose a QoS-aware chaining approach in which geo-services are discovered, composed and executed considering both functional and QoS requirements. We prescribe a QoS management framework that defines fundamental principles, concepts and mechanisms which can be applied to evolve an effective distributed computing platform for QoS-aware chaining of geo-services - the so-called geo-service infrastructure. The paper also defines an extensible QoS model for services delivered by dynamic compositions of geo-services. The process of orthophoto generation is used to demonstrate the applicability of the prescribed framework to service-oriented geographic information processing.

Differentiated optical services: a quality of optical service model for WDM networks

NASA Astrophysics Data System (ADS)

Ndousse, Thomas D.; Golmie, Nada

1999-08-01

This paper addresses the issues of guaranteed and scalable end-to-end QoS in Metropolitan DWDM networks serving as transit networks for IP access networks. DWDM offering few wavelengths have in the past been deployed in backbone networks to upgrade point-to-point transmission where sharing is based on coarse granularity. This type of DWDM backbone networks, offering few lightpaths, provides no support for QoS services traversing the network. As DWDM networks with larger numbers of wavelengths penetrate the data-centric Metro environment, specific IP service requirements such as priority restoration, scalability, dynamic provisioning of capacity and routes, and support for coarse-grain QoS capabilities will have to be addressed in the optical domain in order to support end-to-end Service- Level Agreements. In this paper, we focus on the support of QoS in the optical domain in order to achieve end-to-end QoS over a DWDM network. We propose a QoS service model in the optical domain called Differentiated Optical Services (DOS). Service classification in DOS is based on a set of optical parameters that captures the quality and reliability of the optical lightpath.

How to measure the QoS of a web-based EHRs system: development of an instrument.

PubMed

de la Torre-Díez, Isabel; López-Coronado, Miguel; Rodrigues, Joel J P C

2012-12-01

The quality of service (QoS) can be treated as a set of concepts whose satisfaction/dissatisfaction generates a global positive/negative vision about the service provided by any application. The different nature of the services and its features require an analysis of the factors that have the greatest influence on the users' opinion and, therefore, measuring the quality of service in each application requires a specific instrument. This paper will introduce an instrument to measure the QoS offered to users by a general Web application for Electronic Health Records (EHRs). The collection of opinions from a pilot sample and the performance of an explanatory factor analysis will bring together the factors that best sum up the quality of an EHRs application. Subsequently, a confirmatory factor analysis will be performed to make the study reliable and, as its name suggests, to confirm that indeed the structure of the instrument developed measures the QoS in accordance with the requirements of the users.

A modify ant colony optimization for the grid jobs scheduling problem with QoS requirements

NASA Astrophysics Data System (ADS)

Pu, Xun; Lu, XianLiang

2011-10-01

Job scheduling with customers' quality of service (QoS) requirement is challenging in grid environment. In this paper, we present a modify Ant colony optimization (MACO) for the Job scheduling problem in grid. Instead of using the conventional construction approach to construct feasible schedules, the proposed algorithm employs a decomposition method to satisfy the customer's deadline and cost requirements. Besides, a new mechanism of service instances state updating is embedded to improve the convergence of MACO. Experiments demonstrate the effectiveness of the proposed algorithm.

QaaS (quality as a service) model for web services using big data technologies

NASA Astrophysics Data System (ADS)

Ahmad, Faisal; Sarkar, Anirban

2017-10-01

Quality of service (QoS) determines the service usability and utility and both of which influence the service selection process. The QoS varies from one service provider to other. Each web service has its own methodology for evaluating QoS. The lack of transparent QoS evaluation model makes the service selection challenging. Moreover, most QoS evaluation processes do not consider their historical data which not only helps in getting more accurate QoS but also helps for future prediction, recommendation and knowledge discovery. QoS driven service selection demands a model where QoS can be provided as a service to end users. This paper proposes a layered QaaS (quality as a service) model in the same line as PaaS and software as a service, where users can provide QoS attributes as inputs and the model returns services satisfying the user's QoS expectation. This paper covers all the key aspects in this context, like selection of data sources, its transformation, evaluation, classification and storage of QoS. The paper uses server log as the source for evaluating QoS values, common methodology for its evaluation and big data technologies for its transformation and analysis. This paper also establishes the fact that Spark outperforms the Pig with respect to evaluation of QoS from logs.

An Automated End-To Multi-Agent Qos Based Architecture for Selection of Geospatial Web Services

NASA Astrophysics Data System (ADS)

Shah, M.; Verma, Y.; Nandakumar, R.

2012-07-01

Over the past decade, Service-Oriented Architecture (SOA) and Web services have gained wide popularity and acceptance from researchers and industries all over the world. SOA makes it easy to build business applications with common services, and it provides like: reduced integration expense, better asset reuse, higher business agility, and reduction of business risk. Building of framework for acquiring useful geospatial information for potential users is a crucial problem faced by the GIS domain. Geospatial Web services solve this problem. With the help of web service technology, geospatial web services can provide useful geospatial information to potential users in a better way than traditional geographic information system (GIS). A geospatial Web service is a modular application designed to enable the discovery, access, and chaining of geospatial information and services across the web that are often both computation and data-intensive that involve diverse sources of data and complex processing functions. With the proliferation of web services published over the internet, multiple web services may provide similar functionality, but with different non-functional properties. Thus, Quality of Service (QoS) offers a metric to differentiate the services and their service providers. In a quality-driven selection of web services, it is important to consider non-functional properties of the web service so as to satisfy the constraints or requirements of the end users. The main intent of this paper is to build an automated end-to-end multi-agent based solution to provide the best-fit web service to service requester based on QoS.

A QoS Framework with Traffic Request in Wireless Mesh Network

NASA Astrophysics Data System (ADS)

Fu, Bo; Huang, Hejiao

In this paper, we consider major issues in ensuring greater Quality-of-Service (QoS) in Wireless Mesh Networks (WMNs), specifically with regard to reliability and delay. To this end, we use traffic request to record QoS requirements of data flows. In order to achieve required QoS for all data flows efficiently and with high portability, we develop Network State Update Algorithm. All assumptions, definitions, and algorithms are made exclusively with WMNs in mind, guaranteeing the portability of our framework to various environments in WMNs. The simulation results in proof that our framework is correct.

MPEG-2 Over Asynchronous Transfer Mode (ATM) Over Satellite Quality of Service (QoS) Experiments: Laboratory Tests

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Frantz, Brian D.; Spells, Marcus J.

1998-01-01

Asynchronous transfer mode (ATM) quality of service (QoS) experiments were performed using MPEG-2 (ATM application layer 5, AAL5) over ATM over an emulated satellite link. The purpose of these experiments was to determine the free-space link quality necessary to transmit high-quality multimedia information by using the ATM protocol. The detailed test plan and test configuration are described herein as are the test results. MPEG-2 transport streams were baselined in an errored environment, followed by a series of tests using, MPEG-2 over ATM. Errors were created both digitally as well as in an IF link by using a satellite modem and commercial gaussian noise test set for two different MPEG-2 decoder implementations. The results show that ITU-T Recommendation 1.356 Class 1, stringent ATM applications will require better link quality than currently specified; in particular, cell loss ratios of better than 1.0 x 10(exp -8) and cell error ratios of better than 1.0 x 10(exp -7) are needed. These tests were conducted at the NASA Lewis Research Center in support of satellite-ATM interoperability research.

Mission-Related Execution and Planning Through Quality of Service Methods

DTIC Science & Technology

2010-06-01

which maximizes a mission effectiveness functions is the ideal driver of QoS mechanisms. Service Quality Quality of Service may also exist in other...However, service quality is the originating concept of QoS and is the level of performance which one entity expects from another, including non-IT SoSs... Service quality may also be reflected in the context of a system’s purpose or an organization’s mission. Putting level of service values and

Unified study of Quality of Service (QoS) in OPS/OBS networks

NASA Astrophysics Data System (ADS)

Hailu, Dawit Hadush; Lema, Gebrehiwet Gebrekrstos; Yekun, Ephrem Admasu; Kebede, Samrawit Haylu

2017-07-01

With the growth of Internet traffic, an inevitable use of optical networks provide a large bandwidth, fast data transmission rates and Quality of Service (QoS) support. Currently, Optical Burst Switched (OBS)/Optical Packet Switched (OPS) networks are under study as future solutions for addressing the increase demand of Internet traffic. However, due to their high blocking probability in the intermediate nodes they have been delayed in the industries. Packet loss in OBS/OPS networks is mainly occur due to contention. Hence, the contribution of this study is to analyze the file loss ratio (FLR), packet overhead and number of disjoint paths, and processing delay over Coded Packet Transport (CPT) scheme for OBS/OPS network using simulation. The simulations show that CPT scheme reduces the FLR in OBS/OPS network for the evaluated scenarios since the data packets are chopped off into blocks of the data packet for transmission over a network. Simulation results for secrecy and survivability are verified with the help of the analytical model to define the operational range of CPT scheme.

Evaluation of AL-FEC performance for IP television services QoS

NASA Astrophysics Data System (ADS)

Mammi, E.; Russo, G.; Neri, A.

2010-01-01

The IP television services quality is a critical issue because of the nature of transport infrastructure. Packet loss is the main cause of service degradation in such kind of network platforms. The use of forward error correction (FEC) techniques in the application layer (AL-FEC), between the source of TV service (video server) and the user terminal, seams to be an efficient strategy to counteract packet losses alternatively or in addiction to suitable traffic management policies (only feasible in "managed networks"). A number of AL-FEC techniques have been discussed in literature and proposed for inclusion in TV over IP international standards. In this paper a performance evaluation of the AL-FEC defined in SMPTE 2022-1 standard is presented. Different typical events occurring in IP networks causing different types (in terms of statistic distribution) of IP packet losses have been studied and AL-FEC performance to counteract these kind of losses have been evaluated. The performed analysis has been carried out in view of fulfilling the TV services QoS requirements that are usually very demanding. For managed networks, this paper envisages a strategy to combine the use of AL-FEC with the set-up of a transport quality based on FEC packets prioritization. Promising results regard this kind of strategy have been obtained.

Dynamic Hop Service Differentiation Model for End-to-End QoS Provisioning in Multi-Hop Wireless Networks

NASA Astrophysics Data System (ADS)

Youn, Joo-Sang; Seok, Seung-Joon; Kang, Chul-Hee

This paper presents a new QoS model for end-to-end service provisioning in multi-hop wireless networks. In legacy IEEE 802.11e based multi-hop wireless networks, the fixed assignment of service classes according to flow's priority at every node causes priority inversion problem when performing end-to-end service differentiation. Thus, this paper proposes a new QoS provisioning model called Dynamic Hop Service Differentiation (DHSD) to alleviate the problem and support effective service differentiation between end-to-end nodes. Many previous works for QoS model through the 802.11e based service differentiation focus on packet scheduling on several service queues with different service rate and service priority. Our model, however, concentrates on a dynamic class selection scheme, called Per Hop Class Assignment (PHCA), in the node's MAC layer, which selects a proper service class for each packet, in accordance with queue states and service requirement, in every node along the end-to-end route of the packet. The proposed QoS solution is evaluated using the OPNET simulator. The simulation results show that the proposed model outperforms both best-effort and 802.11e based strict priority service models in mobile ad hoc environments.

SLA-aware differentiated QoS in elastic optical networks

NASA Astrophysics Data System (ADS)

Agrawal, Anuj; Vyas, Upama; Bhatia, Vimal; Prakash, Shashi

2017-07-01

The quality of service (QoS) offered by optical networks can be improved by accurate provisioning of service level specifications (SLSs) included in the service level agreement (SLA). A large number of users coexisting in the network require different services. Thus, a pragmatic network needs to offer a differentiated QoS to a variety of users according to the SLA contracted for different services at varying costs. In conventional wavelength division multiplexed (WDM) optical networks, service differentiation is feasible only for a limited number of users because of its fixed-grid structure. Newly introduced flex-grid based elastic optical networks (EONs) are more adaptive to traffic requirements as compared to the WDM networks because of the flexibility in their grid structure. Thus, we propose an efficient SLA provisioning algorithm with improved QoS for these flex-grid EONs empowered by optical orthogonal frequency division multiplexing (O-OFDM). The proposed algorithm, called SLA-aware differentiated QoS (SADQ), employs differentiation at the level of routing, spectrum allocation, and connection survivability. The proposed SADQ aims to accurately provision the SLA using such multilevel differentiation with an objective to improve the spectrum utilization from the network operator's perspective. SADQ is evaluated for three different CoSs under various traffic demand patterns and for different ratios of the number of requests belonging to the three considered CoSs. We propose two new SLA metrics for the improvement of functional QoS requirements, namely, security, confidentiality and survivability of high class of service (CoS) traffic. Since, to the best of our knowledge, the proposed SADQ is the first scheme in optical networks to employ exhaustive differentiation at the levels of routing, spectrum allocation, and survivability in a single algorithm, we first compare the performance of SADQ in EON and currently deployed WDM networks to assess the

RACOON: a multiuser QoS design for mobile wireless body area networks.

PubMed

Cheng, Shihheng; Huang, Chingyao; Tu, Chun Chen

2011-10-01

In this study, Random Contention-based Resource Allocation (RACOON) medium access control (MAC) protocol is proposed to support the quality of service (QoS) for multi-user mobile wireless body area networks (WBANs). Different from existing QoS designs that focus on a single WBAN, a multiuser WBAN QoS should further consider both inter-WBAN interference and inter-WBAN priorities. Similar problems have been studied in both overlapped wireless local area networks (WLANs) and Bluetooth piconets that need QoS supports. However, these solutions are designed for non-medical transmissions that do not consider any priority scheme for medical applications. Most importantly, these studies focus on only static or low mobility networks. Network mobility of WBANs will introduce unnecessary inter-network collisions and energy waste, which are not considered by these solutions. The proposed multiuser-QoS protocol, RACOON, simultaneously satisfies the inter WBAN QoS requirements and overcomes the performance degradation caused by WBAN mobility. Simulation results verify that RACOON provides better latency and energy control, as compared with WBAN QoS protocols without considering the inter-WBAN requirements.

QOS-aware error recovery in wireless body sensor networks using adaptive network coding.

PubMed

Razzaque, Mohammad Abdur; Javadi, Saeideh S; Coulibaly, Yahaya; Hira, Muta Tah

2014-12-29

Wireless body sensor networks (WBSNs) for healthcare and medical applications are real-time and life-critical infrastructures, which require a strict guarantee of quality of service (QoS), in terms of latency, error rate and reliability. Considering the criticality of healthcare and medical applications, WBSNs need to fulfill users/applications and the corresponding network's QoS requirements. For instance, for a real-time application to support on-time data delivery, a WBSN needs to guarantee a constrained delay at the network level. A network coding-based error recovery mechanism is an emerging mechanism that can be used in these systems to support QoS at very low energy, memory and hardware cost. However, in dynamic network environments and user requirements, the original non-adaptive version of network coding fails to support some of the network and user QoS requirements. This work explores the QoS requirements of WBSNs in both perspectives of QoS. Based on these requirements, this paper proposes an adaptive network coding-based, QoS-aware error recovery mechanism for WBSNs. It utilizes network-level and user-/application-level information to make it adaptive in both contexts. Thus, it provides improved QoS support adaptively in terms of reliability, energy efficiency and delay. Simulation results show the potential of the proposed mechanism in terms of adaptability, reliability, real-time data delivery and network lifetime compared to its counterparts.

Mapping of multiple parameter m-health scenarios to mobile WiMAX QoS variables.

PubMed

Alinejad, Ali; Philip, N; Istepanian, R S H

2011-01-01

Multiparameter m-health scenarios with bandwidth demanding requirements will be one of key applications in future 4 G mobile communication systems. These applications will potentially require specific spectrum allocations with higher quality of service requirements. Furthermore, one of the key 4 G technologies targeting m-health will be medical applications based on WiMAX systems. Hence, it is timely to evaluate such multiple parametric m-health scenarios over mobile WiMAX networks. In this paper, we address the preliminary performance analysis of mobile WiMAX network for multiparametric telemedical scenarios. In particular, we map the medical QoS to typical WiMAX QoS parameters to optimise the performance of these parameters in typical m-health scenario. Preliminary performance analyses of the proposed multiparametric scenarios are evaluated to provide essential information for future medical QoS requirements and constraints in these telemedical network environments.

Provision of QoS for Multimedia Services in IEEE 802.11 Wireless Network

DTIC Science & Technology

2006-10-01

Provision of QoS for Multimedia Services in IEEE 802.11 Wireless Network. In Dynamic Communications Management (pp. 10-1 – 10-16). Meeting Proceedings...mechanisms have been used for managing a limited bandwidth link within the IPv6 military narrowband network. The detailed description of these...confirms that implemented video rate adaptation mechanism enables improvement of qaulity of video transfer. Provision of QoS for Multimedia Services in

Quality of service provision assessment in the healthcare information and telecommunications infrastructures.

PubMed

Babulak, Eduard

2006-01-01

The continuous increase in the complexity and the heterogeneity of corporate and healthcare telecommunications infrastructures will require new assessment methods of quality of service (QoS) provision that are capable of addressing all engineering and social issues with much faster speeds. Speed and accessibility to any information at any time from anywhere will create global communications infrastructures with great performance bottlenecks that may put in danger human lives, power supplies, national economy and security. Regardless of the technology supporting the information flows, the final verdict on the QoS is made by the end user. The users' perception of telecommunications' network infrastructure QoS provision is critical to the successful business management operation of any organization. As a result, it is essential to assess the QoS Provision in the light of user's perception. This article presents a cost effective methodology to assess the user's perception of quality of service provision utilizing the existing Staffordshire University Network (SUN) by adding a component of measurement to the existing model presented by Walker. This paper presents the real examples of CISCO Networking Solutions for Health Care givers and offers a cost effective approach to assess the QoS provision within the campus network, which could be easily adapted to any health care organization or campus network in the world.

An MBS-Assisted Femtocell Transmit Power Control Scheme with Mobile User QoS Guarantee in 2-Tier Heterogeneous Femtocell Networks

PubMed Central

Yang, Chih-Cheng; Sheu, Shiann-Tsong

2013-01-01

This study investigates how to adjust the transmit power of femto base station (FBS) to mitigate interference problems between the FBSs and mobile users (MUs) in the 2-tier heterogeneous femtocell networks. A common baseline of deploying the FBS to increase the indoor access bandwidth requires that the FBS operation will not affect outdoor MUs operation with their quality-of-service (QoS) requirements. To tackle this technical problem, an FBS transmit power adjustment (FTPA) algorithm is proposed to adjust the FBS transmit power (FTP) to avoid unwanted cochannel interference (CCI) with the neighboring MUs in downlink transmission. FTPA reduces the FTP to serve its femto users (FUs) according to the QoS requirements of the nearest neighboring MUs to the FBS so that the MU QoS requirement is guaranteed. Simulation results demonstrate that FTPA can achieve a low MU outage probability as well as serve FUs without violating the MU QoS requirements. Simulation results also reveal that FTPA has better performance on voice and video services which are the major trend of future multimedia communication in the NGN. PMID:24391461

An MBS-assisted femtocell transmit power control scheme with mobile user QoS guarantee in 2-tier heterogeneous femtocell networks.

PubMed

Chen, Jenhui; Yang, Chih-Cheng; Sheu, Shiann-Tsong

2013-01-01

This study investigates how to adjust the transmit power of femto base station (FBS) to mitigate interference problems between the FBSs and mobile users (MUs) in the 2-tier heterogeneous femtocell networks. A common baseline of deploying the FBS to increase the indoor access bandwidth requires that the FBS operation will not affect outdoor MUs operation with their quality-of-service (QoS) requirements. To tackle this technical problem, an FBS transmit power adjustment (FTPA) algorithm is proposed to adjust the FBS transmit power (FTP) to avoid unwanted cochannel interference (CCI) with the neighboring MUs in downlink transmission. FTPA reduces the FTP to serve its femto users (FUs) according to the QoS requirements of the nearest neighboring MUs to the FBS so that the MU QoS requirement is guaranteed. Simulation results demonstrate that FTPA can achieve a low MU outage probability as well as serve FUs without violating the MU QoS requirements. Simulation results also reveal that FTPA has better performance on voice and video services which are the major trend of future multimedia communication in the NGN.

A Mobility-Aware QoS Signaling Protocol for Ambient Networks

NASA Astrophysics Data System (ADS)

Jeong, Seong-Ho; Lee, Sung-Hyuck; Bang, Jongho

Mobility-aware quality of service (QoS) signaling is crucial to provide seamless multimedia services in the ambient environment where mobile nodes may move frequently between different wireless access networks. The mobility of an IP-based node in ambient networks affects routing paths, and as a result, can have a significant impact on the operation and state management of QoS signaling protocols. In this paper, we first analyze the impact of mobility on QoS signaling protocols and how the protocols operate in mobility scenarios. We then propose an efficient mobility-aware QoS signaling protocol which can operate adaptively in ambient networks. The key features of the protocol include the fast discovery of a crossover node where the old and new paths converge or diverge due to handover and the localized state management for seamless services. Our analytical and simulation/experimental results show that the proposed/implemented protocol works better than existing protocols in the IP-based mobile environment.

Distributed sensor architecture for intelligent control that supports quality of control and quality of service.

PubMed

Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

2015-02-25

This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems.

Distributed Sensor Architecture for Intelligent Control that Supports Quality of Control and Quality of Service

PubMed Central

Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Simarro, Raúl; Benet, Ginés

2015-01-01

This paper is part of a study of intelligent architectures for distributed control and communications systems. The study focuses on optimizing control systems by evaluating the performance of middleware through quality of service (QoS) parameters and the optimization of control using Quality of Control (QoC) parameters. The main aim of this work is to study, design, develop, and evaluate a distributed control architecture based on the Data-Distribution Service for Real-Time Systems (DDS) communication standard as proposed by the Object Management Group (OMG). As a result of the study, an architecture called Frame-Sensor-Adapter to Control (FSACtrl) has been developed. FSACtrl provides a model to implement an intelligent distributed Event-Based Control (EBC) system with support to measure QoS and QoC parameters. The novelty consists of using, simultaneously, the measured QoS and QoC parameters to make decisions about the control action with a new method called Event Based Quality Integral Cycle. To validate the architecture, the first five Braitenberg vehicles have been implemented using the FSACtrl architecture. The experimental outcomes, demonstrate the convenience of using jointly QoS and QoC parameters in distributed control systems. PMID:25723145

An Efficient and QoS Supported Multichannel MAC Protocol for Vehicular Ad Hoc Networks

PubMed Central

Tan, Guozhen; Yu, Chao

2017-01-01

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety (transport efficiency and infotainment) applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. Different types of applications require different levels Quality-of-Service (QoS) support. Recently, transport efficiency and infotainment applications (e.g., electronic map download and Internet access) have received more and more attention, and this kind of applications is expected to become a big market driver in a near future. In this paper, we propose an Efficient and QoS supported Multichannel Medium Access Control (EQM-MAC) protocol for VANETs in a highway environment. The EQM-MAC protocol utilizes the service channel resources for non-safety message transmissions during the whole synchronization interval, and it dynamically adjusts minimum contention window size for different non-safety services according to the traffic conditions. Theoretical model analysis and extensive simulation results show that the EQM-MAC protocol can support QoS services, while ensuring the high saturation throughput and low transmission delay for non-safety applications. PMID:28991217

Controlling QoS in a collaborative multimedia environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alfano, M.; Sigle, R.

1996-12-31

A collaborative multimedia environment allows users to work remotely on common projects by sharing applications (e.g., CAD tools, text editors, white boards) and simultaneously communicate audiovisually. Several dedicated applications (e.g., MBone tools) exist for transmitting video, audio and data between users. Due to the fact that they have been developed for the Internet which does not provide any Quality of Service (QoS) guarantee, these applications do not or only partially support specification of QoS requirements by the user. In addition, they all come with different user interfaces. In this paper we first discuss the problems that we experienced both atmore » the host and network levels when executing a multimedia application and varying its resource requirements. We then present the architectural details of a collaborative multimedia environment (CME) that we have been developing in order to help a user to set up and control a collaborative multimedia session.« less

Fairness of QoS supporting in optical burst switching

NASA Astrophysics Data System (ADS)

Xuan, Xuelei; Liu, Hua; Chen, Chunfeng; Zhang, Zhizhong

2004-04-01

In this paper we investigate the fairness problem of offset-time-based quality of service (QoS) scheme proposed by Qiao and Dixit in optical burst switching (OBS) networks. In the proposed schemes, QoS relies on the fact that the requests for reservation further into the future, but for practical, benchmark offset-time of data bursts at the intermediate nodes is not equal to each other. Here, a new offset-time-based QoS scheme is introduced, where data bursts are classified according to their offset-time and isolated in the wavelength domain or time domain to achieve the parallel reservation. Through simulation, it is found that this scheme achieves fairness among data bursts with different priority.

Dynamic quality of service model for improving performance of multimedia real-time transmission in industrial networks.

PubMed

Gopalakrishnan, Ravichandran C; Karunakaran, Manivannan

2014-01-01

Nowadays, quality of service (QoS) is very popular in various research areas like distributed systems, multimedia real-time applications and networking. The requirements of these systems are to satisfy reliability, uptime, security constraints and throughput as well as application specific requirements. The real-time multimedia applications are commonly distributed over the network and meet various time constraints across networks without creating any intervention over control flows. In particular, video compressors make variable bit-rate streams that mismatch the constant-bit-rate channels typically provided by classical real-time protocols, severely reducing the efficiency of network utilization. Thus, it is necessary to enlarge the communication bandwidth to transfer the compressed multimedia streams using Flexible Time Triggered- Enhanced Switched Ethernet (FTT-ESE) protocol. FTT-ESE provides automation to calculate the compression level and change the bandwidth of the stream. This paper focuses on low-latency multimedia transmission over Ethernet with dynamic quality-of-service (QoS) management. This proposed framework deals with a dynamic QoS for multimedia transmission over Ethernet with FTT-ESE protocol. This paper also presents distinct QoS metrics based both on the image quality and network features. Some experiments with recorded and live video streams show the advantages of the proposed framework. To validate the solution we have designed and implemented a simulator based on the Matlab/Simulink, which is a tool to evaluate different network architecture using Simulink blocks.

Joint Cross-Layer Design for Wireless QoS Content Delivery

NASA Astrophysics Data System (ADS)

Chen, Jie; Lv, Tiejun; Zheng, Haitao

2005-12-01

In this paper, we propose a joint cross-layer design for wireless quality-of-service (QoS) content delivery. Central to our proposed cross-layer design is the concept of adaptation. Adaptation represents the ability to adjust protocol stacks and applications to respond to channel variations. We focus our cross-layer design especially on the application, media access control (MAC), and physical layers. The network is designed based on our proposed fast frequency-hopping orthogonal frequency division multiplex (OFDM) technique. We also propose a QoS-awareness scheduler and a power adaptation transmission scheme operating at both the base station and mobile sides. The proposed MAC scheduler coordinates the transmissions of an IP base station and mobile nodes. The scheduler also selects appropriate transmission formats and packet priorities for individual users based on current channel conditions and the users' QoS requirements. The test results show that our cross-layer design provides an excellent framework for wireless QoS content delivery.

Fuzzy Logic Control Based QoS Management in Wireless Sensor/Actuator Networks

PubMed Central

Xia, Feng; Zhao, Wenhong; Sun, Youxian; Tian, Yu-Chu

2007-01-01

Wireless sensor/actuator networks (WSANs) are emerging rapidly as a new generation of sensor networks. Despite intensive research in wireless sensor networks (WSNs), limited work has been found in the open literature in the field of WSANs. In particular, quality-of-service (QoS) management in WSANs remains an important issue yet to be investigated. As an attempt in this direction, this paper develops a fuzzy logic control based QoS management (FLC-QM) scheme for WSANs with constrained resources and in dynamic and unpredictable environments. Taking advantage of the feedback control technology, this scheme deals with the impact of unpredictable changes in traffic load on the QoS of WSANs. It utilizes a fuzzy logic controller inside each source sensor node to adapt sampling period to the deadline miss ratio associated with data transmission from the sensor to the actuator. The deadline miss ratio is maintained at a pre-determined desired level so that the required QoS can be achieved. The FLC-QM has the advantages of generality, scalability, and simplicity. Simulation results show that the FLC-QM can provide WSANs with QoS support. PMID:28903288

A quality of service negotiation procedure for distributed multimedia presentational applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafid, A.; Bochmann, G.V.; Kerherve, B.

Most of current approaches in designing and implementing distributed multimedia (MM) presentational applications, e.g. news-on-demand, have concentrated on the performance of the continuous media file servers in terms of seek time overhead, and real-time disk scheduling; particularly the QoS negotiation mechanisms they provide are used in a rather static manner that is, these mechanisms are restricted to the evaluation of the capacity of certain system components, e.g. file server a priori known to support a specific quality of service (QoS). In contrast to those approaches, we propose a general QoS negotiation framework that supports the dynamic choice of a configurationmore » of system components to support the QoS requirements of the user of a specific application: we consider different possible system configurations and select an optimal one to provide the appropriate QoS support. In this paper we document the design and implementation of a QoS negotiation procedure for distributed MM presentational applications, such as news-on-demand. The negotiation procedure described here is an instantiation of the general framework for QoS negotiation which was developed earlier Our proposal differs in many respect with the negotiation functions provided by existing approaches: (1) the negotiation process uses an optimization approach to find a configuration of system components which supports the user requirements, (2) the negotiation process supports the negotiation of a MM document and not only a single monomedia object, (3) the QoS negotiation takes into account the cost to the user, and (4) the negotiation process may be used to support automatic adaptation to react to QoS degradations, without intervention by the user/application.« less

Dynamic quality of service differentiation using fixed code weight in optical CDMA networks

NASA Astrophysics Data System (ADS)

Kakaee, Majid H.; Essa, Shawnim I.; Abd, Thanaa H.; Seyedzadeh, Saleh

2015-11-01

The emergence of network-driven applications, such as internet, video conferencing, and online gaming, brings in the need for a network the environments with capability of providing diverse Quality of Services (QoS). In this paper, a new code family of novel spreading sequences, called a Multi-Service (MS) code, has been constructed to support multiple services in Optical- Code Division Multiple Access (CDMA) system. The proposed method uses fixed weight for all services, however reducing the interfering codewords for the users requiring higher QoS. The performance of the proposed code is demonstrated using mathematical analysis. It shown that the total number of served users with satisfactory BER of 10-9 using NB=2 is 82, while they are only 36 and 10 when NB=3 and 4 respectively. The developed MS code is compared with variable-weight codes such as Variable Weight-Khazani Syed (VW-KS) and Multi-Weight-Random Diagonal (MW-RD). Different numbers of basic users (NB) are used to support triple-play services (audio, data and video) with different QoS requirements. Furthermore, reference to the BER of 10-12, 10-9, and 10-3 for video, data and audio, respectively, the system can support up to 45 total users. Hence, results show that the technique can clearly provide a relative QoS differentiation with lower value of basic users can support larger number of subscribers as well as better performance in terms of acceptable BER of 10-9 at fixed code weight.

Quality and Business Offer Driven Selection of Web Services for Compositions

NASA Astrophysics Data System (ADS)

D'Mello, Demian Antony; Ananthanarayana, V. S.

The service composition makes use of the existing services to produce a new value added service to execute the complex business process. The service discovery finds the suitable services (candidates) for the various tasks of the composition based on the functionality. The service selection in composition assigns the best candidate for each tasks of the pre-structured composition plan based on the non-functional properties. In this paper, we propose the broker based architecture for the QoS and business offer aware Web service compositions. The broker architecture facilitates the registration of a new composite service into three different registries. The broker publishes service information into the service registry and QoS into the QoS registry. The business offers of the composite Web service are published into a separate repository called business offer (BO) registry. The broker employs the mechanism for the optimal assignment of the Web services to the individual tasks of the composition. The assignment is based on the composite service providers’s (CSP) variety of requirements defined on the QoS and business offers. The broker also computes the QoS of resulting composition and provides the useful information for the CSP to publish thier business offers.

Bio-Inspired Distributed Transmission Power Control Considering QoS Fairness in Wireless Body Area Sensor Networks

PubMed Central

2017-01-01

Recently, the development of wireless body area sensor network (WBASN) has accelerated due to the rapid development of wireless technology. In the WBASN environment, many WBASNs coexist where communication ranges overlap with each other, resulting in the possibility of interference. Although nodes in a WBASN typically operate at a low power level, to avoid adversely affecting the human body, high transmission rates may be required to support some applications. In addition to this, since many varieties of applications exist in the WBASN environment, each prospective user may have different quality of service (QoS) requirements. Hence, the following issues should be considered in the WBASN environment: (1) interference between adjacent WBASNs, which influences the performance of a specific system, and (2) the degree of satisfaction on the QoS of each user, i.e., the required QoS such as user throughput should be considered to ensure that all users in the network are provided with a fair QoS satisfaction. Thus, in this paper, we propose a transmission power adjustment algorithm that addresses interference problems and guarantees QoS fairness between users. First, we use a new utility function to measure the degree of the satisfaction on the QoS for each user. Then, the transmission power of each sensor node is calculated using the Cucker–Smale model, and the QoS satisfaction of each user is synchronized dispersively. The results of simulations show that the proposed algorithm performs better than existing algorithms, with respect to QoS fairness and energy efficiency. PMID:29036924

Bio-Inspired Distributed Transmission Power Control Considering QoS Fairness in Wireless Body Area Sensor Networks.

PubMed

Lee, Chan-Jae; Jung, Ji-Young; Lee, Jung-Ryun

2017-10-14

Recently, the development of wireless body area sensor network (WBASN) has accelerated due to the rapid development of wireless technology. In the WBASN environment, many WBASNs coexist where communication ranges overlap with each other, resulting in the possibility of interference. Although nodes in a WBASN typically operate at a low power level, to avoid adversely affecting the human body, high transmission rates may be required to support some applications. In addition to this, since many varieties of applications exist in the WBASN environment, each prospective user may have different quality of service (QoS) requirements. Hence, the following issues should be considered in the WBASN environment: (1) interference between adjacent WBASNs, which influences the performance of a specific system, and (2) the degree of satisfaction on the QoS of each user, i.e., the required QoS such as user throughput should be considered to ensure that all users in the network are provided with a fair QoS satisfaction. Thus, in this paper, we propose a transmission power adjustment algorithm that addresses interference problems and guarantees QoS fairness between users. First, we use a new utility function to measure the degree of the satisfaction on the QoS for each user. Then, the transmission power of each sensor node is calculated using the Cucker-Smale model, and the QoS satisfaction of each user is synchronized dispersively. The results of simulations show that the proposed algorithm performs better than existing algorithms, with respect to QoS fairness and energy efficiency.

ATM QoS Experiments Using TCP Applications: Performance of TCP/IP Over ATM in a Variety of Errored Links

NASA Technical Reports Server (NTRS)

Frantz, Brian D.; Ivancic, William D.

2001-01-01

Asynchronous Transfer Mode (ATM) Quality of Service (QoS) experiments using the Transmission Control Protocol/Internet Protocol (TCP/IP) were performed for various link delays. The link delay was set to emulate a Wide Area Network (WAN) and a Satellite Link. The purpose of these experiments was to evaluate the ATM QoS requirements for applications that utilize advance TCP/IP protocols implemented with large windows and Selective ACKnowledgements (SACK). The effects of cell error, cell loss, and random bit errors on throughput were reported. The detailed test plan and test results are presented herein.

QoS Challenges and Opportunities in Wireless Sensor/Actuator Networks

PubMed Central

Xia, Feng

2008-01-01

A wireless sensor/actuator network (WSAN) is a group of sensors and actuators that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Actuators react to this information by performing appropriate actions. WSANs thus enable cyber systems to monitor and manipulate the behavior of the physical world. WSANs are growing at a tremendous pace, just like the exploding evolution of Internet. Supporting quality of service (QoS) will be of critical importance for pervasive WSANs that serve as the network infrastructure of diverse applications. To spark new research and development interests in this field, this paper examines and discusses the requirements, critical challenges, and open research issues on QoS management in WSANs. A brief overview of recent progress is given. PMID:27879755

McMAC: Towards a MAC Protocol with Multi-Constrained QoS Provisioning for Diverse Traffic in Wireless Body Area Networks

PubMed Central

Monowar, Muhammad Mostafa; Hassan, Mohammad Mehedi; Bajaber, Fuad; Al-Hussein, Musaed; Alamri, Atif

2012-01-01

The emergence of heterogeneous applications with diverse requirements for resource-constrained Wireless Body Area Networks (WBANs) poses significant challenges for provisioning Quality of Service (QoS) with multi-constraints (delay and reliability) while preserving energy efficiency. To address such challenges, this paper proposes McMAC, a MAC protocol with multi-constrained QoS provisioning for diverse traffic classes in WBANs. McMAC classifies traffic based on their multi-constrained QoS demands and introduces a novel superframe structure based on the “transmit-whenever-appropriate” principle, which allows diverse periods for diverse traffic classes according to their respective QoS requirements. Furthermore, a novel emergency packet handling mechanism is proposed to ensure packet delivery with the least possible delay and the highest reliability. McMAC is also modeled analytically, and extensive simulations were performed to evaluate its performance. The results reveal that McMAC achieves the desired delay and reliability guarantee according to the requirements of a particular traffic class while achieving energy efficiency. PMID:23202224

Evaluation of QoS supported in Network Mobility NEMO environments

NASA Astrophysics Data System (ADS)

Hussien, L. F.; Abdalla, A. H.; Habaebi, M. H.; Khalifa, O. O.; Hassan, W. H.

2013-12-01

Network mobility basic support (NEMO BS) protocol is an entire network, roaming as a unit which changes its point of attachment to the Internet and consequently its reachability in the network topology. NEMO BS doesn't provide QoS guarantees to its users same as traditional Internet IP and Mobile IPv6 as well. Typically, all the users will have same level of services without considering about their application requirements. This poses a problem to real-time applications that required QoS guarantees. To gain more effective control of the network, incorporated QoS is needed. Within QoS-enabled network the traffic flow can be distributed to various priorities. Also, the network bandwidth and resources can be allocated to different applications and users. Internet Engineering Task Force (IETF) working group has proposed several QoS solutions for static network such as IntServ, DiffServ and MPLS. These QoS solutions are designed in the context of a static environment (i.e. fixed hosts and networks). However, they are not fully adapted to mobile environments. They essentially demands to be extended and adjusted to meet up various challenges involved in mobile environments. With existing QoS mechanisms many proposals have been developed to provide QoS for individual mobile nodes (i.e. host mobility). In contrary, research based on the movement of the whole mobile network in IPv6 is still undertaking by the IETF working groups (i.e. network mobility). Few researches have been done in the area of providing QoS for roaming networks. Therefore, this paper aims to review and investigate (previous /and current) related works that have been developed to provide QoS in mobile network. Consequently, a new proposed scheme will be introduced to enhance QoS within NEMO environment, achieving by which seamless mobility to users of mobile network node (MNN).

QoS support for end users of I/O-intensive applications using shared storage systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Marion Kei; Zhang, Xuechen; Jiang, Song

2011-01-19

I/O-intensive applications are becoming increasingly common on today's high-performance computing systems. While performance of compute-bound applications can be effectively guaranteed with techniques such as space sharing or QoS-aware process scheduling, it remains a challenge to meet QoS requirements for end users of I/O-intensive applications using shared storage systems because it is difficult to differentiate I/O services for different applications with individual quality requirements. Furthermore, it is difficult for end users to accurately specify performance goals to the storage system using I/O-related metrics such as request latency or throughput. As access patterns, request rates, and the system workload change in time,more » a fixed I/O performance goal, such as bounds on throughput or latency, can be expensive to achieve and may not lead to a meaningful performance guarantees such as bounded program execution time. We propose a scheme supporting end-users QoS goals, specified in terms of program execution time, in shared storage environments. We automatically translate the users performance goals into instantaneous I/O throughput bounds using a machine learning technique, and use dynamically determined service time windows to efficiently meet the throughput bounds. We have implemented this scheme in the PVFS2 parallel file system and have conducted an extensive evaluation. Our results show that this scheme can satisfy realistic end-user QoS requirements by making highly efficient use of the I/O resources. The scheme seeks to balance programs attainment of QoS requirements, and saves as much of the remaining I/O capacity as possible for best-effort programs.« less

A QoS adaptive multimedia transport system: design, implementation and experiences

NASA Astrophysics Data System (ADS)

Campbell, Andrew; Coulson, Geoff

1997-03-01

The long awaited `new environment' of high speed broadband networks and multimedia applications is fast becoming a reality. However, few systems in existence today, whether they be large scale pilots or small scale test-beds in research laboratories, offer a fully integrated and flexible environment where multimedia applications can maximally exploit the quality of service (QoS) capabilities of supporting networks and end-systems. In this paper we describe the implementation of an adaptive transport system that incorporates a QoS oriented API and a range of mechanisms to assist applications in exploiting QoS and adapting to fluctuations in QoS. The system, which is an instantiation of the Lancaster QoS Architecture, is implemented in a multi ATM switch network environment with Linux based PC end systems and continuous media file servers. A performance evaluation of the system configured to support video-on-demand application scenario is presented and discussed. Emphasis is placed on novel features of the system and on their integration into a complete prototype. The most prominent novelty of our design is a `distributed QoS adaptation' scheme which allows applications to delegate to the system responsibility for augmenting and reducing the perceptual quality of video and audio flows when resource availability increases or decreases.

Multi-Agent Architecture with Support to Quality of Service and Quality of Control

NASA Astrophysics Data System (ADS)

Poza-Luján, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, Jose-Enrique

Multi Agent Systems (MAS) are one of the most suitable frameworks for the implementation of intelligent distributed control system. Agents provide suitable flexibility to give support to implied heterogeneity in cyber-physical systems. Quality of Service (QoS) and Quality of Control (QoC) parameters are commonly utilized to evaluate the efficiency of the communications and the control loop. Agents can use the quality measures to take a wide range of decisions, like suitable placement on the control node or to change the workload to save energy. This article describes the architecture of a multi agent system that provides support to QoS and QoC parameters to optimize de system. The architecture uses a Publish-Subscriber model, based on Data Distribution Service (DDS) to send the control messages. Due to the nature of the Publish-Subscribe model, the architecture is suitable to implement event-based control (EBC) systems. The architecture has been called FSACtrl.

On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks.

PubMed

Monowar, Muhammad Mostafa; Bajaber, Fuad

2015-06-15

In this paper, we address the thermal rise and Quality-of-Service (QoS) provisioning issue for an intra-body Wireless Body Area Network (WBAN) having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s), and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches.

On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks

PubMed Central

Monowar, Muhammad Mostafa; Bajaber, Fuad

2015-01-01

In this paper, we address the thermal rise and Quality-of-Service (QoS) provisioning issue for an intra-body Wireless Body Area Network (WBAN) having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s), and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches. PMID:26083228

A Near-Optimal Distributed QoS Constrained Routing Algorithm for Multichannel Wireless Sensor Networks

PubMed Central

Lin, Frank Yeong-Sung; Hsiao, Chiu-Han; Yen, Hong-Hsu; Hsieh, Yu-Jen

2013-01-01

One of the important applications in Wireless Sensor Networks (WSNs) is video surveillance that includes the tasks of video data processing and transmission. Processing and transmission of image and video data in WSNs has attracted a lot of attention in recent years. This is known as Wireless Visual Sensor Networks (WVSNs). WVSNs are distributed intelligent systems for collecting image or video data with unique performance, complexity, and quality of service challenges. WVSNs consist of a large number of battery-powered and resource constrained camera nodes. End-to-end delay is a very important Quality of Service (QoS) metric for video surveillance application in WVSNs. How to meet the stringent delay QoS in resource constrained WVSNs is a challenging issue that requires novel distributed and collaborative routing strategies. This paper proposes a Near-Optimal Distributed QoS Constrained (NODQC) routing algorithm to achieve an end-to-end route with lower delay and higher throughput. A Lagrangian Relaxation (LR)-based routing metric that considers the “system perspective” and “user perspective” is proposed to determine the near-optimal routing paths that satisfy end-to-end delay constraints with high system throughput. The empirical results show that the NODQC routing algorithm outperforms others in terms of higher system throughput with lower average end-to-end delay and delay jitter. In this paper, for the first time, the algorithm shows how to meet the delay QoS and at the same time how to achieve higher system throughput in stringently resource constrained WVSNs.

Alleviating Bandwidth Constraints by Implementing Quality of Service on Teleport Site Connections

DTIC Science & Technology

2008-02-19

adequate 1 SkillSoft, "Implementing Quality of Service," DISA eLearning Portal, <https://hr.disa.mil...training/ elearning /index.html> (19 February 2008), QoS overview. Cited hereafter as Skillsoft. 4 bandwidth, the router’s QoS mechanism is passive...nation’s warfighter. Hence, he tasked DISA to create Net- Centric Implementation Documents (NCID) that relate Global

Trust-Enhanced Cloud Service Selection Model Based on QoS Analysis.

PubMed

Pan, Yuchen; Ding, Shuai; Fan, Wenjuan; Li, Jing; Yang, Shanlin

2015-01-01

Cloud computing technology plays a very important role in many areas, such as in the construction and development of the smart city. Meanwhile, numerous cloud services appear on the cloud-based platform. Therefore how to how to select trustworthy cloud services remains a significant problem in such platforms, and extensively investigated owing to the ever-growing needs of users. However, trust relationship in social network has not been taken into account in existing methods of cloud service selection and recommendation. In this paper, we propose a cloud service selection model based on the trust-enhanced similarity. Firstly, the direct, indirect, and hybrid trust degrees are measured based on the interaction frequencies among users. Secondly, we estimate the overall similarity by combining the experience usability measured based on Jaccard's Coefficient and the numerical distance computed by Pearson Correlation Coefficient. Then through using the trust degree to modify the basic similarity, we obtain a trust-enhanced similarity. Finally, we utilize the trust-enhanced similarity to find similar trusted neighbors and predict the missing QoS values as the basis of cloud service selection and recommendation. The experimental results show that our approach is able to obtain optimal results via adjusting parameters and exhibits high effectiveness. The cloud services ranking by our model also have better QoS properties than other methods in the comparison experiments.

Trust-Enhanced Cloud Service Selection Model Based on QoS Analysis

PubMed Central

Pan, Yuchen; Ding, Shuai; Fan, Wenjuan; Li, Jing; Yang, Shanlin

2015-01-01

Cloud computing technology plays a very important role in many areas, such as in the construction and development of the smart city. Meanwhile, numerous cloud services appear on the cloud-based platform. Therefore how to how to select trustworthy cloud services remains a significant problem in such platforms, and extensively investigated owing to the ever-growing needs of users. However, trust relationship in social network has not been taken into account in existing methods of cloud service selection and recommendation. In this paper, we propose a cloud service selection model based on the trust-enhanced similarity. Firstly, the direct, indirect, and hybrid trust degrees are measured based on the interaction frequencies among users. Secondly, we estimate the overall similarity by combining the experience usability measured based on Jaccard’s Coefficient and the numerical distance computed by Pearson Correlation Coefficient. Then through using the trust degree to modify the basic similarity, we obtain a trust-enhanced similarity. Finally, we utilize the trust-enhanced similarity to find similar trusted neighbors and predict the missing QoS values as the basis of cloud service selection and recommendation. The experimental results show that our approach is able to obtain optimal results via adjusting parameters and exhibits high effectiveness. The cloud services ranking by our model also have better QoS properties than other methods in the comparison experiments. PMID:26606388

Service models and realization of differentiated services networks

NASA Astrophysics Data System (ADS)

Elizondo, Antonio J.; Garcia Osma, Maria L.; Einsiedler, Hans J.; Roth, Rudolf; Smirnov, Michael I.; Bartoli, Maurizio; Castelli, Paolo; Varga, Balazs; Krampell, Magnus

2001-07-01

Internet Service Providers need to offer Quality of Service (QoS) to fulfil the requirements of applications of their customers. Moreover, in a competitive market environment costs must be low. The selected service model must be effective and low in complexity, but it should still provide high quality and service differentiation, that the current Internet is not yet capable to support. The Differentiated Services (DiffServ) Architecture has been proposed for enabling a range of different Classes of Service (CoS). In the EURESCOM project P1006 several European service providers co-operated to examine various aspects involved in the introduction of service differentiation using the DiffServ approach. The project explored a set of service models for Expedited Forwarding (EF) and Assured Forwarding (AF) and identified requirements for network nodes. Besides, we addressed also measurement issues, charging and accounting issues. Special attention has been devoted to requirements of elastic traffic that adapts its sending rate to congestion state and available bandwidth. QoS mechanisms must prove Transmission Control Protocol (TCP) friendliness. TCP performance degrades under multiple losses. Since RED based queue management may still cause multiple discards, a modified marking scheme called Capped Leaky Bucket is proposed to improve the performance of elastic applications.

TinyOS-based quality of service management in wireless sensor networks

USGS Publications Warehouse

Peterson, N.; Anusuya-Rangappa, L.; Shirazi, B.A.; Huang, R.; Song, W.-Z.; Miceli, M.; McBride, D.; Hurson, A.; LaHusen, R.

2009-01-01

Previously the cost and extremely limited capabilities of sensors prohibited Quality of Service (QoS) implementations in wireless sensor networks. With advances in technology, sensors are becoming significantly less expensive and the increases in computational and storage capabilities are opening the door for new, sophisticated algorithms to be implemented. Newer sensor network applications require higher data rates with more stringent priority requirements. We introduce a dynamic scheduling algorithm to improve bandwidth for high priority data in sensor networks, called Tiny-DWFQ. Our Tiny-Dynamic Weighted Fair Queuing scheduling algorithm allows for dynamic QoS for prioritized communications by continually adjusting the treatment of communication packages according to their priorities and the current level of network congestion. For performance evaluation, we tested Tiny-DWFQ, Tiny-WFQ (traditional WFQ algorithm implemented in TinyOS), and FIFO queues on an Imote2-based wireless sensor network and report their throughput and packet loss. Our results show that Tiny-DWFQ performs better in all test cases. ?? 2009 IEEE.

Enhancing the Quality of Service for Real Time Traffic over Optical Burst Switching (OBS) Networks with Ensuring the Fairness for Other Traffics.

PubMed

Al-Shargabi, Mohammed A; Shaikh, Asadullah; Ismail, Abdulsamad S

2016-01-01

Optical burst switching (OBS) networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS) for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS' QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR) scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate) ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50-60%, 30-40%, and 10-20% for high, normal, and low traffic loads respectively.

Enhancing the Quality of Service for Real Time Traffic over Optical Burst Switching (OBS) Networks with Ensuring the Fairness for Other Traffics

PubMed Central

Al-Shargabi, Mohammed A.; Ismail, Abdulsamad S.

2016-01-01

Optical burst switching (OBS) networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS) for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS’ QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR) scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate) ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50–60%, 30–40%, and 10–20% for high, normal, and low traffic loads respectively. PMID:27583557

An Adaptive Failure Detector Based on Quality of Service in Peer-to-Peer Networks

PubMed Central

Dong, Jian; Ren, Xiao; Zuo, Decheng; Liu, Hongwei

2014-01-01

The failure detector is one of the fundamental components that maintain high availability of Peer-to-Peer (P2P) networks. Under different network conditions, the adaptive failure detector based on quality of service (QoS) can achieve the detection time and accuracy required by upper applications with lower detection overhead. In P2P systems, complexity of network and high churn lead to high message loss rate. To reduce the impact on detection accuracy, baseline detection strategy based on retransmission mechanism has been employed widely in many P2P applications; however, Chen's classic adaptive model cannot describe this kind of detection strategy. In order to provide an efficient service of failure detection in P2P systems, this paper establishes a novel QoS evaluation model for the baseline detection strategy. The relationship between the detection period and the QoS is discussed and on this basis, an adaptive failure detector (B-AFD) is proposed, which can meet the quantitative QoS metrics under changing network environment. Meanwhile, it is observed from the experimental analysis that B-AFD achieves better detection accuracy and time with lower detection overhead compared to the traditional baseline strategy and the adaptive detectors based on Chen's model. Moreover, B-AFD has better adaptability to P2P network. PMID:25198005

QoS for Real Time Applications over Next Generation Data Networks

NASA Technical Reports Server (NTRS)

Ivancic, William; Atiquzzaman, Mohammed; Bai, Haowei; Su, Hongjun; Chitri, Jyotsna; Ahamed, Faruque

2001-01-01

Viewgraphs on Qualtity of Service (QOS) for real time applications over next generation data networks are presented. The progress to date include: Task 1: QoS in Integrated Services over DiffServ networks (UD); Task 2: Interconnecting ATN with the next generation Internet (UD); Task 3: QoS in DiffServ over ATM (UD); Task 4: Improving Explicit Congestion Notification with the Mark-Front Strategy (OSU); Task 5: Multiplexing VBR over VBR (OSU); and Task 6: Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services (OSU).

An initial approach towards quality of service based Spectrum Trading

NASA Astrophysics Data System (ADS)

Bastidas, Carlos E. Caicedo; Vanhoy, Garret; Volos, Haris I.; Bose, Tamal

Spectrum scarcity has become an important issue as demands for higher data rates increase in diverse wireless applications and aerospace communication scenarios. To address this problem, it becomes necessary to manage radio spectrum assignment in a way that optimizes the distribution of spectrum resources among several users while taking into account the quality of service (QoS) characteristics desired by the users of spectrum. In this paper, a novel approach to managing spectrum assignment based on Spectrum Trading (ST) will be presented. Market based spectrum assignment mechanisms such as spectrum trading are of growing interest to many spectrum management agencies that are planning to increase the use of these mechanisms for spectrum management and reduce their emphasis on command and control methods. This paper presents some of our initial work into incorporating quality of service information into the mechanisms that determine how spectrum should be traded when using a spectrum exchange. Through simulations and a testbed implementation of a QoS aware spectrum exchange our results show the viability of using QoS based mechanisms in spectrum trading and in the enhancement of dynamic spectrum assignment systems.

A QoS scheme for a congestion core network based on dissimilar QoS structures in smart-phone environments.

PubMed

Hong, Sung-Ryong; Na, Wonshik; Kang, Jang-Mook

2010-01-01

This study suggests an approach to effective transmission of multimedia content in a rapidly changing Internet environment including smart-phones. Guaranteeing QoS in networks is currently an important research topic. When transmitting Assured Forwarding (AF) packets in a Multi-DiffServ network environment, network A may assign priority in an order AF1, AF2, AF3 and AF4; on the other hand, network B may reverse the order to a priority AF4, AF3, AF2 and AF1. In this case, the AF1 packets that received the best quality of service in network A will receive the lowest in network B, which may result in dropping of packets in network B and vice versa. This study suggests a way to guarantee QoS between hosts by minimizing the loss of AF packet class when one network transmits AF class packets to another network with differing principles. It is expected that QoS guarantees and their experimental value may be utilized as principles which can be applied to various mobile-web environments based on smart-phones.

A QoS Scheme for a Congestion Core Network Based on Dissimilar QoS Structures in Smart-Phone Environments

PubMed Central

Hong, Sung-Ryong; Na, Wonshik; Kang, Jang-Mook

2010-01-01

This study suggests an approach to effective transmission of multimedia content in a rapidly changing Internet environment including smart-phones. Guaranteeing QoS in networks is currently an important research topic. When transmitting Assured Forwarding (AF) packets in a Multi-DiffServ network environment, network A may assign priority in an order AF1, AF2, AF3 and AF4; on the other hand, network B may reverse the order to a priority AF4, AF3, AF2 and AF1. In this case, the AF1 packets that received the best quality of service in network A will receive the lowest in network B, which may result in dropping of packets in network B and vice versa. This study suggests a way to guarantee QoS between hosts by minimizing the loss of AF packet class when one network transmits AF class packets to another network with differing principles. It is expected that QoS guarantees and their experimental value may be utilized as principles which can be applied to various mobile-web environments based on smart-phones. PMID:22163453

Impact of the codec and various QoS methods on the final quality of the transferred voice in an IP network

NASA Astrophysics Data System (ADS)

Slavata, Oldřich; Holub, Jan

2015-02-01

This paper deals with an analysis of the relation between the codec that is used, the QoS method, and the final voice transmission quality. The Cisco 2811 router is used for adjusting QoS. VoIP client Linphone is used for adjusting the codec. The criterion for transmission quality is the MOS parameter investigated with the ITU-T P.862 PESQ and P.863 POLQA algorithms.

Providing end-to-end QoS for multimedia applications in 3G wireless networks

NASA Astrophysics Data System (ADS)

Guo, Katherine; Rangarajan, Samapth; Siddiqui, M. A.; Paul, Sanjoy

2003-11-01

As the usage of wireless packet data services increases, wireless carriers today are faced with the challenge of offering multimedia applications with QoS requirements within current 3G data networks. End-to-end QoS requires support at the application, network, link and medium access control (MAC) layers. We discuss existing CDMA2000 network architecture and show its shortcomings that prevent supporting multiple classes of traffic at the Radio Access Network (RAN). We then propose changes in RAN within the standards framework that enable support for multiple traffic classes. In addition, we discuss how Session Initiation Protocol (SIP) can be augmented with QoS signaling for supporting end-to-end QoS. We also review state of the art scheduling algorithms at the base station and provide possible extensions to these algorithms to support different classes of traffic as well as different classes of users.

Cross-layer protocol design for QoS optimization in real-time wireless sensor networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2010-04-01

The metrics of quality of service (QoS) for each sensor type in a wireless sensor network can be associated with metrics for multimedia that describe the quality of fused information, e.g., throughput, delay, jitter, packet error rate, information correlation, etc. These QoS metrics are typically set at the highest, or application, layer of the protocol stack to ensure that performance requirements for each type of sensor data are satisfied. Application-layer metrics, in turn, depend on the support of the lower protocol layers: session, transport, network, data link (MAC), and physical. The dependencies of the QoS metrics on the performance of the higher layers of the Open System Interconnection (OSI) reference model of the WSN protocol, together with that of the lower three layers, are the basis for a comprehensive approach to QoS optimization for multiple sensor types in a general WSN model. The cross-layer design accounts for the distributed power consumption along energy-constrained routes and their constituent nodes. Following the author's previous work, the cross-layer interactions in the WSN protocol are represented by a set of concatenated protocol parameters and enabling resource levels. The "best" cross-layer designs to achieve optimal QoS are established by applying the general theory of martingale representations to the parameterized multivariate point processes (MVPPs) for discrete random events occurring in the WSN. Adaptive control of network behavior through the cross-layer design is realized through the parametric factorization of the stochastic conditional rates of the MVPPs. The cross-layer protocol parameters for optimal QoS are determined in terms of solutions to stochastic dynamic programming conditions derived from models of transient flows for heterogeneous sensor data and aggregate information over a finite time horizon. Markov state processes, embedded within the complex combinatorial history of WSN events, are more computationally

Quality of Service in Networks Supporting Cultural Multimedia Applications

ERIC Educational Resources Information Center

Kanellopoulos, Dimitris N.

2011-01-01

Purpose: This paper aims to provide an overview of representative multimedia applications in the cultural heritage sector, as well as research results on quality of service (QoS) mechanisms in internet protocol (IP) networks that support such applications. Design/methodology/approach: The paper's approach is a literature review. Findings: Cultural…

Quality of service and customer satisfaction on arterial streets : final report

DOT National Transportation Integrated Search

2003-06-13

This report presents the results of a qualitative study of driver perception of quality of service (QOS) on urban arterial streets. The purpose of the study was to identify the factors that are important to drivers of personal automobiles (non-commer...

Providing QoS through machine-learning-driven adaptive multimedia applications.

PubMed

Ruiz, Pedro M; Botía, Juan A; Gómez-Skarmeta, Antonio

2004-06-01

We investigate the optimization of the quality of service (QoS) offered by real-time multimedia adaptive applications through machine learning algorithms. These applications are able to adapt in real time their internal settings (i.e., video sizes, audio and video codecs, among others) to the unpredictably changing capacity of the network. Traditional adaptive applications just select a set of settings to consume less than the available bandwidth. We propose a novel approach in which the selected set of settings is the one which offers a better user-perceived QoS among all those combinations which satisfy the bandwidth restrictions. We use a genetic algorithm to decide when to trigger the adaptation process depending on the network conditions (i.e., loss-rate, jitter, etc.). Additionally, the selection of the new set of settings is done according to a set of rules which model the user-perceived QoS. These rules are learned using the SLIPPER rule induction algorithm over a set of examples extracted from scores provided by real users. We will demonstrate that the proposed approach guarantees a good user-perceived QoS even when the network conditions are constantly changing.

A Study of Quality of Service Communication for High-Speed Packet-Switching Computer Sub-Networks

NASA Technical Reports Server (NTRS)

Cui, Zhenqian

1999-01-01

In this thesis, we analyze various factors that affect quality of service (QoS) communication in high-speed, packet-switching sub-networks. We hypothesize that sub-network-wide bandwidth reservation and guaranteed CPU processing power at endpoint systems for handling data traffic are indispensable to achieving hard end-to-end quality of service. Different bandwidth reservation strategies, traffic characterization schemes, and scheduling algorithms affect the network resources and CPU usage as well as the extent that QoS can be achieved. In order to analyze those factors, we design and implement a communication layer. Our experimental analysis supports our research hypothesis. The Resource ReSerVation Protocol (RSVP) is designed to realize resource reservation. Our analysis of RSVP shows that using RSVP solely is insufficient to provide hard end-to-end quality of service in a high-speed sub-network. Analysis of the IEEE 802.lp protocol also supports the research hypothesis.

IP access networks with QoS support

NASA Astrophysics Data System (ADS)

Sargento, Susana; Valadas, Rui J. M. T.; Goncalves, Jorge; Sousa, Henrique

2001-07-01

The increasing demand of new services and applications is pushing for drastic changes on the design of access networks targeted mainly for residential and SOHO users. Future access networks will provide full service integration (including multimedia), resource sharing at the packet level and QoS support. It is expected that using IP as the base technology, the ideal plug-and-play scenario, where the management actions of the access network operator are kept to a minimum, will be achieved easily. This paper proposes an architecture for access networks based on layer 2 or layer 3 multiplexers that allows a number of simplifications in the network elements and protocols (e.g. in the routing and addressing functions). We discuss two possible steps in the evolution of access networks towards a more efficient support of IP based services. The first one still provides no QoS support and was designed with the goal of reusing as much as possible current technologies; it is based on tunneling to transport PPP sessions. The second one introduces QoS support through the use of emerging technologies and protocols. We illustrate the different phases of a multimedia Internet access session, when using SIP for session initiation, COPS for the management of QoS policies including the AAA functions and RSVP for resource reservation.

Dynamic Policy-Driven Quality of Service in Service-Oriented Information Management Systems

DTIC Science & Technology

2011-01-01

both DiffServ and IntServ net- work QoS mechanisms. Wang et al [48] provide middleware APIs to shield applications from directly interacting with...complex network QoS mechanism APIs . Middleware frameworks transparently converted the specified application QoS requirements into low- er-level network...QoS mechanism APIs and provided network QoS assurances. Deployment-time resource allocation. Other prior work has focused on deploying ap- plications

Adaptation of Collaborative Applications for Network Quality Variation

DTIC Science & Technology

2004-06-01

collaborative application. 1.1 Quality of Service Quality of Service (QoS) is generally regarded as an end-to-end network application...using the Cloud WAN Emulator [14]. We used qtcp1 to measure end-to-end network service quality between the signal sender and the signal receiver. The...application must be aware of current resource 1 Qtcp measures end-to-end network integrity and service quality for QoS verification. Qtcp sends a

A Control-Theoretic Approach for the Combined Management of Quality-of-Service and Energy in Service Centers

NASA Astrophysics Data System (ADS)

Poussot-Vassal, Charles; Tanelli, Mara; Lovera, Marco

The complexity of Information Technology (IT) systems is steadily increasing and system complexity has been recognised as the main obstacle to further advancements of IT. This fact has recently raised energy management issues. Control techniques have been proposed and successfully applied to design Autonomic Computing systems, trading-off system performance with energy saving goals. As users behaviour is highly time varying and workload conditions can change substantially within the same business day, the Linear Parametrically Varying (LPV) framework is particularly promising for modeling such systems. In this chapter, a control-theoretic method to investigate the trade-off between Quality of Service (QoS) requirements and energy saving objectives in the case of admission control in Web service systems is proposed, considering as control variables the server CPU frequency and the admission probability. To quantitatively evaluate the trade-off, a dynamic model of the admission control dynamics is estimated via LPV identification techniques. Based on this model, an optimisation problem within the Model Predictive Control (MPC) framework is setup, by means of which it is possible to investigate the optimal trade-off policy to manage QoS and energy saving objectives at design time and taking into explicit account the system dynamics.

Joint terminals and relay optimization for two-way power line information exchange systems with QoS constraints

NASA Astrophysics Data System (ADS)

Wu, Xiaolin; Rong, Yue

2015-12-01

The quality-of-service (QoS) criteria (measured in terms of the minimum capacity requirement in this paper) are very important to practical indoor power line communication (PLC) applications as they greatly affect the user experience. With a two-way multicarrier relay configuration, in this paper we investigate the joint terminals and relay power optimization for the indoor broadband PLC environment, where the relay node works in the amplify-and-forward (AF) mode. As the QoS-constrained power allocation problem is highly non-convex, the globally optimal solution is computationally intractable to obtain. To overcome this challenge, we propose an alternating optimization (AO) method to decompose this problem into three convex/quasi-convex sub-problems. Simulation results demonstrate the fast convergence of the proposed algorithm under practical PLC channel conditions. Compared with the conventional bidirectional direct transmission (BDT) system, the relay-assisted two-way information exchange (R2WX) scheme can meet the same QoS requirement with less total power consumption.

Survey on Monitoring and Quality Controlling of the Mobile Biosignal Delivery.

PubMed

Pawar, Pravin A; Edla, Damodar R; Edoh, Thierry; Shinde, Vijay; van Beijnum, Bert-Jan

2017-10-31

A Mobile Patient Monitoring System (MPMS) acquires patient's biosignals and transmits them using wireless network connection to the decision-making module or healthcare professional for the assessment of patient's condition. A variety of wireless network technologies such as wireless personal area networks (e.g., Bluetooth), mobile ad-hoc networks (MANET), and infrastructure-based networks (e.g., WLAN and cellular networks) are in practice for biosignals delivery. The wireless network quality-of-service (QoS) requirements of biosignals delivery are mainly specified in terms of required bandwidth, acceptable delay, and tolerable error rate. An important research challenge in the MPMS is how to satisfy QoS requirements of biosignals delivery in the environment characterized by patient mobility, deployment of multiple wireless network technologies, and variable QoS characteristics of the wireless networks. QoS requirements are mainly application specific, while available QoS is largely dependent on QoS provided by wireless network in use. QoS provisioning refers to providing support for improving QoS experience of networked applications. In resource poor conditions, application adaptation may also be required to make maximum use of available wireless network QoS. This survey paper presents a survey of recent developments in the area of QoS provisioning for MPMS. In particular, our contributions are as follows: (1) overview of wireless networks and network QoS requirements of biosignals delivery; (2) survey of wireless networks' QoS performance evaluation for the transmission of biosignals; and (3) survey of QoS provisioning mechanisms for biosignals delivery in MPMS. We also propose integrating end-to-end QoS monitoring and QoS provisioning strategies in a mobile patient monitoring system infrastructure to support optimal delivery of biosignals to the healthcare professionals.

Adaptive Traffic Route Control in QoS Provisioning for Cognitive Radio Technology with Heterogeneous Wireless Systems

NASA Astrophysics Data System (ADS)

Yamamoto, Toshiaki; Ueda, Tetsuro; Obana, Sadao

As one of the dynamic spectrum access technologies, “cognitive radio technology,” which aims to improve the spectrum efficiency, has been studied. In cognitive radio networks, each node recognizes radio conditions, and according to them, optimizes its wireless communication routes. Cognitive radio systems integrate the heterogeneous wireless systems not only by switching over them but also aggregating and utilizing them simultaneously. The adaptive control of switchover use and concurrent use of various wireless systems will offer a stable and flexible wireless communication. In this paper, we propose the adaptive traffic route control scheme that provides high quality of service (QoS) for cognitive radio technology, and examine the performance of the proposed scheme through the field trials and computer simulations. The results of field trials show that the adaptive route control according to the radio conditions improves the user IP throughput by more than 20% and reduce the one-way delay to less than 1/6 with the concurrent use of IEEE802.16 and IEEE802.11 wireless media. Moreover, the simulation results assuming hundreds of mobile terminals reveal that the number of users receiving the required QoS of voice over IP (VoIP) service and the total network throughput of FTP users increase by more than twice at the same time with the proposed algorithm. The proposed adaptive traffic route control scheme can enhance the performances of the cognitive radio technologies by providing the appropriate communication routes for various applications to satisfy their required QoS.

Time-Aware Service Ranking Prediction in the Internet of Things Environment

PubMed Central

Huang, Yuze; Huang, Jiwei; Cheng, Bo; He, Shuqing; Chen, Junliang

2017-01-01

With the rapid development of the Internet of things (IoT), building IoT systems with high quality of service (QoS) has become an urgent requirement in both academia and industry. During the procedures of building IoT systems, QoS-aware service selection is an important concern, which requires the ranking of a set of functionally similar services according to their QoS values. In reality, however, it is quite expensive and even impractical to evaluate all geographically-dispersed IoT services at a single client to obtain such a ranking. Nevertheless, distributed measurement and ranking aggregation have to deal with the high dynamics of QoS values and the inconsistency of partial rankings. To address these challenges, we propose a time-aware service ranking prediction approach named TSRPred for obtaining the global ranking from the collection of partial rankings. Specifically, a pairwise comparison model is constructed to describe the relationships between different services, where the partial rankings are obtained by time series forecasting on QoS values. The comparisons of IoT services are formulated by random walks, and thus, the global ranking can be obtained by sorting the steady-state probabilities of the underlying Markov chain. Finally, the efficacy of TSRPred is validated by simulation experiments based on large-scale real-world datasets. PMID:28448451

Time-Aware Service Ranking Prediction in the Internet of Things Environment.

PubMed

Huang, Yuze; Huang, Jiwei; Cheng, Bo; He, Shuqing; Chen, Junliang

2017-04-27

With the rapid development of the Internet of things (IoT), building IoT systems with high quality of service (QoS) has become an urgent requirement in both academia and industry. During the procedures of building IoT systems, QoS-aware service selection is an important concern, which requires the ranking of a set of functionally similar services according to their QoS values. In reality, however, it is quite expensive and even impractical to evaluate all geographically-dispersed IoT services at a single client to obtain such a ranking. Nevertheless, distributed measurement and ranking aggregation have to deal with the high dynamics of QoS values and the inconsistency of partial rankings. To address these challenges, we propose a time-aware service ranking prediction approach named TSRPred for obtaining the global ranking from the collection of partial rankings. Specifically, a pairwise comparison model is constructed to describe the relationships between different services, where the partial rankings are obtained by time series forecasting on QoS values. The comparisons of IoT services are formulated by random walks, and thus, the global ranking can be obtained by sorting the steady-state probabilities of the underlying Markov chain. Finally, the efficacy of TSRPred is validated by simulation experiments based on large-scale real-world datasets.

Internet technologies and requirements for telemedicine

NASA Technical Reports Server (NTRS)

Lamaster, H.; Meylor, J.; Meylor, F.

1997-01-01

Internet technologies are briefly introduced and those applicable for telemedicine are reviewed. Multicast internet technologies are described. The National Aeronautics and Space Administration (NASA) 'Telemedicine Space-bridge to Russia' project is described and used to derive requirements for internet telemedicine. Telemedicine privacy and Quality of Service (QoS) requirements are described.

Two-dimensional priority-based dynamic resource allocation algorithm for QoS in WDM/TDM PON networks

NASA Astrophysics Data System (ADS)

Sun, Yixin; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Rao, Lan

2018-01-01

Wavelength division multiplexing/time division multiplexing (WDM/TDM) passive optical networks (PON) is being viewed as a promising solution for delivering multiple services and applications. The hybrid WDM / TDM PON uses the wavelength and bandwidth allocation strategy to control the distribution of the wavelength channels in the uplink direction, so that it can ensure the high bandwidth requirements of multiple Optical Network Units (ONUs) while improving the wavelength resource utilization. Through the investigation of the presented dynamic bandwidth allocation algorithms, these algorithms can't satisfy the requirements of different levels of service very well while adapting to the structural characteristics of mixed WDM / TDM PON system. This paper introduces a novel wavelength and bandwidth allocation algorithm to efficiently utilize the bandwidth and support QoS (Quality of Service) guarantees in WDM/TDM PON. Two priority based polling subcycles are introduced in order to increase system efficiency and improve system performance. The fixed priority polling subcycle and dynamic priority polling subcycle follow different principles to implement wavelength and bandwidth allocation according to the priority of different levels of service. A simulation was conducted to study the performance of the priority based polling in dynamic resource allocation algorithm in WDM/TDM PON. The results show that the performance of delay-sensitive services is greatly improved without degrading QoS guarantees for other services. Compared with the traditional dynamic bandwidth allocation algorithms, this algorithm can meet bandwidth needs of different priority traffic class, achieve low loss rate performance, and ensure real-time of high priority traffic class in terms of overall traffic on the network.

Real-Time QoS Routing Protocols in Wireless Multimedia Sensor Networks: Study and Analysis.

PubMed

Alanazi, Adwan; Elleithy, Khaled

2015-09-02

Many routing protocols have been proposed for wireless sensor networks. These routing protocols are almost always based on energy efficiency. However, recent advances in complementary metal-oxide semiconductor (CMOS) cameras and small microphones have led to the development of Wireless Multimedia Sensor Networks (WMSN) as a class of wireless sensor networks which pose additional challenges. The transmission of imaging and video data needs routing protocols with both energy efficiency and Quality of Service (QoS) characteristics in order to guarantee the efficient use of the sensor nodes and effective access to the collected data. Also, with integration of real time applications in Wireless Senor Networks (WSNs), the use of QoS routing protocols is not only becoming a significant topic, but is also gaining the attention of researchers. In designing an efficient QoS routing protocol, the reliability and guarantee of end-to-end delay are critical events while conserving energy. Thus, considerable research has been focused on designing energy efficient and robust QoS routing protocols. In this paper, we present a state of the art research work based on real-time QoS routing protocols for WMSNs that have already been proposed. This paper categorizes the real-time QoS routing protocols into probabilistic and deterministic protocols. In addition, both categories are classified into soft and hard real time protocols by highlighting the QoS issues including the limitations and features of each protocol. Furthermore, we have compared the performance of mobility-aware query based real-time QoS routing protocols from each category using Network Simulator-2 (NS2). This paper also focuses on the design challenges and future research directions as well as highlights the characteristics of each QoS routing protocol.

Real-Time QoS Routing Protocols in Wireless Multimedia Sensor Networks: Study and Analysis

PubMed Central

Alanazi, Adwan; Elleithy, Khaled

2015-01-01

Many routing protocols have been proposed for wireless sensor networks. These routing protocols are almost always based on energy efficiency. However, recent advances in complementary metal-oxide semiconductor (CMOS) cameras and small microphones have led to the development of Wireless Multimedia Sensor Networks (WMSN) as a class of wireless sensor networks which pose additional challenges. The transmission of imaging and video data needs routing protocols with both energy efficiency and Quality of Service (QoS) characteristics in order to guarantee the efficient use of the sensor nodes and effective access to the collected data. Also, with integration of real time applications in Wireless Senor Networks (WSNs), the use of QoS routing protocols is not only becoming a significant topic, but is also gaining the attention of researchers. In designing an efficient QoS routing protocol, the reliability and guarantee of end-to-end delay are critical events while conserving energy. Thus, considerable research has been focused on designing energy efficient and robust QoS routing protocols. In this paper, we present a state of the art research work based on real-time QoS routing protocols for WMSNs that have already been proposed. This paper categorizes the real-time QoS routing protocols into probabilistic and deterministic protocols. In addition, both categories are classified into soft and hard real time protocols by highlighting the QoS issues including the limitations and features of each protocol. Furthermore, we have compared the performance of mobility-aware query based real-time QoS routing protocols from each category using Network Simulator-2 (NS2). This paper also focuses on the design challenges and future research directions as well as highlights the characteristics of each QoS routing protocol. PMID:26364639

Efficiently Selecting the Best Web Services

NASA Astrophysics Data System (ADS)

Goncalves, Marlene; Vidal, Maria-Esther; Regalado, Alfredo; Yacoubi Ayadi, Nadia

Emerging technologies and linking data initiatives have motivated the publication of a large number of datasets, and provide the basis for publishing Web services and tools to manage the available data. This wealth of resources opens a world of possibilities to satisfy user requests. However, Web services may have similar functionality and assess different performance; therefore, it is required to identify among the Web services that satisfy a user request, the ones with the best quality. In this paper we propose a hybrid approach that combines reasoning tasks with ranking techniques to aim at the selection of the Web services that best implement a user request. Web service functionalities are described in terms of input and output attributes annotated with existing ontologies, non-functionality is represented as Quality of Services (QoS) parameters, and user requests correspond to conjunctive queries whose sub-goals impose restrictions on the functionality and quality of the services to be selected. The ontology annotations are used in different reasoning tasks to infer service implicit properties and to augment the size of the service search space. Furthermore, QoS parameters are considered by a ranking metric to classify the services according to how well they meet a user non-functional condition. We assume that all the QoS parameters of the non-functional condition are equally important, and apply the Top-k Skyline approach to select the k services that best meet this condition. Our proposal relies on a two-fold solution which fires a deductive-based engine that performs different reasoning tasks to discover the services that satisfy the requested functionality, and an efficient implementation of the Top-k Skyline approach to compute the top-k services that meet the majority of the QoS constraints. Our Top-k Skyline solution exploits the properties of the Skyline Frequency metric and identifies the top-k services by just analyzing a subset of the services that

Fuzzy Logic-based Intelligent Scheme for Enhancing QoS of Vertical Handover Decision in Vehicular Ad-hoc Networks

NASA Astrophysics Data System (ADS)

Azzali, F.; Ghazali, O.; Omar, M. H.

2017-08-01

The design of next generation networks in various technologies under the “Anywhere, Anytime” paradigm offers seamless connectivity across different coverage. A conventional algorithm such as RSSThreshold algorithm, that only uses the received strength signal (RSS) as a metric, will decrease handover performance regarding handover latency, delay, packet loss, and handover failure probability. Moreover, the RSS-based algorithm is only suitable for horizontal handover decision to examine the quality of service (QoS) compared to the vertical handover decision in advanced technologies. In the next generation network, vertical handover can be started based on the user’s convenience or choice rather than connectivity reasons. This study proposes a vertical handover decision algorithm that uses a Fuzzy Logic (FL) algorithm, to increase QoS performance in heterogeneous vehicular ad-hoc networks (VANET). The study uses network simulator 2.29 (NS 2.29) along with the mobility traffic network and generator to implement simulation scenarios and topologies. This helps the simulation to achieve a realistic VANET mobility scenario. The required analysis on the performance of QoS in the vertical handover can thus be conducted. The proposed Fuzzy Logic algorithm shows improvement over the conventional algorithm (RSSThreshold) in the average percentage of handover QoS whereby it achieves 20%, 21% and 13% improvement on handover latency, delay, and packet loss respectively. This is achieved through triggering a process in layer two and three that enhances the handover performance.

Modeling and Negotiating Service Quality

NASA Astrophysics Data System (ADS)

Benbernou, Salima; Brandic, Ivona; Cappiello, Cinzia; Carro, Manuel; Comuzzi, Marco; Kertész, Attila; Kritikos, Kyriakos; Parkin, Michael; Pernici, Barbara; Plebani, Pierluigi

In this chapter the research problems of specifying and negotiating QoS and its corresponding quality documents are analyzed. For this reason, this chapter is separated into two main sections, Section 6.1 and 6.2, with each dedicated to one of the two problems, i.e., QoS specification and negotiation, respectively. Each section has a similar structure: they first introduce the problem and then, in the remaining subsections, review related work. Finally, the chapter ends with Section 6.3, which identifies research gaps and presents potential research challenges in QoS modelling, specification and negotiation.

QoS Differential Scheduling in Cognitive-Radio-Based Smart Grid Networks: An Adaptive Dynamic Programming Approach.

PubMed

Yu, Rong; Zhong, Weifeng; Xie, Shengli; Zhang, Yan; Zhang, Yun

2016-02-01

As the next-generation power grid, smart grid will be integrated with a variety of novel communication technologies to support the explosive data traffic and the diverse requirements of quality of service (QoS). Cognitive radio (CR), which has the favorable ability to improve the spectrum utilization, provides an efficient and reliable solution for smart grid communications networks. In this paper, we study the QoS differential scheduling problem in the CR-based smart grid communications networks. The scheduler is responsible for managing the spectrum resources and arranging the data transmissions of smart grid users (SGUs). To guarantee the differential QoS, the SGUs are assigned to have different priorities according to their roles and their current situations in the smart grid. Based on the QoS-aware priority policy, the scheduler adjusts the channels allocation to minimize the transmission delay of SGUs. The entire transmission scheduling problem is formulated as a semi-Markov decision process and solved by the methodology of adaptive dynamic programming. A heuristic dynamic programming (HDP) architecture is established for the scheduling problem. By the online network training, the HDP can learn from the activities of primary users and SGUs, and adjust the scheduling decision to achieve the purpose of transmission delay minimization. Simulation results illustrate that the proposed priority policy ensures the low transmission delay of high priority SGUs. In addition, the emergency data transmission delay is also reduced to a significantly low level, guaranteeing the differential QoS in smart grid.

CCSDS Time-Critical Onboard Networking Service

NASA Technical Reports Server (NTRS)

Parkes, Steve; Schnurr, Rick; Marquart, Jane; Menke, Greg; Ciccone, Massimiliano

2006-01-01

The Consultative Committee for Space Data Systems (CCSDS) is developing recommendations for communication services onboard spacecraft. Today many different communication buses are used on spacecraft requiring software with the same basic functionality to be rewritten for each type of bus. This impacts on the application software resulting in custom software for almost every new mission. The Spacecraft Onboard Interface Services (SOIS) working group aims to provide a consistent interface to various onboard buses and sub-networks, enabling a common interface to the application software. The eventual goal is reusable software that can be easily ported to new missions and run on a range of onboard buses without substantial modification. The system engineer will then be able to select a bus based on its performance, power, etc and be confident that a particular choice of bus will not place excessive demands on software development. This paper describes the SOIS Intra-Networking Service which is designed to enable data transfer and multiplexing of a variety of internetworking protocols with a range of quality of service support, over underlying heterogeneous data links. The Intra-network service interface provides users with a common Quality of Service interface when transporting data across a variety of underlying data links. Supported Quality of Service (QoS) elements include: Priority, Resource Reservation and Retry/Redundancy. These three QoS elements combine and map into four TCONS services for onboard data communications: Best Effort, Assured, Reserved, and Guaranteed. Data to be transported is passed to the Intra-network service with a requested QoS. The requested QoS includes the type of service, priority and where appropriate, a channel identifier. The data is de-multiplexed, prioritized, and the required resources for transport are allocated. The data is then passed to the appropriate data link for transfer across the bus. The SOIS supported data links may

TD-LTE Wireless Private Network QoS Transmission Protection

NASA Astrophysics Data System (ADS)

Zhang, Jianming; Cheng, Chao; Wu, Zanhong

With the commencement of construction of the smart grid, the demand power business for reliability and security continues to improve, the reliability transmission of power TD-LTE Wireless Private Network are more and more attention. For TD-LTE power private network, it can provide different QoS services according to the user's business type, to protect the reliable transmission of business. This article describes in detail the AF module of PCC in the EPC network, specifically introduces set up AF module station and QoS mechanisms in the EPS load, fully considers the business characteristics of the special power network, establishing a suitable architecture for mapping QoS parameters, ensuring the implementation of each QoS business. Through using radio bearer management, we can achieve the reliable transmission of each business on physical channel.

Multiantenna Relay Beamforming Design for QoS Discrimination in Two-Way Relay Networks

PubMed Central

Xiong, Ke; Zhang, Yu; Li, Dandan; Zhong, Zhangdui

2013-01-01

This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two-way relay networks. The purpose is to keep legitimate two-way relay users exchange their information via a helping multiantenna relay with QoS guarantee while avoiding the exchanged information overhearing by unauthorized receiver. To this end, we propose a physical layer method, where the relay beamforming is jointly designed with artificial noise (AN) which is used to interfere in the unauthorized user's reception. We formulate the joint beamforming and AN (BFA) design into an optimization problem such that the received signal-to-interference-ratio (SINR) at the two legitimate users is over a predefined QoS threshold while limiting the received SINR at the unauthorized user which is under a certain secure threshold. The objective of the optimization problem is to seek the optimal AN and beamforming vectors to minimize the total power consumed by the relay node. Since the optimization problem is nonconvex, we solve it by using semidefinite program (SDP) relaxation. For comparison, we also study the optimal relay beamforming without using AN (BFO) under the same QoS discrimination constraints. Simulation results show that both the proposed BFA and BFO can achieve the QoS discrimination of the two-way transmission. However, the proposed BFA yields significant power savings and lower infeasible rates compared with the BFO method. PMID:24391459

Bidirectional QoS support for novelty detection applications based on hierarchical wireless sensor network model

NASA Astrophysics Data System (ADS)

Edwards, Mark; Hu, Fei; Kumar, Sunil

2004-10-01

The research on the Novelty Detection System (NDS) (called as VENUS) at the authors' universities has generated exciting results. For example, we can detect an abnormal behavior (such as cars thefts from the parking lot) from a series of video frames based on the cognitively motivated theory of habituation. In this paper, we would like to describe the implementation strategies of lower layer protocols for using large-scale Wireless Sensor Networks (WSN) to NDS with Quality-of-Service (QoS) support. Wireless data collection framework, consisting of small and low-power sensor nodes, provides an alternative mechanism to observe the physical world, by using various types of sensing capabilities that include images (and even videos using Panoptos), sound and basic physical measurements such as temperature. We do not want to lose any 'data query command' packets (in the downstream direction: sink-to-sensors) or have any bit-errors in them since they are so important to the whole sensor network. In the upstream direction (sensors-to-sink), we may tolerate the loss of some sensing data packets. But the 'interested' sensing flow should be assigned a higher priority in terms of multi-hop path choice, network bandwidth allocation, and sensing data packet generation frequency (we hope to generate more sensing data packet for that novel event in the specified network area). The focus of this paper is to investigate MAC-level Quality of Service (QoS) issue in Wireless Sensor Networks (WSN) for Novelty Detection applications. Although QoS has been widely studied in other types of networks including wired Internet, general ad hoc networks and mobile cellular networks, we argue that QoS in WSN has its own characteristics. In wired Internet, the main QoS parameters include delay, jitter and bandwidth. In mobile cellular networks, two most common QoS metrics are: handoff call dropping probability and new call blocking probability. Since the main task of WSN is to detect and report

An Approach for Quality of Service Management

DTIC Science & Technology

1998-10-01

architecture enables us to quantitatively measure QoS, and to analytically plan and allocate resource. This work was supported in part by the Defense...in their requirements for the rate of services and resources available to them at the time of use of the application systems. Therefore there is an...system should be able to reconcile these different demands to maximize the user’s preference and to make the most effective use of the system. So it

Designing area optimized application-specific network-on-chip architectures while providing hard QoS guarantees.

PubMed

Khawaja, Sajid Gul; Mushtaq, Mian Hamza; Khan, Shoab A; Akram, M Usman; Jamal, Habib Ullah

2015-01-01

With the increase of transistors' density, popularity of System on Chip (SoC) has increased exponentially. As a communication module for SoC, Network on Chip (NoC) framework has been adapted as its backbone. In this paper, we propose a methodology for designing area-optimized application specific NoC while providing hard Quality of Service (QoS) guarantees for real time flows. The novelty of the proposed system lies in derivation of a Mixed Integer Linear Programming model which is then used to generate a resource optimal Network on Chip (NoC) topology and architecture while considering traffic and QoS requirements. We also present the micro-architectural design features used for enabling traffic and latency guarantees and discuss how the solution adapts for dynamic variations in the application traffic. The paper highlights the effectiveness of proposed method by generating resource efficient NoC solutions for both industrial and benchmark applications. The area-optimized results are generated in few seconds by proposed technique, without resorting to heuristics, even for an application with 48 traffic flows.

Designing Area Optimized Application-Specific Network-On-Chip Architectures while Providing Hard QoS Guarantees

PubMed Central

Khawaja, Sajid Gul; Mushtaq, Mian Hamza; Khan, Shoab A.; Akram, M. Usman; Jamal, Habib ullah

2015-01-01

With the increase of transistors' density, popularity of System on Chip (SoC) has increased exponentially. As a communication module for SoC, Network on Chip (NoC) framework has been adapted as its backbone. In this paper, we propose a methodology for designing area-optimized application specific NoC while providing hard Quality of Service (QoS) guarantees for real time flows. The novelty of the proposed system lies in derivation of a Mixed Integer Linear Programming model which is then used to generate a resource optimal Network on Chip (NoC) topology and architecture while considering traffic and QoS requirements. We also present the micro-architectural design features used for enabling traffic and latency guarantees and discuss how the solution adapts for dynamic variations in the application traffic. The paper highlights the effectiveness of proposed method by generating resource efficient NoC solutions for both industrial and benchmark applications. The area-optimized results are generated in few seconds by proposed technique, without resorting to heuristics, even for an application with 48 traffic flows. PMID:25898016

Quality of service policy control in virtual private networks

NASA Astrophysics Data System (ADS)

Yu, Yiqing; Wang, Hongbin; Zhou, Zhi; Zhou, Dongru

2004-04-01

This paper studies the QoS of VPN in an environment where the public network prices connection-oriented services based on source, destination and grade of service, and advertises these prices to its VPN customers (users). As different QoS technologies can produce different QoS, there are according different traffic classification rules and priority rules. The internet service provider (ISP) may need to build complex mechanisms separately for each node. In order to reduce the burden of network configuration, we need to design policy control technologies. We considers mainly directory server, policy server, policy manager and policy enforcers. Policy decision point (PDP) decide its control according to policy rules. In network, policy enforce point (PEP) decide its network controlled unit. For InterServ and DiffServ, we will adopt different policy control methods as following: (1) In InterServ, traffic uses resource reservation protocol (RSVP) to guarantee the network resource. (2) In DiffServ, policy server controls the DiffServ code points and per hop behavior (PHB), its PDP distributes information to each network node. Policy server will function as following: information searching; decision mechanism; decision delivering; auto-configuration. In order to prove the effectiveness of QoS policy control, we make the corrective simulation.

Intelligent call admission control for multi-class services in mobile cellular networks

NASA Astrophysics Data System (ADS)

Ma, Yufeng; Hu, Xiulin; Zhang, Yunyu

2005-11-01

Scarcity of the spectrum resource and mobility of users make quality of service (QoS) provision a critical issue in mobile cellular networks. This paper presents a fuzzy call admission control scheme to meet the requirement of the QoS. A performance measure is formed as a weighted linear function of new call and handoff call blocking probabilities of each service class. Simulation compares the proposed fuzzy scheme with complete sharing and guard channel policies. Simulation results show that fuzzy scheme has a better robust performance in terms of average blocking criterion.

FSO and quality of service software prediction

NASA Astrophysics Data System (ADS)

Bouchet, O.; Marquis, T.; Chabane, M.; Alnaboulsi, M.; Sizun, H.

2005-08-01

Free-space optical (FSO) communication links constitute an alternative option to radio relay links and to optical cables facing growth needs in high-speed telecommunications (abundance of unregulated bandwidth, rapid installation, availability of low-cost optical components offering a high data rate, etc). Their operationalisation requires a good knowledge of the atmospheric effects which can negatively affect role propagation and the availability of the link, and thus to the quality of service (QoS). Better control of these phenomena will allow for the evaluation of system performance and thus assist with improving reliability. The aim of this paper is to compare the behavior of a FSO link located in south of France (Toulouse: with the following parameters: around 270 meters (0.2 mile) long, 34 Mbps data rate, 850 nm wavelength and PDH frame) with airport meteorological data. The second aim of the paper is to assess in-house FSO quality of service prediction software, through comparing simulations with the optical link data and the weather data. The analysis uses in-house software FSO quality of service prediction software ("FSO Prediction") developed by France Telecom Research & Development, which integrates news fog fading equations (compare to Kim & al.) and includes multiple effects (geometrical attenuation, atmospheric fading, rain, snow, scintillation and refraction attenuation due to atmospheric turbulence, optical mispointing attenuation). The FSO link field trial, intended to enable the demonstration and evaluation of these different effects, is described; and preliminary results of the field trial, from December 2004 to May 2005, are then presented.

Capacity allocation mechanism based on differentiated QoS in 60 GHz radio-over-fiber local access network

NASA Astrophysics Data System (ADS)

Kou, Yanbin; Liu, Siming; Zhang, Weiheng; Shen, Guansheng; Tian, Huiping

2017-03-01

We present a dynamic capacity allocation mechanism based on the Quality of Service (QoS) for different mobile users (MU) in 60 GHz radio-over-fiber (RoF) local access networks. The proposed mechanism is capable for collecting the request information of MUs to build a full list of MU capacity demands and service types at the Central Office (CO). A hybrid algorithm is introduced to implement the capacity allocation which can satisfy the requirements of different MUs at different network traffic loads. Compared with the weight dynamic frames assignment (WDFA) scheme, the Hybrid scheme can keep high priority MUs in low delay and maintain the packet loss rate less than 1% simultaneously. At the same time, low priority MUs have a relatively better performance.

Enabling Broadband as Commodity within Access Networks: A QoS Recipe

NASA Astrophysics Data System (ADS)

Areizaga, Enrique; Foglar, Andreas; Elizondo, Antonio J.; Geilhardt, Frank

This paper describes the QoS features that will transform the access networks landscape in order to bring “Broadband” as a commodity while setting up the pillars of the “Future Media Internet”. Quality of Experience is obviously key for emerging and future services. Broadcasting services will first need to equal the QoE of their counterparts in the Open-air market (for IP-TV examples would be artifact-free, no picture freezing, fast zapping times) and offer new features often using interactivity (Time-shifted TV, access to more content, 3DTV with feeling of presence). The huge variety of communications alternatives will lead to different requirements per customer, whose needs will also be dependent on parameters like where the connection is made, the time of the day/day of the week/period of the year or even his/her mood. Today’s networks, designed for providing just Broadband connectivity, will not be enough to satisfy customer’s needs and will necessarily support the introduction of new and innovative services. The Networks of the future should learn from the way the users are communicating, what services they are using, where, when, and how, and adapt accordingly.

A Framework for Analyzing and Testing the Performance of Software Services

NASA Astrophysics Data System (ADS)

Bertolino, Antonia; de Angelis, Guglielmo; di Marco, Antinisca; Inverardi, Paola; Sabetta, Antonino; Tivoli, Massimo

Networks "Beyond the 3rd Generation" (B3G) are characterized by mobile and resource-limited devices that communicate through different kinds of network interfaces. Software services deployed in such networks shall adapt themselves according to possible execution contexts and requirement changes. At the same time, software services have to be competitive in terms of the Quality of Service (QoS) provided, or perceived by the end user.

A Study of Quality of Service Communication for High-Speed Packet-Switching Computer Sub-Networks

NASA Technical Reports Server (NTRS)

Cui, Zhenqian

1999-01-01

With the development of high-speed networking technology, computer networks, including local-area networks (LANs), wide-area networks (WANs) and the Internet, are extending their traditional roles of carrying computer data. They are being used for Internet telephony, multimedia applications such as conferencing and video on demand, distributed simulations, and other real-time applications. LANs are even used for distributed real-time process control and computing as a cost-effective approach. Differing from traditional data transfer, these new classes of high-speed network applications (video, audio, real-time process control, and others) are delay sensitive. The usefulness of data depends not only on the correctness of received data, but also the time that data are received. In other words, these new classes of applications require networks to provide guaranteed services or quality of service (QoS). Quality of service can be defined by a set of parameters and reflects a user's expectation about the underlying network's behavior. Traditionally, distinct services are provided by different kinds of networks. Voice services are provided by telephone networks, video services are provided by cable networks, and data transfer services are provided by computer networks. A single network providing different services is called an integrated-services network.

Seamless interworking architecture for WBAN in heterogeneous wireless networks with QoS guarantees.

PubMed

Khan, Pervez; Ullah, Niamat; Ullah, Sana; Kwak, Kyung Sup

2011-10-01

The IEEE 802.15.6 standard is a communication standard optimized for low-power and short-range in-body/on-body nodes to serve a variety of medical, consumer electronics and entertainment applications. Providing high mobility with guaranteed Quality of Service (QoS) to a WBAN user in heterogeneous wireless networks is a challenging task. A WBAN uses a Personal Digital Assistant (PDA) to gather data from body sensors and forwards it to a remote server through wide range wireless networks. In this paper, we present a coexistence study of WBAN with Wireless Local Area Networks (WLAN) and Wireless Wide Area Networks (WWANs). The main issue is interworking of WBAN in heterogenous wireless networks including seamless handover, QoS, emergency services, cooperation and security. We propose a Seamless Interworking Architecture (SIA) for WBAN in heterogenous wireless networks based on a cost function. The cost function is based on power consumption and data throughput costs. Our simulation results show that the proposed scheme outperforms typical approaches in terms of throughput, delay and packet loss rate.

Ephedrine QoS: An Antidote to Slow, Congested, Bufferless NoCs

PubMed Central

Fang, Juan; Yao, Zhicheng; Sui, Xiufeng; Bao, Yungang

2014-01-01

Datacenters consolidate diverse applications to improve utilization. However when multiple applications are colocated on such platforms, contention for shared resources like networks-on-chip (NoCs) can degrade the performance of latency-critical online services (high-priority applications). Recently proposed bufferless NoCs (Nychis et al.) have the advantages of requiring less area and power, but they pose challenges in quality-of-service (QoS) support, which usually relies on buffer-based virtual channels (VCs). We propose QBLESS, a QoS-aware bufferless NoC scheme for datacenters. QBLESS consists of two components: a routing mechanism (QBLESS-R) that can substantially reduce flit deflection for high-priority applications and a congestion-control mechanism (QBLESS-CC) that guarantees performance for high-priority applications and improves overall system throughput. We use trace-driven simulation to model a 64-core system, finding that, when compared to BLESS, a previous state-of-the-art bufferless NoC design, QBLESS, improves performance of high-priority applications by an average of 33.2% and reduces network-hops by an average of 42.8%. PMID:25250386

QoS prediction for web services based on user-trust propagation model

NASA Astrophysics Data System (ADS)

Thinh, Le-Van; Tu, Truong-Dinh

2017-10-01

There is an important online role for Web service providers and users; however, the rapidly growing number of service providers and users, it can create some similar functions among web services. This is an exciting area for research, and researchers seek to to propose solutions for the best service to users. Collaborative filtering (CF) algorithms are widely used in recommendation systems, although these are less effective for cold-start users. Recently, some recommender systems have been developed based on social network models, and the results show that social network models have better performance in terms of CF, especially for cold-start users. However, most social network-based recommendations do not consider the user's mood. This is a hidden source of information, and is very useful in improving prediction efficiency. In this paper, we introduce a new model called User-Trust Propagation (UTP). The model uses a combination of trust and the mood of users to predict the QoS value and matrix factorisation (MF), which is used to train the model. The experimental results show that the proposed model gives better accuracy than other models, especially for the cold-start problem.

Quality of Service for Real-Time Applications Over Next Generation Data Networks

NASA Technical Reports Server (NTRS)

Ivancic, William; Atiquzzaman, Mohammed; Bai, Haowei; Su, Hongjun; Jain, Raj; Duresi, Arjan; Goyal, Mukyl; Bharani, Venkata; Liu, Chunlei; Kota, Sastri

2001-01-01

This project, which started on January 1, 2000, was funded by NASA Glenn Research Center for duration of one year. The deliverables of the project included the following tasks: Study of QoS mapping between the edge and core networks envisioned in the Next Generation networks will provide us with the QoS guarantees that can be obtained from next generation networks. Buffer management techniques to provide strict guarantees to real-time end-to-end applications through preferential treatment to packets belonging to real-time applications. In particular, use of ECN to help reduce the loss on high bandwidth-delay product satellite networks needs to be studied. Effect of Prioritized Packet Discard to increase goodput of the network and reduce the buffering requirements in the ATM switches. Provision of new IP circuit emulation services over Satellite IP backbones using MPLS will be studied. Determine the architecture and requirements for internetworking ATN and the Next Generation Internet for real-time applications.

Using heuristic algorithms for capacity leasing and task allocation issues in telecommunication networks under fuzzy quality of service constraints

NASA Astrophysics Data System (ADS)

Huseyin Turan, Hasan; Kasap, Nihat; Savran, Huseyin

2014-03-01

Nowadays, every firm uses telecommunication networks in different amounts and ways in order to complete their daily operations. In this article, we investigate an optimisation problem that a firm faces when acquiring network capacity from a market in which there exist several network providers offering different pricing and quality of service (QoS) schemes. The QoS level guaranteed by network providers and the minimum quality level of service, which is needed for accomplishing the operations are denoted as fuzzy numbers in order to handle the non-deterministic nature of the telecommunication network environment. Interestingly, the mathematical formulation of the aforementioned problem leads to the special case of a well-known two-dimensional bin packing problem, which is famous for its computational complexity. We propose two different heuristic solution procedures that have the capability of solving the resulting nonlinear mixed integer programming model with fuzzy constraints. In conclusion, the efficiency of each algorithm is tested in several test instances to demonstrate the applicability of the methodology.

Efficient QoS-aware Service Composition

NASA Astrophysics Data System (ADS)

Alrifai, Mohammad; Risse, Thomas

Web service composition requests are usually combined with endto-end QoS requirements, which are specified in terms of non-functional properties (e.g. response time, throughput and price). The goal of QoS-aware service composition is to find the best combination of services such that their aggregated QoS values meet these end-to-end requirements. Local selection techniques are very efficient but fail short in handling global QoS constraints. Global optimization techniques, on the other hand, can handle global constraints, but their poor performance render them inappropriate for applications with dynamic and real-time requirements. In this paper we address this problem and propose a solution that combines global optimization with local selection techniques for achieving a better performance. The proposed solution consists of two steps: first we use mixed integer linear programming (MILP) to find the optimal decomposition of global QoS constraints into local constraints. Second, we use local search to find the best web services that satisfy these local constraints. Unlike existing MILP-based global planning solutions, the size of the MILP model in our case is much smaller and independent on the number of available services, yields faster computation and more scalability. Preliminary experiments have been conducted to evaluate the performance of the proposed solution.

Reliable Execution Based on CPN and Skyline Optimization for Web Service Composition

PubMed Central

Ha, Weitao; Zhang, Guojun

2013-01-01

With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets. PMID:23935431

Reliable execution based on CPN and skyline optimization for Web service composition.

PubMed

Chen, Liping; Ha, Weitao; Zhang, Guojun

2013-01-01

With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets.

Modeling and performance analysis of QoS data

NASA Astrophysics Data System (ADS)

Strzeciwilk, Dariusz; Zuberek, Włodzimierz M.

2016-09-01

The article presents the results of modeling and analysis of data transmission performance on systems that support quality of service. Models are designed and tested, taking into account multiservice network architecture, i.e. supporting the transmission of data related to different classes of traffic. Studied were mechanisms of traffic shaping systems, which are based on the Priority Queuing with an integrated source of data and the various sources of data that is generated. Discussed were the basic problems of the architecture supporting QoS and queuing systems. Designed and built were models based on Petri nets, supported by temporal logics. The use of simulation tools was to verify the mechanisms of shaping traffic with the applied queuing algorithms. It is shown that temporal models of Petri nets can be effectively used in the modeling and analysis of the performance of computer networks.

Negotiation and Monitoring of Service Level Agreements

NASA Astrophysics Data System (ADS)

Quillinan, Thomas B.; Clark, Kassidy P.; Warnier, Martijn; Brazier, Frances M. T.; Rana, Omer

Service level agreements (SLAs) provide a means to define specific Quality of Service (QoS) guarantees between providers and consumers of services. Negotiation and definition of these QoS characteristics is an area of significant research. However, defining the actions that take place when an agreement is violated is a topic of more recent focus. This paper discusses recent advances in this field and propose some additional features that can help both consumers and producers during the enactment of services. These features include the ability to (re)negotiate penalties in an agreement, and specifically focuses on the renegotiation of penalties during enactment to reflect ongoing violations.

Integrating QoS and security functions in an IP-VPN gateway

NASA Astrophysics Data System (ADS)

Fan, Kuo-Pao; Chang, Shu-Hsin; Lin, Kuan-Ming; Pen, Mau-Jy

2001-10-01

IP-based Virtual Private Network becomes more and more popular. It can not only reduce the enterprise communication cost but also increase the revenue of the service provider. The common IP-VPN application types include Intranet VPN, Extranet VPN, and remote access VPN. For the large IP-VPN market, some vendors develop dedicated IP-VPN devices; while some vendors add the VPN functions into their existing network equipment such as router, access gateway, etc. The functions in the IP-VPN device include security, QoS, and management. The common security functions supported are IPSec (IP Security), IKE (Internet Key Exchange), and Firewall. The QoS functions include bandwidth control and packet scheduling. In the management component, policy-based network management is under standardization in IETF. In this paper, we discuss issues on how to integrate the QoS and security functions in an IP-VPN Gateway. We propose three approaches to do this. They are (1) perform Qos first (2) perform IPSec first and (3) reserve fixed bandwidth for IPSec. We also compare the advantages and disadvantages of the three proposed approaches.

A fuzzy multi-objective model for capacity allocation and pricing policy of provider in data communication service with different QoS levels

NASA Astrophysics Data System (ADS)

Pan, Wei; Wang, Xianjia; Zhong, Yong-guang; Yu, Lean; Jie, Cao; Ran, Lun; Qiao, Han; Wang, Shouyang; Xu, Xianhao

2012-06-01

Data communication service has an important influence on e-commerce. The key challenge for the users is, ultimately, to select a suitable provider. However, in this article, we do not focus on this aspect but the viewpoint and decision-making of providers for order allocation and pricing policy when orders exceed service capacity. It is a multiple criteria decision-making problem such as profit and cancellation ratio. Meanwhile, we know realistic situations in which much of the input information is uncertain. Thus, it becomes very complex in a real-life environment. In this situation, fuzzy sets theory is the best tool for solving this problem. Our fuzzy model is formulated in such a way as to simultaneously consider the imprecision of information, price sensitive demand, stochastic variables, cancellation fee and the general membership function. For solving the problem, a new fuzzy programming is developed. Finally, a numerical example is presented to illustrate the proposed method. The results show that it is effective for determining the suitable order set and pricing policy of provider in data communication service with different quality of service (QoS) levels.

Exploring Issues of Quality of Service in a Next Generation Internet Testbed: A Case Study Using PathMaster

PubMed Central

Shifman, Mark A.; Sayward, Frederick G.; Mattie, Mark E.; Miller, Perry L.

2002-01-01

This case study describes a project that explores issues of quality of service (QoS) relevant to the next-generation Internet (NGI), using the PathMaster application in a testbed environment. PathMaster is a prototype computer system that analyzes digitized cell images from cytology specimens and compares those images against an image database, returning a ranked set of “similar” cell images from the database. To perform NGI testbed evaluations, we used a cluster of nine parallel computation workstations configured as three subclusters using Cisco routers. This architecture provides a local “simulated Internet” in which we explored the following QoS strategies: (1) first-in-first-out queuing, (2) priority queuing, (3) weighted fair queuing, (4) weighted random early detection, and (5) traffic shaping. The study describes the results of using these strategies with a distributed version of the PathMaster system in the presence of different amounts of competing network traffic and discusses certain of the issues that arise. The goal of the study is to help introduce NGI QoS issues to the Medical Informatics community and to use the PathMaster NGI testbed to illustrate concretely certain of the QoS issues that arise. PMID:12223501

The extended TRIP supporting VoIP routing reservation with distributed QoS

NASA Astrophysics Data System (ADS)

Wang, Furong; Wu, Ye

2004-04-01

In this paper, an existing protocol, i.e. TRIP (Telephony Routing over IP) is developed to provide distributed QoS when making resource reservations for VoIP services such as H.323, SIP. Enhanced LSs (location servers) are deployed in ITADs (IP Telephony Administrative Domains) to take in charge of intra-domain routing policy because of small propagation price. It is an easy way to find an IP telephone route for intra-domain VoIP media association and simultaneously possess intra-domain load balancing features. For those routing reservations bridging domains, inter-domain routing policy is responsible for finding the shortest inter-domain route with enough resources. I propose the routing preference policy based on QoS price when the session traffic is shaped by a token bucket, related QoS messages, and message cooperation.

Congestion Prediction Modeling for Quality of Service Improvement in Wireless Sensor Networks

PubMed Central

Lee, Ga-Won; Lee, Sung-Young; Huh, Eui-Nam

2014-01-01

Information technology (IT) is pushing ahead with drastic reforms of modern life for improvement of human welfare. Objects constitute “Information Networks” through smart, self-regulated information gathering that also recognizes and controls current information states in Wireless Sensor Networks (WSNs). Information observed from sensor networks in real-time is used to increase quality of life (QoL) in various industries and daily life. One of the key challenges of the WSNs is how to achieve lossless data transmission. Although nowadays sensor nodes have enhanced capacities, it is hard to assure lossless and reliable end-to-end data transmission in WSNs due to the unstable wireless links and low hard ware resources to satisfy high quality of service (QoS) requirements. We propose a node and path traffic prediction model to predict and minimize the congestion. This solution includes prediction of packet generation due to network congestion from both periodic and event data generation. Simulation using NS-2 and Matlab is used to demonstrate the effectiveness of the proposed solution. PMID:24784035

An Automatic Web Service Composition Framework Using QoS-Based Web Service Ranking Algorithm.

PubMed

Mallayya, Deivamani; Ramachandran, Baskaran; Viswanathan, Suganya

2015-01-01

Web service has become the technology of choice for service oriented computing to meet the interoperability demands in web applications. In the Internet era, the exponential addition of web services nominates the "quality of service" as essential parameter in discriminating the web services. In this paper, a user preference based web service ranking (UPWSR) algorithm is proposed to rank web services based on user preferences and QoS aspect of the web service. When the user's request cannot be fulfilled by a single atomic service, several existing services should be composed and delivered as a composition. The proposed framework allows the user to specify the local and global constraints for composite web services which improves flexibility. UPWSR algorithm identifies best fit services for each task in the user request and, by choosing the number of candidate services for each task, reduces the time to generate the composition plans. To tackle the problem of web service composition, QoS aware automatic web service composition (QAWSC) algorithm proposed in this paper is based on the QoS aspects of the web services and user preferences. The proposed framework allows user to provide feedback about the composite service which improves the reputation of the services.

An Automatic Web Service Composition Framework Using QoS-Based Web Service Ranking Algorithm

PubMed Central

Mallayya, Deivamani; Ramachandran, Baskaran; Viswanathan, Suganya

2015-01-01

Web service has become the technology of choice for service oriented computing to meet the interoperability demands in web applications. In the Internet era, the exponential addition of web services nominates the “quality of service” as essential parameter in discriminating the web services. In this paper, a user preference based web service ranking (UPWSR) algorithm is proposed to rank web services based on user preferences and QoS aspect of the web service. When the user's request cannot be fulfilled by a single atomic service, several existing services should be composed and delivered as a composition. The proposed framework allows the user to specify the local and global constraints for composite web services which improves flexibility. UPWSR algorithm identifies best fit services for each task in the user request and, by choosing the number of candidate services for each task, reduces the time to generate the composition plans. To tackle the problem of web service composition, QoS aware automatic web service composition (QAWSC) algorithm proposed in this paper is based on the QoS aspects of the web services and user preferences. The proposed framework allows user to provide feedback about the composite service which improves the reputation of the services. PMID:26504894

Semantic Network Adaptation Based on QoS Pattern Recognition for Multimedia Streams

NASA Astrophysics Data System (ADS)

Exposito, Ernesto; Gineste, Mathieu; Lamolle, Myriam; Gomez, Jorge

This article proposes an ontology based pattern recognition methodology to compute and represent common QoS properties of the Application Data Units (ADU) of multimedia streams. The use of this ontology by mechanisms located at different layers of the communication architecture will allow implementing fine per-packet self-optimization of communication services regarding the actual application requirements. A case study showing how this methodology is used by error control mechanisms in the context of wireless networks is presented in order to demonstrate the feasibility and advantages of this approach.

Service differentiated and adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems.

PubMed

Xia, Feng; Li, Jie; Hao, Ruonan; Kong, Xiangjie; Gao, Ruixia

2013-01-01

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

Service Differentiated and Adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems

PubMed Central

Gao, Ruixia

2013-01-01

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay. PMID:24260021

Interference Drop Scheme: Enhancing QoS Provision in Multi-Hop Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Luo, Chang-Yi; Komuro, Nobuyoshi; Takahashi, Kiyoshi; Kasai, Hiroyuki; Ueda, Hiromi; Tsuboi, Toshinori

Ad hoc networking uses wireless technologies to construct networks with no physical infrastructure and so are expected to provide instant networking in areas such as disaster recovery sites and inter-vehicle communication. Unlike conventional wired networks services, services in ad hoc networks are easily disrupted by the frequent changes in traffic and topology. Therefore, solutions to assure the Quality of Services (QoS) in ad hoc networks are different from the conventional ones used in wired networks. In this paper, we propose a new queue management scheme, Interference Drop Scheme (IDS) for ad hoc networks. In the conventional queue management approaches such as FIFO (First-in First-out) and RED (Random Early Detection), a queue is usually managed by a queue length limit. FIFO discards packets according to the queue limit, and RED discards packets in an early and random fashion. IDS, on the other hand, manages the queue according to wireless interference time, which increases as the number of contentions in the MAC layer increases. When there are many MAC contentions, IDS discards TCP data packets. By observing the interference time and discarding TCP data packets, our simulation results show that IDS improves TCP performance and reduces QoS violations in UDP in ad hoc networks with chain, grid, and random topologies. Our simulation results also demonstrate that wireless interference time is a better metric than queue length limit for queue management in multi-hop ad hoc networks.

On service differentiation in mobile Ad Hoc networks.

PubMed

Zhang, Shun-liang; Ye, Cheng-qing

2004-09-01

A network model is proposed to support service differentiation for mobile Ad Hoc networks by combining a fully distributed admission control approach and the DIFS based differentiation mechanism of IEEE802.11. It can provide different kinds of QoS (Quality of Service) for various applications. Admission controllers determine a committed bandwidth based on the reserved bandwidth of flows and the source utilization of networks. Packets are marked when entering into networks by markers according to the committed rate. By the mark in the packet header, intermediate nodes handle the received packets in different manners to provide applications with the QoS corresponding to the pre-negotiated profile. Extensive simulation experiments showed that the proposed mechanism can provide QoS guarantee to assured service traffic and increase the channel utilization of networks.

A novel PON based UMTS broadband wireless access network architecture with an algorithm to guarantee end to end QoS

NASA Astrophysics Data System (ADS)

Sana, Ajaz; Hussain, Shahab; Ali, Mohammed A.; Ahmed, Samir

2007-09-01

In this paper we proposes a novel Passive Optical Network (PON) based broadband wireless access network architecture to provide multimedia services (video telephony, video streaming, mobile TV, mobile emails etc) to mobile users. In the conventional wireless access networks, the base stations (Node B) and Radio Network Controllers (RNC) are connected by point to point T1/E1 lines (Iub interface). The T1/E1 lines are expensive and add up to operating costs. Also the resources (transceivers and T1/E1) are designed for peak hours traffic, so most of the time the dedicated resources are idle and wasted. Further more the T1/E1 lines are not capable of supporting bandwidth (BW) required by next generation wireless multimedia services proposed by High Speed Packet Access (HSPA, Rel.5) for Universal Mobile Telecommunications System (UMTS) and Evolution Data only (EV-DO) for Code Division Multiple Access 2000 (CDMA2000). The proposed PON based back haul can provide Giga bit data rates and Iub interface can be dynamically shared by Node Bs. The BW is dynamically allocated and the unused BW from lightly loaded Node Bs is assigned to heavily loaded Node Bs. We also propose a novel algorithm to provide end to end Quality of Service (QoS) (between RNC and user equipment).The algorithm provides QoS bounds in the wired domain as well as in wireless domain with compensation for wireless link errors. Because of the air interface there can be certain times when the user equipment (UE) is unable to communicate with Node B (usually referred to as link error). Since the link errors are bursty and location dependent. For a proposed approach, the scheduler at the Node B maps priorities and weights for QoS into wireless MAC. The compensations for errored links is provided by the swapping of services between the active users and the user data is divided into flows, with flows allowed to lag or lead. The algorithm guarantees (1)delay and throughput for error-free flows,(2)short term fairness

Automated geospatial Web Services composition based on geodata quality requirements

NASA Astrophysics Data System (ADS)

Cruz, Sérgio A. B.; Monteiro, Antonio M. V.; Santos, Rafael

2012-10-01

Service-Oriented Architecture and Web Services technologies improve the performance of activities involved in geospatial analysis with a distributed computing architecture. However, the design of the geospatial analysis process on this platform, by combining component Web Services, presents some open issues. The automated construction of these compositions represents an important research topic. Some approaches to solving this problem are based on AI planning methods coupled with semantic service descriptions. This work presents a new approach using AI planning methods to improve the robustness of the produced geospatial Web Services composition. For this purpose, we use semantic descriptions of geospatial data quality requirements in a rule-based form. These rules allow the semantic annotation of geospatial data and, coupled with the conditional planning method, this approach represents more precisely the situations of nonconformities with geodata quality that may occur during the execution of the Web Service composition. The service compositions produced by this method are more robust, thus improving process reliability when working with a composition of chained geospatial Web Services.

Economic model for QoS guarantee on the Internet

NASA Astrophysics Data System (ADS)

Zhang, Chi; Wei, Jiaolong

2001-09-01

This paper describes a QoS guarantee architecture suited for best-effort environments, based on ideas from microeconomics and non-cooperative game theory. First, an analytic model is developed for the study of the resource allocation in the Internet. Then we show that with a simple pricing mechanism (from network implementation and users' points-of-view), we were able to provide QoS guarantee at per flow level without resource allocation or complicated scheduling mechanisms or maintaining per flow state in the core network. Unlike the previous work on this area, we extend the basic model to support inelastic applications which require minimum bandwidth guarantees for a given time period by introducing derivative market.

You Can Make Your Facilities Services Provider Part of the College Community.

ERIC Educational Resources Information Center

Ledbetter, Randy

2002-01-01

Discusses five attributes that, when well implemented, form the framework for successful relationships between college administration and services companies: reporting relationships, Quality of Service (QoS) measures, formal reports and reviews, employee relations, and subcontractor relations. (EV)

Double Threshold Energy Detection Based Cooperative Spectrum Sensing for Cognitive Radio Networks with QoS Guarantee

NASA Astrophysics Data System (ADS)

Hu, Hang; Yu, Hong; Zhang, Yongzhi

2013-03-01

Cooperative spectrum sensing, which can greatly improve the ability of discovering the spectrum opportunities, is regarded as an enabling mechanism for cognitive radio (CR) networks. In this paper, we employ a double threshold detection method in energy detector to perform spectrum sensing, only the CR users with reliable sensing information are allowed to transmit one bit local decision to the fusion center. Simulation results will show that our proposed double threshold detection method could not only improve the sensing performance but also save the bandwidth of the reporting channel compared with the conventional detection method with one threshold. By weighting the sensing performance and the consumption of system resources in a utility function that is maximized with respect to the number of CR users, it has been shown that the optimal number of CR users is related to the price of these Quality-of-Service (QoS) requirements.

Mixed integer nonlinear programming model of wireless pricing scheme with QoS attribute of bandwidth and end-to-end delay

NASA Astrophysics Data System (ADS)

Irmeilyana, Puspita, Fitri Maya; Indrawati

2016-02-01

The pricing for wireless networks is developed by considering linearity factors, elasticity price and price factors. Mixed Integer Nonlinear Programming of wireless pricing model is proposed as the nonlinear programming problem that can be solved optimally using LINGO 13.0. The solutions are expected to give some information about the connections between the acceptance factor and the price. Previous model worked on the model that focuses on bandwidth as the QoS attribute. The models attempt to maximize the total price for a connection based on QoS parameter. The QoS attributes used will be the bandwidth and the end to end delay that affect the traffic. The maximum goal to maximum price is achieved when the provider determine the requirement for the increment or decrement of price change due to QoS change and amount of QoS value.

Asynchronous Object Storage with QoS for Scientific and Commercial Big Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brim, Michael J; Dillow, David A; Oral, H Sarp

2013-01-01

This paper presents our design for an asynchronous object storage system intended for use in scientific and commercial big data workloads. Use cases from the target workload do- mains are used to motivate the key abstractions used in the application programming interface (API). The architecture of the Scalable Object Store (SOS), a prototype object stor- age system that supports the API s facilities, is presented. The SOS serves as a vehicle for future research into scalable and resilient big data object storage. We briefly review our research into providing efficient storage servers capable of providing quality of service (QoS) contractsmore » relevant for big data use cases.« less

Reinforcement Learning Based Web Service Compositions for Mobile Business

NASA Astrophysics Data System (ADS)

Zhou, Juan; Chen, Shouming

In this paper, we propose a new solution to Reactive Web Service Composition, via molding with Reinforcement Learning, and introducing modified (alterable) QoS variables into the model as elements in the Markov Decision Process tuple. Moreover, we give an example of Reactive-WSC-based mobile banking, to demonstrate the intrinsic capability of the solution in question of obtaining the optimized service composition, characterized by (alterable) target QoS variable sets with optimized values. Consequently, we come to the conclusion that the solution has decent potentials in boosting customer experiences and qualities of services in Web Services, and those in applications in the whole electronic commerce and business sector.

Quality of Service for Real-Time Applications Over Next Generation Data Networks

NASA Technical Reports Server (NTRS)

Atiquzzaman, Mohammed; Jain, Raj

2001-01-01

This project, which started on January 1, 2000, was funded by the NASA Glenn Research Center for duration of one year. The deliverables of the project included the following tasks: (1) Study of QoS mapping between the edge and core networks envisioned in the Next Generation networks will provide us with the QoS guarantees that can be obtained from next generation networks; (2) Buffer management techniques to provide strict guarantees to real-time end-to-end applications through preferential treatment to packets belonging to real-time applications. In particular, use of ECN to help reduce the loss on high bandwidth-delay product satellite networks needs to be studied; (3) Effect of Prioritized Packet Discard to increase goodput of the network and reduce the buffering requirements in the ATM switches; (4) Provision of new IP circuit emulation services over Satellite IP backbones using MPLS will be studied; and (5) Determine the architecture and requirements for internetworking ATN and the Next Generation Internet for real-time applications. The project has been completed on time. All the objectives and deliverables of the project have been completed. Research results obtained from this project have been published in a number of papers in journals, conferences, and technical reports, included in this document.

Device Centric Throughput and QoS Optimization for IoTsin a Smart Building Using CRN-Techniques

PubMed Central

Aslam, Saleem; Hasan, Najam Ul; Shahid, Adnan; Jang, Ju Wook; Lee, Kyung-Geun

2016-01-01

The Internet of Things (IoT) has gained an incredible importance in the communication and networking industry due to its innovative solutions and advantages in diverse domains. The IoT’ network is a network of smart physical objects: devices, vehicles, buildings, etc. The IoT has a number of applications ranging from smart home, smart surveillance to smart healthcare systems. Since IoT consists of various heterogeneous devices that exhibit different traffic patterns and expect different quality of service (QoS) in terms of data rate, bit error rate and the stability index of the channel, therefore, in this paper, we formulated an optimization problem to assign channels to heterogeneous IoT devices within a smart building for the provisioning of their desired QoS. To solve this problem, a novel particle swarm optimization-based algorithm is proposed. Then, exhaustive simulations are carried out to evaluate the performance of the proposed algorithm. Simulation results demonstrate the supremacy of our proposed algorithm over the existing ones in terms of throughput, bit error rate and the stability index of the channel. PMID:27782057

A novel client service quality measuring model and an eHealthcare mitigating approach.

PubMed

Cheng, L M; Choi, Wai Ping Choi; Wong, Anita Yiu Ming

2016-07-01

Facing population ageing in Hong Kong, the demand of long-term elderly health care services is increasing. The challenge is to support a good quality service under the constraints faced by recent shortage of nursing and care services professionals without redesigning the work flow operated in the existing elderly health care industries. the existing elderly health care industries. The Total QoS measure based on Finite Capacity Queuing Model is a reliable method and an effective measurement for Quality of services. The value is good for measuring the staffing level and offers a measurement for efficiency enhancement when incorporate new technologies like ICT. The implemented system has improved the Quality of Service by more than 14% and the extra released manpower resource will allow clinical care provider to offer further value added services without actually increasing head count. We have developed a novel Quality of Service measurement for Clinical Care services based on multi-queue using finite capacity queue model M/M/c/K/n and the measurement is useful for estimating the shortage of staff resource in a caring institution. It is essential for future integration with the existing widely used assessment model to develop reliable measuring limits which allow an effective measurement of public fund used in health care industries. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

S-Cube: Enabling the Next Generation of Software Services

NASA Astrophysics Data System (ADS)

Metzger, Andreas; Pohl, Klaus

The Service Oriented Architecture (SOA) paradigm is increasingly adopted by industry for building distributed software systems. However, when designing, developing and operating innovative software services and servicebased systems, several challenges exist. Those challenges include how to manage the complexity of those systems, how to establish, monitor and enforce Quality of Service (QoS) and Service Level Agreements (SLAs), as well as how to build those systems such that they can proactively adapt to dynamically changing requirements and context conditions. Developing foundational solutions for those challenges requires joint efforts of different research communities such as Business Process Management, Grid Computing, Service Oriented Computing and Software Engineering. This paper provides an overview of S-Cube, the European Network of Excellence on Software Services and Systems. S-Cube brings together researchers from leading research institutions across Europe, who join their competences to develop foundations, theories as well as methods and tools for future service-based systems.

Research on the business QoS and trustworthy and controllable strategies mechanism for energy internet

NASA Astrophysics Data System (ADS)

Zhang, Geng; Lu, Meiling; Zhang, Dahua; Zhou, Liang; Li, Likang

2017-01-01

Energy internet is a kind of power sharing network, which can realize the bidirectional flow of energy information on the basis of the existing power grid. It puts forward higher requirements for reliability and controllability of information communication, and all kinds of business QoS of the backbone network. So the research of business QoS and trustworthy and controllable strategies mechanism have an important significance for the development of energy internet. This paper mainly studies how to use the software defined network (SDN) to achieve business QoS, and provide QoS support for all kinds of business of the energy internet. Combined with the current development situation of the energy internet in our country, this paper researches the trustworthy and controllable strategies mechanism for energy internet, and proposes the transition scheme of the IPv6 credible network architecture based on SDN. This coordinates the contradiction between the growing demand for energy internet applications and the limitations of the energy internet technology itself.

Quality of services and quality of life from service providers' perspectives: analysis with focus groups.

PubMed

Jenaro, C; Vega, V; Flores, N; Cruz, M

2013-06-01

Concepts such as support, quality of life and quality of services are customary in services for people with intellectual disabilities. The identification of the different ways of conceiving, prioritising and implementing these concepts by service providers can help to drive changes to achieve better personal outcomes for this population. The current study aims to identify service providers' perceptions regarding the quality of life of their clients and the quality of services they provide. It also aims to identify similarities and differences of appraisals among professionals, and to identify associations between supports, quality of life and quality of services. Data were collected from 22 service providers who attended three focus groups (professionals, direct support staff, and managers) from whom 424 comments were analysed. Service providers were asked about the required support for users, the meaning of quality of life for those users, and about features that should characterise quality services. Thematic analysis was employed and transcripts of the sessions were coded according to the dimensions of models on supports, quality of life and quality of services. Chi-squared tests were utilised to test for potential differences among groups. Each professional group has its own priorities concerning required supports. Among the organisation different and potentially conflicting perceptions regarding the meaning of experiencing quality of life coexist. Concerning quality of services, only managers mentioned personal outcomes. Finally, institutionalisation has a negative impact on supports, quality of life and quality of services. It is necessary to move beyond a shared awareness of the negative impact of institutionalisation towards the transformation of services in search of personal quality outcomes. © 2012 The Authors. Journal of Intellectual Disability Research © 2012 John Wiley & Sons Ltd, MENCAP & IASSID.

Pricing the Services in Dynamic Environment: Agent Pricing Model

NASA Astrophysics Data System (ADS)

Žagar, Drago; Rupčić, Slavko; Rimac-Drlje, Snježana

New Internet applications and services as well as new user demands open many new issues concerning dynamic management of quality of service and price for received service, respectively. The main goals of Internet service providers are to maximize profit and maintain a negotiated quality of service. From the users' perspective the main goal is to maximize ratio of received QoS and costs of service. However, achieving these objectives could become very complex if we know that Internet service users might during the session become highly dynamic and proactive. This connotes changes in user profile or network provider/s profile caused by high level of user mobility or variable level of user demands. This paper proposes a new agent based pricing architecture for serving the highly dynamic customers in context of dynamic user/network environment. The proposed architecture comprises main aspects and basic parameters that will enable objective and transparent assessment of the costs for the service those Internet users receive while dynamically change QoS demands and cost profile.

Optimal Resource Allocation under Fair QoS in Multi-tier Server Systems

NASA Astrophysics Data System (ADS)

Akai, Hirokazu; Ushio, Toshimitsu; Hayashi, Naoki

Recent development of network technology realizes multi-tier server systems, where several tiers perform functionally different processing requested by clients. It is an important issue to allocate resources of the systems to clients dynamically based on their current requests. On the other hand, Q-RAM has been proposed for resource allocation in real-time systems. In the server systems, it is important that execution results of all applications requested by clients are the same QoS(quality of service) level. In this paper, we extend Q-RAM to multi-tier server systems and propose a method for optimal resource allocation with fairness of the QoS levels of clients’ requests. We also consider an assignment problem of physical machines to be sleep in each tier sothat the energy consumption is minimized.

Optimizing Multiple QoS for Workflow Applications using PSO and Min-Max Strategy

NASA Astrophysics Data System (ADS)

Umar Ambursa, Faruku; Latip, Rohaya; Abdullah, Azizol; Subramaniam, Shamala

2017-08-01

Workflow scheduling under multiple QoS constraints is a complicated optimization problem. Metaheuristic techniques are excellent approaches used in dealing with such problem. Many metaheuristic based algorithms have been proposed, that considers various economic and trustworthy QoS dimensions. However, most of these approaches lead to high violation of user-defined QoS requirements in tight situation. Recently, a new Particle Swarm Optimization (PSO)-based QoS-aware workflow scheduling strategy (LAPSO) is proposed to improve performance in such situations. LAPSO algorithm is designed based on synergy between a violation handling method and a hybrid of PSO and min-max heuristic. Simulation results showed a great potential of LAPSO algorithm to handling user requirements even in tight situations. In this paper, the performance of the algorithm is anlysed further. Specifically, the impact of the min-max strategy on the performance of the algorithm is revealed. This is achieved by removing the violation handling from the operation of the algorithm. The results show that LAPSO based on only the min-max method still outperforms the benchmark, even though the LAPSO with the violation handling performs more significantly better.

Power-efficient distributed resource allocation under goodput QoS constraints for heterogeneous networks

NASA Astrophysics Data System (ADS)

Andreotti, Riccardo; Del Fiorentino, Paolo; Giannetti, Filippo; Lottici, Vincenzo

2016-12-01

This work proposes a distributed resource allocation (RA) algorithm for packet bit-interleaved coded OFDM transmissions in the uplink of heterogeneous networks (HetNets), characterized by small cells deployed over a macrocell area and sharing the same band. Every user allocates its transmission resources, i.e., bits per active subcarrier, coding rate, and power per subcarrier, to minimize the power consumption while both guaranteeing a target quality of service (QoS) and accounting for the interference inflicted by other users transmitting over the same band. The QoS consists of the number of information bits delivered in error-free packets per unit of time, or goodput (GP), estimated at the transmitter by resorting to an efficient effective SNR mapping technique. First, the RA problem is solved in the point-to-point case, thus deriving an approximate yet accurate closed-form expression for the power allocation (PA). Then, the interference-limited HetNet case is examined, where the RA problem is described as a non-cooperative game, providing a solution in terms of generalized Nash equilibrium. Thanks to the closed-form of the PA, the solution analysis is based on the best response concept. Hence, sufficient conditions for existence and uniqueness of the solution are analytically derived, along with a distributed algorithm capable of reaching the game equilibrium.

Chip-set for quality of service support in passive optical networks

NASA Astrophysics Data System (ADS)

Ringoot, Edwin; Hoebeke, Rudy; Slabbinck, B. Hans; Verhaert, Michel

1998-10-01

In this paper the design of a chip-set for QoS provisioning in ATM-based Passive Optical Networks is discussed. The implementation of a general-purpose switch chip on the Optical Network Unit is presented, with focus on the design of the cell scheduling and buffer management logic. The cell scheduling logic supports `colored' grants, priority jumping and weighted round-robin scheduling. The switch chip offers powerful buffer management capabilities enabling the efficient support of GFR and UBR services. Multicast forwarding is also supported. In addition, the architecture of a MAC controller chip developed for a SuperPON access network is introduced. In particular, the permit scheduling logic and its implementation on the Optical Line Termination will be discussed. The chip-set enables the efficient support of services with different service requirements on the SuperPON. The permit scheduling logic built into the MAC controller chip in combination with the cell scheduling and buffer management capabilities of the switch chip can be used by network operators to offer guaranteed service performance to delay sensitive services, and to efficiently and fairly distribute any spare capacity to delay insensitive services.

Two Phase Admission Control for QoS Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Chen, Chien-Sheng; Su, Yi-Wen; Liu, Wen-Hsiung; Chi, Ching-Lung

In this paper a novel and effective two phase admission control (TPAC) for QoS mobile ad hoc networks is proposed that satisfies the real-time traffic requirements in mobile ad hoc networks. With a limited amount of extra overhead, TPAC can avoid network congestions by a simple and precise admission control which blocks most of the overloading flow-requests in the route discovery process. When compared with previous QoS routing schemes such as QoS-aware routing protocol and CACP protocols, it is shown from system simulations that the proposed scheme can increase the system throughput and reduce both the dropping rate and the end-to-end delay. Therefore, TPAC is surely an effective QoS-guarantee protocol to provide for real-time traffic.

Steering healthcare service delivery: a regulatory perspective.

PubMed

Prakash, Gyan

2015-01-01

The purpose of this paper is to explore regulation in India's healthcare sector and makes recommendations needed for enhancing the healthcare service. The literature was reviewed to understand healthcare's regulatory context. To understand the current healthcare system, qualitative data were collected from state-level officials, public and private hospital staff. A patient survey was performed to assess service quality (QoS). Regulation plays a central role in driving healthcare QoS. India needs to strengthen market and institutional co-production based approaches for steering its healthcare in which delivery processes are complex and pose different challenges. This study assesses current healthcare regulation in an Indian state and presents a framework for studying and strengthening regulation. Agile regulation should be based on service delivery issues (pull approach) rather than monitoring and sanctions based regulatory environment (push approach). Healthcare pitfalls across the world seem to follow similar follies. India's complexity and experience is useful for emerging and developed economies. The author reviewed around 70 publications and synthesised them in healthcare regulatory contexts. Patient's perception of private providers could be a key input towards steering regulation. Identifying gaps across QoS dimensions would be useful in taking corrective measures.

Probabilistic QoS Analysis In Wireless Sensor Networks

DTIC Science & Technology

2012-04-01

and A.O. Fapojuwo. TDMA scheduling with optimized energy efficiency and minimum delay in clustered wireless sensor networks . IEEE Trans. on Mobile...Research Computer Science and Engineering, Department of 5-1-2012 Probabilistic QoS Analysis in Wireless Sensor Networks Yunbo Wang University of...Wang, Yunbo, "Probabilistic QoS Analysis in Wireless Sensor Networks " (2012). Computer Science and Engineering: Theses, Dissertations, and Student

Implementation of QoSS (Quality-of-Security Service) for NoC-Based SoC Protection

NASA Astrophysics Data System (ADS)

Sepúlveda, Johanna; Pires, Ricardo; Strum, Marius; Chau, Wang Jiang

Many of the current electronic systems embedded in a SoC (System-on-Chip) are used to capture, store, manipulate and access critical data, as well as to perform other key functions. In such a scenario, security is considered as an important issue. The Network-on-chip (NoC), as the foreseen communication structure of next-generation SoC devices, can be used to efficiently incorporate security. Our work proposes the implementation of QoSS (Quality of Security Service) to overcome present SoC vulnerabilities. QoSS is a novel concept for data protection that introduces security as a dimension of QoS. In this paper, we present the implementation of two security services (access control and authentication), that may be configured to assume one from several possible levels, the implementation of a technique to avoid denial-of-service (DoS) attacks, evaluate their effectiveness and estimate their impact on NoC performance.

Modified weighted fair queuing for packet scheduling in mobile WiMAX networks

NASA Astrophysics Data System (ADS)

Satrya, Gandeva B.; Brotoharsono, Tri

2013-03-01

The increase of user mobility and the need for data access anytime also increases the interest in broadband wireless access (BWA). The best available quality of experience for mobile data service users are assured for IEEE 802.16e based users. The main problem of assuring a high QOS value is how to allocate available resources among users in order to meet the QOS requirement for criteria such as delay, throughput, packet loss and fairness. There is no specific standard scheduling mechanism stated by IEEE standards, which leaves it for implementer differentiation. There are five QOS service classes defined by IEEE 802.16: Unsolicited Grant Scheme (UGS), Extended Real Time Polling Service (ertPS), Real Time Polling Service (rtPS), Non Real Time Polling Service (nrtPS) and Best Effort Service (BE). Each class has different QOS parameter requirements for throughput and delay/jitter constraints. This paper proposes Modified Weighted Fair Queuing (MWFQ) scheduling scenario which was based on Weighted Round Robin (WRR) and Weighted Fair Queuing (WFQ). The performance of MWFQ was assessed by using above five QoS criteria. The simulation shows that using the concept of total packet size calculation improves the network's performance.

Dynamic composition of medical support services in the ICU: Platform and algorithm design details.

PubMed

Hristoskova, Anna; Moeyersoon, Dieter; Van Hoecke, Sofie; Verstichel, Stijn; Decruyenaere, Johan; De Turck, Filip

2010-12-01

The Intensive Care Unit (ICU) is an extremely data-intensive environment where each patient needs to be monitored 24/7. Bedside monitors continuously register vital patient values (such as serum creatinine, systolic blood pressure) which are recorded frequently in the hospital database (e.g. every 2 min in the ICU of the Ghent University Hospital), laboratories generate hundreds of results of blood and urine samples, and nurses measure blood pressure and temperature up to 4 times an hour. The processing of such large amount of data requires an automated system to support the physicians' daily work. The Intensive Care Service Platform (ICSP) offers the needed support through the development of medical support services for processing and monitoring patients' data. With an increased deployment of these medical support services, reusing existing services as building blocks to create new services offers flexibility to the developer and accelerates the design process. This paper presents a new addition to the ICSP, the Dynamic Composer for Web services. Based on a semantic description of the medical support services, this Composer enables a service to be executed by creating a composition of medical services that provide the needed calculations. The composition is achieved using various algorithms satisfying certain quality of service (QoS) constraints and requirements. In addition to the automatic composition the paper also proposes a recovery mechanism in case of unavailable services. When executing the composition of medical services, unavailable services are dynamically replaced by equivalent services or a new composition achieving the same result. The presented platform and QoS algorithms are put through extensive performance and scalability tests for typical ICU scenarios, in which basic medical services are composed to a complex patient monitoring service. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

A QoS Management Technique of Urgent Information Provision in ITS Services Using DSRC for Autonomous Base Stations

NASA Astrophysics Data System (ADS)

Shimura, Akitoshi; Aizono, Takeiki; Hiraiwa, Masashi; Sugano, Shigeki

A QoS management technique based on an autonomous decentralized mobility system, which is an autonomous decentralized system enhanced to provide mobile stations with information about urgent roadway situations, is proposed in this paper. This technique enables urgent messages to be flexibly and quickly transmitted to mobile stations by multiple decentralized base stations using dedicated short range communication. It also supports the easy addition of additional base stations. Each station autonomously creates information-delivery communities based on the urgency of the messages it receives through the roadside network and the distances between the senders and receivers. Each station dynamically determines the urgency of messages according to the message content and the speed of the mobile stations. Evaluation of this technique applied to the Smart Gateway system, which provides driving-assistance services to mobile stations through dedicated short-range communication, demonstrated its effectiveness and that it is suitable for actual systems.

Cross-Layer Algorithms for QoS Enhancement in Wireless Multimedia Sensor Networks

NASA Astrophysics Data System (ADS)

Saxena, Navrati; Roy, Abhishek; Shin, Jitae

A lot of emerging applications like advanced telemedicine and surveillance systems, demand sensors to deliver multimedia content with precise level of QoS enhancement. Minimizing energy in sensor networks has been a much explored research area but guaranteeing QoS over sensor networks still remains an open issue. In this letter we propose a cross-layer approach combining Network and MAC layers, for QoS enhancement in wireless multimedia sensor networks. In the network layer a statistical estimate of sensory QoS parameters is performed and a nearoptimal genetic algorithmic solution is proposed to solve the NP-complete QoS-routing problem. On the other hand the objective of the proposed MAC algorithm is to perform the QoS-based packet classification and automatic adaptation of the contention window. Simulation results demonstrate that the proposed protocol is capable of providing lower delay and better throughput, at the cost of reasonable energy consumption, in comparison with other existing sensory QoS protocols.

Effect of self-reported quality of sleep on mobility in older adults.

PubMed

Malinowska, Katarzyna B; Okura, Mika; Ogita, Mihoko; Yamamoto, Miki; Nakai, Toshimi; Numata, Tomoko; Tsuboyama, Tadao; Arai, Hidenori

2016-02-01

Quality of sleep (QOS) has been shown to have an affect on mental and physical well-being, and quality of life. However, few studies have investigated how sleep affects mobility in older adults. The aim of the present study was to examine the relationship between QOS and mobility disorder (MD) in community-dwelling older adults. Data collected through self-administered questionnaires was analyzed for 4564 Japanese older adults. Sleep outcomes included two self-reported questions regarding QOS. Logistic regression analysis was used to analyze the association between sleep and MD both by the QOS questions independently and grouped together by the two QOS questions into three groups: often sleeps well and good awakening (GG), does not often sleep well and bad awakening (BB) and a group with one of each (GB/BG). After adjustment for age, sex and depression, both those who did not often sleep well and those with poor awakening were more likely to show MD (OR 1.45, 95% CI 1.29-1.75), (OR 1.77, 95% CI 1.50-2.08), respectively. When grouped by both questions, those in the BB group had the least favorable outcome with increased odds ratio for possessing a MD (OR 1.95, 95% CI 1.61-2.37), compared with GB group (OR 1.40, 95% CI 1.18-1.67). Often sleeping well and good morning awakening were both associated with MD, suggesting that self reported QOS is associated with MD. Further research is required to investigate whether improving sleep quality could be a possible means of preventing and reversing MD in older adults. © 2015 Japan Geriatrics Society.

IDMA-Based MAC Protocol for Satellite Networks with Consideration on Channel Quality

PubMed Central

2014-01-01

In order to overcome the shortcomings of existing medium access control (MAC) protocols based on TDMA or CDMA in satellite networks, interleave division multiple access (IDMA) technique is introduced into satellite communication networks. Therefore, a novel wide-band IDMA MAC protocol based on channel quality is proposed in this paper, consisting of a dynamic power allocation algorithm, a rate adaptation algorithm, and a call admission control (CAC) scheme. Firstly, the power allocation algorithm combining the technique of IDMA SINR-evolution and channel quality prediction is developed to guarantee high power efficiency even in terrible channel conditions. Secondly, the effective rate adaptation algorithm, based on accurate channel information per timeslot and by the means of rate degradation, can be realized. What is more, based on channel quality prediction, the CAC scheme, combining the new power allocation algorithm, rate scheduling, and buffering strategies together, is proposed for the emerging IDMA systems, which can support a variety of traffic types, and offering quality of service (QoS) requirements corresponding to different priority levels. Simulation results show that the new wide-band IDMA MAC protocol can make accurate estimation of available resource considering the effect of multiuser detection (MUD) and QoS requirements of multimedia traffic, leading to low outage probability as well as high overall system throughput. PMID:25126592

Research of three level match method about semantic web service based on ontology

NASA Astrophysics Data System (ADS)

Xiao, Jie; Cai, Fang

2011-10-01

An important step of Web service Application is the discovery of useful services. Keywords are used in service discovery in traditional technology like UDDI and WSDL, with the disadvantage of user intervention, lack of semantic description and low accuracy. To cope with these problems, OWL-S is introduced and extended with QoS attributes to describe the attribute and functions of Web Services. A three-level service matching algorithm based on ontology and QOS in proposed in this paper. Our algorithm can match web service by utilizing the service profile, QoS parameters together with input and output of the service. Simulation results shows that it greatly enhanced the speed of service matching while high accuracy is also guaranteed.

Phoenix: SOA based information management services

NASA Astrophysics Data System (ADS)

Grant, Rob; Combs, Vaughn; Hanna, Jim; Lipa, Brian; Reilly, Jim

2009-05-01

The Air Force Research Laboratory (AFRL) has developed a reference set of Information Management (IM) Services that will provide an essential piece of the envisioned final Net-Centric IM solution for the Department of Defense (DoD). These IM Services will provide mission critical functionality to enable seamless interoperability between existing and future DoD systems and services while maintaining a highly available IM capability across the wide spectrum of differing scalability and performance requirements. AFRL designed this set of IM Services for integration with other DoD and commercial SOA environments. The services developed will provide capabilities for information submission, information brokering and discovery, repository, query, type management, dissemination, session management, authorization, service brokering and event notification. In addition, the IM services support common information models that facilitate the management and dissemination of information consistent with client needs and established policy. The services support flexible and extensible definitions of session, service, and channel contexts that enable the application of Quality of Service (QoS) and security policies at many levels within the SOA.

Quality of service routing in wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Sane, Sachin J.; Patcha, Animesh; Mishra, Amitabh

2003-08-01

An efficient routing protocol is essential to guarantee application level quality of service running on wireless ad hoc networks. In this paper we propose a novel routing algorithm that computes a path between a source and a destination by considering several important constraints such as path-life, availability of sufficient energy as well as buffer space in each of the nodes on the path between the source and destination. The algorithm chooses the best path from among the multiples paths that it computes between two endpoints. We consider the use of control packets that run at a priority higher than the data packets in determining the multiple paths. The paper also examines the impact of different schedulers such as weighted fair queuing, and weighted random early detection among others in preserving the QoS level guarantees. Our extensive simulation results indicate that the algorithm improves the overall lifetime of a network, reduces the number of dropped packets, and decreases the end-to-end delay for real-time voice application.

Data on the key performance indicators for quality of service of GSM networks in Nigeria.

PubMed

Popoola, Segun I; Atayero, Aderemi A; Faruk, Nasir; Badejo, Joke A

2018-02-01

In this data article, the Key Performance Indicators (KPIs) for Quality of Service (QoS) of Global System for Mobile Communications (GSM) networks in Nigeria are provided and analyzed. The data provided in this paper contain the Call Setup Success Rate (CSSR), Drop Call Rate (DCR), Stand-alone Dedicated Channel (SDCCH) congestion, and Traffic Channel (TCH) congestion for the four GSM network operators in Nigeria (Airtel, Etisalat, Glo, and MTN). These comprehensive data were obtained from the Nigerian Communications Commission (NCC). Significant differences in each of the KPIs for the four quarters of each year were presented based on Analysis of Variance (ANOVA). The values of the KPIs were plotted against the months of the year for better visualization and understanding of data trends across the four quarters. Multiple comparisons of the mean-quarterly differences of the KPIs were also presented using Tukey's Post Hoc test. Public availability and further interpretation and discussion of these useful information will assist the network providers, Nigerian government, local and international regulatory bodies, policy makers, and other stakeholders in ensuring access of people, machines, and things to high quality telecommunications services.

Using Modeling and Simulation to Examine the Benefits of a Network Tasking Order

DTIC Science & Technology

2010-01-01

Without careful planning, the topolo- gies that form can suffer from poor Quality of Service (QoS). The networks could have bottlenecks, or worse, be... quality of service Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to...mission type include: • expected communications partners; • type of data transmitted; • bandwidth required (average, burst); • quality of service

National Water Quality Laboratory, 1995 services catalog

USGS Publications Warehouse

Timme, P.J.

1995-01-01

This Services Catalog contains information about field supplies and analytical services available from the National Water Quality Laboratory in Denver, Colo., and field supplies available from the Quality Water Service Unit in Ocala, Fla., to members of the U.S. Geological Survey. To assist personnel in the selection of analytical services, this catalog lists sample volume, required containers, applicable concentration range, detection level, precision of analysis, and preservation requirements for samples.

Maximization of the Supportable Number of Sensors in QoS-Aware Cluster-Based Underwater Acoustic Sensor Networks

PubMed Central

Nguyen, Thi-Tham; Van Le, Duc; Yoon, Seokhoon

2014-01-01

This paper proposes a practical low-complexity MAC (medium access control) scheme for quality of service (QoS)-aware and cluster-based underwater acoustic sensor networks (UASN), in which the provision of differentiated QoS is required. In such a network, underwater sensors (U-sensor) in a cluster are divided into several classes, each of which has a different QoS requirement. The major problem considered in this paper is the maximization of the number of nodes that a cluster can accommodate while still providing the required QoS for each class in terms of the PDR (packet delivery ratio). In order to address the problem, we first estimate the packet delivery probability (PDP) and use it to formulate an optimization problem to determine the optimal value of the maximum packet retransmissions for each QoS class. The custom greedy and interior-point algorithms are used to find the optimal solutions, which are verified by extensive simulations. The simulation results show that, by solving the proposed optimization problem, the supportable number of underwater sensor nodes can be maximized while satisfying the QoS requirements for each class. PMID:24608009

Maximization of the supportable number of sensors in QoS-aware cluster-based underwater acoustic sensor networks.

PubMed

Nguyen, Thi-Tham; Le, Duc Van; Yoon, Seokhoon

2014-03-07

This paper proposes a practical low-complexity MAC (medium access control) scheme for quality of service (QoS)-aware and cluster-based underwater acoustic sensor networks (UASN), in which the provision of differentiated QoS is required. In such a network, underwater sensors (U-sensor) in a cluster are divided into several classes, each of which has a different QoS requirement. The major problem considered in this paper is the maximization of the number of nodes that a cluster can accommodate while still providing the required QoS for each class in terms of the PDR (packet delivery ratio). In order to address the problem, we first estimate the packet delivery probability (PDP) and use it to formulate an optimization problem to determine the optimal value of the maximum packet retransmissions for each QoS class. The custom greedy and interior-point algorithms are used to find the optimal solutions, which are verified by extensive simulations. The simulation results show that, by solving the proposed optimization problem, the supportable number of underwater sensor nodes can be maximized while satisfying the QoS requirements for each class.

Agent-Based Framework for Personalized Service Provisioning in Converged IP Networks

NASA Astrophysics Data System (ADS)

Podobnik, Vedran; Matijasevic, Maja; Lovrek, Ignac; Skorin-Kapov, Lea; Desic, Sasa

In a global multi-service and multi-provider market, the Internet Service Providers will increasingly need to differentiate in the service quality they offer and base their operation on new, consumer-centric business models. In this paper, we propose an agent-based framework for the Business-to-Consumer (B2C) electronic market, comprising the Consumer Agents, Broker Agents and Content Agents, which enable Internet consumers to select a content provider in an automated manner. We also discuss how to dynamically allocate network resources to provide end-to-end Quality of Service (QoS) for a given consumer and content provider.

GUEST EDITORS' INTRODUCTION: Guest Editors' introduction

NASA Astrophysics Data System (ADS)

Coulson, Geoff; de Meer, Jan B.

1997-03-01

Quality of Service (QoS) has emerged in the last few years as a topical and challenging research area in distributed systems. For a broad definition of QoS we refer to the ISO's Reference Model for Open Distributed Processing (ISO/IEC IS 10746-2): `The notion of QoS is a system or object property, and consists of a set of quality requirements on the collective behaviour of one or more objects . . .'. In the context of this special issue, QoS is primarily associated with systems such as distributed multimedia application platforms or distributed simulations. The QoS requirements of such systems typically relate to measures of rate and latency of information transfer, probability of a communication being disrupted, probability of system failure, probability of storage failure, etc. The role of QoS management is thus to ensure that applications are able to specify and obtain the quality of service that they require for their correct execution. In general, the functions of QoS management may be subsumed under the following headings: (i) QoS specification and mapping, (ii) QoS negotiation, resource allocation and admission control and (iii) QoS monitoring, adaptation and renegotiation. QoS specification defines the QoS required by an application in terms of both timeliness constraints and guarantees. QoS mapping then translates between QoS representations at different system levels, relieving the user of the necessity of thinking in terms of low-level QoS representations. For example, a user may express a jitter requirement by manipulating a slider in a GUI, and this could be mapped at the lower layers into a requirement for an absolute bound on ATM cell jitter and a jitter smoothing buffer of a certain size. QoS negotiation, resource allocation and admission control are collectively responsible for configuring a system in preparation for the execution of a QoS requiring application. QoS negotiation provides a framework in which the QoS levels supported by individual

Cascaded neural networks for sequenced propagation estimation, multiuser detection, and adaptive radio resource control of third-generation wireless networks for multimedia services

NASA Astrophysics Data System (ADS)

Hortos, William S.

1999-03-01

A hybrid neural network approach is presented to estimate radio propagation characteristics and multiuser interference and to evaluate their combined impact on throughput, latency and information loss in third-generation (3G) wireless networks. The latter three performance parameters influence the quality of service (QoS) for multimedia services under consideration for 3G networks. These networks, based on a hierarchical architecture of overlaying macrocells on top of micro- and picocells, are planned to operate in mobile urban and indoor environments with service demands emanating from circuit-switched, packet-switched and satellite-based traffic sources. Candidate radio interfaces for these networks employ a form of wideband CDMA in 5-MHz and wider-bandwidth channels, with possible asynchronous operation of the mobile subscribers. The proposed neural network (NN) architecture allocates network resources to optimize QoS metrics. Parameters of the radio propagation channel are estimated, followed by control of an adaptive antenna array at the base station to minimize interference, and then joint multiuser detection is performed at the base station receiver. These adaptive processing stages are implemented as a sequence of NN techniques that provide their estimates as inputs to a final- stage Kohonen self-organizing feature map (SOFM). The SOFM optimizes the allocation of available network resources to satisfy QoS requirements for variable-rate voice, data and video services. As the first stage of the sequence, a modified feed-forward multilayer perceptron NN is trained on the pilot signals of the mobile subscribers to estimate the parameters of shadowing, multipath fading and delays on the uplinks. A recurrent NN (RNN) forms the second stage to control base stations' adaptive antenna arrays to minimize intra-cell interference. The third stage is based on a Hopfield NN (HNN), modified to detect multiple users on the uplink radio channels to mitigate multiaccess

Performance and Challenges of Service-Oriented Architecture for Wireless Sensor Networks.

PubMed

Alshinina, Remah; Elleithy, Khaled

2017-03-08

Wireless Sensor Networks (WSNs) have become essential components for a variety of environmental, surveillance, military, traffic control, and healthcare applications. These applications face critical challenges such as communication, security, power consumption, data aggregation, heterogeneities of sensor hardware, and Quality of Service (QoS) issues. Service-Oriented Architecture (SOA) is a software architecture that can be integrated with WSN applications to address those challenges. The SOA middleware bridges the gap between the high-level requirements of different applications and the hardware constraints of WSNs. This survey explores state-of-the-art approaches based on SOA and Service-Oriented Middleware (SOM) architecture that provide solutions for WSN challenges. The categories of this paper are based on approaches of SOA with and without middleware for WSNs. Additionally, features of SOA and middleware architectures for WSNs are compared to achieve more robust and efficient network performance. Design issues of SOA middleware for WSNs and its characteristics are also highlighted. The paper concludes with future research directions in SOM architecture to meet all requirements of emerging application of WSNs.

Performance and Challenges of Service-Oriented Architecture for Wireless Sensor Networks

PubMed Central

Alshinina, Remah; Elleithy, Khaled

2017-01-01

Wireless Sensor Networks (WSNs) have become essential components for a variety of environmental, surveillance, military, traffic control, and healthcare applications. These applications face critical challenges such as communication, security, power consumption, data aggregation, heterogeneities of sensor hardware, and Quality of Service (QoS) issues. Service-Oriented Architecture (SOA) is a software architecture that can be integrated with WSN applications to address those challenges. The SOA middleware bridges the gap between the high-level requirements of different applications and the hardware constraints of WSNs. This survey explores state-of-the-art approaches based on SOA and Service-Oriented Middleware (SOM) architecture that provide solutions for WSN challenges. The categories of this paper are based on approaches of SOA with and without middleware for WSNs. Additionally, features of SOA and middleware architectures for WSNs are compared to achieve more robust and efficient network performance. Design issues of SOA middleware for WSNs and its characteristics are also highlighted. The paper concludes with future research directions in SOM architecture to meet all requirements of emerging application of WSNs. PMID:28282896

7 CFR 160.11 - Quality requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Quality requirements. 160.11 Section 160.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... STANDARDS FOR NAVAL STORES General § 160.11 Quality requirements. The several standards for spirits of...

An Adaptive QoS Routing Solution for MANET Based Multimedia Communications in Emergency Cases

NASA Astrophysics Data System (ADS)

Ramrekha, Tipu Arvind; Politis, Christos

The Mobile Ad hoc Networks (MANET) is a wireless network deprived of any fixed central authoritative routing entity. It relies entirely on collaborating nodes forwarding packets from source to destination. This paper describes the design, implementation and performance evaluation of CHAMELEON, an adaptive Quality of Service (QoS) routing solution, with improved delay and jitter performances, enabling multimedia communication for MANETs in extreme emergency situations such as forest fire and terrorist attacks as defined in the PEACE project. CHAMELEON is designed to adapt its routing behaviour according to the size of a MANET. The reactive Ad Hoc on-Demand Distance Vector Routing (AODV) and proactive Optimized Link State Routing (OLSR) protocols are deemed appropriate for CHAMELEON through their performance evaluation in terms of delay and jitter for different MANET sizes in a building fire emergency scenario. CHAMELEON is then implemented in NS-2 and evaluated similarly. The paper concludes with a summary of findings so far and intended future work.

Blocking probability in the hose-model optical VPN with different number of wavelengths

NASA Astrophysics Data System (ADS)

Roslyakov, Alexander V.

2017-04-01

Connection setup with guaranteed quality of service (QoS) in the optical virtual private network (OVPN) is a major goal for the network providers. In order to support this we propose a QoS based OVPN connection set up mechanism over WDM network to the end customer. The proposed WDM network model can be specified in terms of QoS parameter such as blocking probability. We estimated this QoS parameter based on the hose-model OVPN. In this mechanism the OVPN connections also can be created or deleted according to the availability of the wavelengths in the optical path. In this paper we have considered the impact of the number of wavelengths on the computation of blocking probability. The goal of the work is to dynamically provide a best OVPN connection during frequent arrival of connection requests with QoS requirements.

7 CFR 58.530 - Keeping quality requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Requirements for Cottage Cheese Bearing Usda Official Identification § 58.530 Keeping quality requirements. Keeping quality...

Taxonomy for and Analysis of Anonymous Communications Networks

DTIC Science & Technology

2009-03-01

Privacy QI Quasi-Identifier QoS Quality -of- Service RA Receiver Anonymity RFC Request For Comments RREQ Route Request RREP Route Reply...particular message as a measure. This amounts to the sender specifying a Quality -of- Service (QoS) threshold for anonymity services depending on...Location-Based Services Through Spatial and Temporal Cloaking," Proceedings of the Proceedings of MobiSys 2003: The 1st International Conference on

A new scheduling algorithm to provide proportional QoS in optical burst switching networks

NASA Astrophysics Data System (ADS)

Tan, Wei; Luo, Yunhan; Wang, Sheng; Xu, Du; Pan, Yonghong; Li, Lemin

2005-02-01

A new scheduling algorithm, which aims to provide proportional and controllable QoS in terms of burst loss probability for OBS (optical burst switching) networks, is proposed on the basis of a summary of current QoS schemes in OBS. With simulations, performance analyses and comparisons are studied in detail. The results show that, in the proposed scheme, burst loss probabilities are proportional to the given factors and the control of QoS performance can be achieved with better performance. This scheme will be beneficial to the OBS network management and the tariff policy making.

Technology usage, quality management system, and service quality in Thailand.

PubMed

Sivabrovornvatana, Nilubon; Siengthai, Sununta; Krairit, Donyaprueth; Paul, Himangshu

2005-01-01

This article aims to explore the relationship between technology and quality management for enhancing Thai hospital service quality. The paper presents the findings of an exploratory study that investigates service quality from the customer and service provider perception. In-depth interviews were conducted with respondents in Thai hospitals. The interviews explored service-related factors that patients and service providers perceive to be important for hospital services. The first interview group consisted of professionals as internal customers in direct contact with external customers, while the second group consisted of external customers of the same hospitals. The study's outcomes clearly suggest factors that make significant contribution to service quality. These factors can be categorized according to five SERVQUAL dimensions (reliability, responsiveness, assurance, empathy, and tangibility), although some factors required slightly different interpretation. The findings suggest that hospitals can develop an appropriate approach to their advantage, which can yield sustainable improvement in service quality as perceived by patients and professionals. Hospitals can make better quality decisions based on structured measurement and knowledge. It is recommended that managers apply this knowledge for successful implementation of activities related to service quality in their organizations.

Link Power Budget and Traffict QoS Performance Analysis of Gygabit Passive Optical Network

NASA Astrophysics Data System (ADS)

Ubaidillah, A.; Alfita, R.; Toyyibah

2018-01-01

Data service of telecommunication network is needed widely in the world; therefore extra wide bandwidth must be provided. For this case, PT. Telekomunikasi Tbk. applies GPON (Gigabit Passive Optical Network) as optical fibre based on telecommunication network system. GPON is a point to a multipoint technology of FTTx (Fiber to The x) that transmits information signals to the subscriber over optical fibre. In GPON trunking system, from OLT (Optical Line Terminal), the network is split to many ONT (Optical Network Terminal) of the subscribers, so it causes path loss and attenuation. In this research, the GPON performance is measured from the link power budget system and the Quality of Service (QoS) of the traffic. And the observation result shows that the link power budget system of this GPON is in good condition. The link power budget values from the mathematical calculation and direct measurement are satisfy the ITU-T G984 Class B standard, that the power level must be between -8 dBm to -27 dBm. While from the traffic performance, the observation result shows that the network resource utility of the subscribers of the observed area is not optimum. The mean of subscriber utility rate is 27.985 bps for upstream and 79.687 bps for downstream. While maximally, It should be 60.800 bps for upstream and 486.400 bps for downstream.

Dynamic Online Bandwidth Adjustment Scheme Based on Kalai-Smorodinsky Bargaining Solution

NASA Astrophysics Data System (ADS)

Kim, Sungwook

Virtual Private Network (VPN) is a cost effective method to provide integrated multimedia services. Usually heterogeneous multimedia data can be categorized into different types according to the required Quality of Service (QoS). Therefore, VPN should support the prioritization among different services. In order to support multiple types of services with different QoS requirements, efficient bandwidth management algorithms are important issues. In this paper, I employ the Kalai-Smorodinsky Bargaining Solution (KSBS) for the development of an adaptive bandwidth adjustment algorithm. In addition, to effectively manage the bandwidth in VPNs, the proposed control paradigm is realized in a dynamic online approach, which is practical for real network operations. The simulations show that the proposed scheme can significantly improve the system performances.

Resource Provisioning in SLA-Based Cluster Computing

NASA Astrophysics Data System (ADS)

Xiong, Kaiqi; Suh, Sang

Cluster computing is excellent for parallel computation. It has become increasingly popular. In cluster computing, a service level agreement (SLA) is a set of quality of services (QoS) and a fee agreed between a customer and an application service provider. It plays an important role in an e-business application. An application service provider uses a set of cluster computing resources to support e-business applications subject to an SLA. In this paper, the QoS includes percentile response time and cluster utilization. We present an approach for resource provisioning in such an environment that minimizes the total cost of cluster computing resources used by an application service provider for an e-business application that often requires parallel computation for high service performance, availability, and reliability while satisfying a QoS and a fee negotiated between a customer and the application service provider. Simulation experiments demonstrate the applicability of the approach.

Policy-Based Middleware for QoS Management and Signaling in the Evolved Packet System

NASA Astrophysics Data System (ADS)

Good, Richard; Gouveia, Fabricio; Magedanz, Thomas; Ventura, Neco

The 3GPP are currently finalizing their Evolved Packet System (EPS) with the Evolved Packet Core (EPC) central to this framework. The EPC is a simplified, flat, all IP-based architecture that supports mobility between heterogeneous access networks and incorporates an evolved QoS concept based on the 3GPP Policy Control and Charging (PCC) framework. The IP Multimedia Subsystem (IMS) is an IP service element within the EPS, introduced for the rapid provisioning of innovative multimedia services. The evolved PCC framework extends the scope of operation and defines new interactions - in particular the S9 reference point is introduced to facilitate inter-domain PCC communication. This paper proposes an enhancement to the IMS/PCC framework that uses SIP routing information to discover signaling and media paths. This mechanism uses standardized IMS/PCC operations and allows applications to effectively issue resource requests from their home domain enabling QoS-connectivity across multiple domains. Because the mechanism operates at the service control layer it does not require any significant transport layer modifications or the sharing of potentially sensitive internal topology information. The evolved PCC architecture and inter-domain route discovery mechanisms were implemented in an evaluation testbed and performed favorably without adversely effecting end user experience.

Data forwarding mechanism for supporting real-time services during relocations in UMTS systems

NASA Astrophysics Data System (ADS)

Cai, Wei; Liao, Xianglong; Zheng, Liang; Liu, Zehong

2004-04-01

To minimize the interruption during the handovers or relocations invoked by subscribers moving is a very critical factor to enhance the performance of the UMTS systems. We know that the 2G systems have been optimized to minimize the interruption of speech during handovers by two main technologies: one is the bi-casting for the DL traffic and the other is the fast radio resynchronization by the UE for the UL traffic. In the UMTS systems, we have also implemented lossless relocations for non real-time services with high reliability by data buffering in the source RNC and target RNC for the UE. However, the UMTS systems support four QoS classes traffic flow: conversational class, streaming class, interactive class and background class. The main distinguishing factor between these QoS classes is how delay sensitive the traffic is: Conversational and Streaming classes are mainly used to carry real-time traffic flows, like video telephony, interactive and background classes are mainly used by traditional Internet applications like WWW, E-mail and FTP. It"s essential to provide the solutions for supporting real-time services to meet the requirement for QoS in UMTS systems. Apparently, the Data buffering mechanism is not adapted to real-time services because of it"s delay may exceed the basic requirement for real-time services. Under this background, the paper discussed two data forwarding solutions for real-time services from the PS domain in the UMTS systems: packet duplication and Core Network bi-casting. The former mechanism does not require any new procedures, messages nor information elements. The later mechanism requires that the GGSN or SGSN is able to bi-cast the DL traffic to the target RNC according to the relocations involving two SGSNs or just involving one SGSN. It also implicitly shows that we need change procedures at the nodes SGSN, GGSN and RNC which are involved in the relocation procedure based on existing procedures that we have already designed if

A measurement-driven approach to assess power line telecommunication (PLT) network quality of service (QoS) performance parameters

NASA Astrophysics Data System (ADS)

Betta, G.; Capriglione, D.; Ferrigno, L.; Laracca, M.

2009-10-01

Power line telecommunication (PLT) technology offers cheap and fast ways for providing in-home broadband services and local area networking. Its main advantage is due to the possibility of using the pre-existing electrical grid as a communication channel. Nevertheless, technical challenges arise from the difficulty of operating on a hostile medium, not designed for communication purposes, characterized by complex channel modeling and by varying time response. These aspects put practical problems for designers and testers in the assessment of network quality of service performance parameters such as the throughput, the latency, the jitter, and the reliability. The measurement of these parameters has not yet been standardized so that there do not exist reference test set-ups and measurement methodologies (i.e. the type of isolation from the ac main, the observation time and the number of experiments, the measurement uncertainty and so on). Consequently, experiments executed by adopting different methods may lead to incompatible measurement results, thus making it also impossible to have reliable comparisons of different PLT modems. Really, the development of standard procedures is a very difficult task because the scenarios in which the PLT modems can work are very wide and then the application of an exhaustive approach (in which all the parameters influencing the PLT performance should be considered) would be very complex and time consuming, thus making the modem characterization very expensive. In this paper, the authors propose a methodological approach to develop an efficient measurement procedure able to reliably assess the performance of PLT modems (in terms of network quality of service parameters) with a minimum number of experiments. It is based on both creating a reconfigurable grid to which real disturbing loads are connected and implementing an original design of the experiment technique based on the effects of the uncertainty of the measurement results

Cognitive Networks

DTIC Science & Technology

2007-06-15

13 2.1.3 Quality of Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2 Related Efforts...objectives such as resource management, Quality of Service (QoS), security, or access control. The limitations of CN applications should come from the...achieving the best mode of operation in an SDR. 2.1.3 Quality of Service There has been a lot of research on how to define a QoS architecture for the

Neural-tree call admission controller for ATM networks

NASA Astrophysics Data System (ADS)

Rughooputh, Harry C. S.

1999-03-01

Asynchronous Transfer Mode (ATM) has been recommended by ITU-T as the transport method for broadband integrated services digital networks. In high-speed ATM networks different types of multimedia traffic streams with widely varying traffic characteristics and Quality of Service (QoS) are asynchronously multiplexed on transmission links and switched without window flow control as found in X.25. In such an environment, a traffic control scheme is required to manage the required QoS of each class individually. To meet the QoS requirements, Bandwidth Allocation and Call Admission Control (CAC) in ATM networks must be able to adapt gracefully to the dynamic behavior of traffic and the time-varying nature of the network condition. In this paper, a Neural Network approach for CAC is proposed. The call admission problem is addressed by designing controllers based on Neural Tree Networks. Simulations reveal that the proposed scheme is not only simple but it also offers faster response than conventional neural/neuro-fuzzy controllers.

Operationalisation of service quality in household waste collection.

PubMed

Schulte, Nico Alexander; Gellenbeck, Klaus; Nelles, Michael

2017-04-01

Since 2007, there has been intensive discussion at European and national levels concerning the standardisation of services including those in the sector of waste management. The drafts of the European standard prEN 16250 and the German preliminary standard DIN SPEC 1108 are intended to establish a uniform definition of corresponding services and their (minimum) service levels. Their binding application in practice requires that systematic inspections be provided to ascertain to what degree a service has been carried out as agreed upon. However, both standardisation projects give only a few examples of potential quality characteristics and offer no concrete information concerning methods of measurement. Because intersectoral or cross-service quality inspections do not exist, there is a need for the development of specific quality inspections. The study introduced in this article examines the question of how the service quality of door-to-door waste collection can be systematically measured. To this end, the quality concept applied to the process of waste collection was first concretised and then operationalised using indicators. Based upon this, the methods of the quality inspections were developed and subjected to a trial of their applicability in a German waste management company. The methods for measuring and evaluating take into account, in addition to the different boundary conditions of collection, also the possible customer influence on the collection process and consequently on the service performed by the collection crew. In order to avoid time- and therefore cost-intensive exhaustive surveys, a multilevel random-controlled selection of survey units was developed, too. Based on the analysis of the measurement data, it was possible to determine specific time requirement values for the regular performance of the data surveys, as well as minimum sample sizes as a function of the number of container locations of the waste collection tours. On the basis of this

A Multiuser Manufacturing Resource Service Composition Method Based on the Bees Algorithm

PubMed Central

Xie, Yongquan; Zhou, Zude; Pham, Duc Truong; Xu, Wenjun; Ji, Chunqian

2015-01-01

In order to realize an optimal resource service allocation in current open and service-oriented manufacturing model, multiuser resource service composition (RSC) is modeled as a combinational and constrained multiobjective problem. The model takes into account both subjective and objective quality of service (QoS) properties as representatives to evaluate a solution. The QoS properties aggregation and evaluation techniques are based on existing researches. The basic Bees Algorithm is tailored for finding a near optimal solution to the model, since the basic version is only proposed to find a desired solution in continuous domain and thus not suitable for solving the problem modeled in our study. Particular rules are designed for handling the constraints and finding Pareto optimality. In addition, the established model introduces a trusted service set to each user so that the algorithm could start by searching in the neighbor of more reliable service chains (known as seeds) than those randomly generated. The advantages of these techniques are validated by experiments in terms of success rate, searching speed, ability of avoiding ingenuity, and so forth. The results demonstrate the effectiveness of the proposed method in handling multiuser RSC problems. PMID:26339232

Design of QoS-Aware Multi-Level MAC-Layer for Wireless Body Area Network.

PubMed

Hu, Long; Zhang, Yin; Feng, Dakui; Hassan, Mohammad Mehedi; Alelaiwi, Abdulhameed; Alamri, Atif

2015-12-01

With the advances in wearable computing and various wireless technologies, there is an increasing trend to outsource body signals from wireless body area network (WBAN) to outside world including cyber space, healthcare big data clouds, etc. Since the environmental and physiological data collected by multimodal sensors have different importance, the provisioning of quality of service (QoS) for the sensory data in WBAN is a critical issue. This paper proposes multiple level-based QoS design at WBAN media access control layer in terms of user level, data level and time level. In the proposed QoS provisioning scheme, different users have different priorities, various sensory data collected by different sensor nodes have different importance, while data priority for the same sensor node varies over time. The experimental results show that the proposed multi-level based QoS provisioning solution in WBAN yields better performance for meeting QoS requirements of personalized healthcare applications while achieving energy saving.

Optimal route discovery for soft QOS provisioning in mobile ad hoc multimedia networks

NASA Astrophysics Data System (ADS)

Huang, Lei; Pan, Feng

2007-09-01

In this paper, we propose an optimal routing discovery algorithm for ad hoc multimedia networks whose resource keeps changing, First, we use stochastic models to measure the network resource availability, based on the information about the location and moving pattern of the nodes, as well as the link conditions between neighboring nodes. Then, for a certain multimedia packet flow to be transmitted from a source to a destination, we formulate the optimal soft-QoS provisioning problem as to find the best route that maximize the probability of satisfying its desired QoS requirements in terms of the maximum delay constraints. Based on the stochastic network resource model, we developed three approaches to solve the formulated problem: A centralized approach serving as the theoretical reference, a distributed approach that is more suitable to practical real-time deployment, and a distributed dynamic approach that utilizes the updated time information to optimize the routing for each individual packet. Examples of numerical results demonstrated that using the route discovered by our distributed algorithm in a changing network environment, multimedia applications could achieve better QoS statistically.

E-Services quality assessment framework for collaborative networks

NASA Astrophysics Data System (ADS)

Stegaru, Georgiana; Danila, Cristian; Sacala, Ioan Stefan; Moisescu, Mihnea; Mihai Stanescu, Aurelian

2015-08-01

In a globalised networked economy, collaborative networks (CNs) are formed to take advantage of new business opportunities. Collaboration involves shared resources and capabilities, such as e-Services that can be dynamically composed to automate CN participants' business processes. Quality is essential for the success of business process automation. Current approaches mostly focus on quality of service (QoS)-based service selection and ranking algorithms, overlooking the process of service composition which requires interoperable, adaptable and secure e-Services to ensure seamless collaboration, data confidentiality and integrity. Lack of assessment of these quality attributes can result in e-Service composition failure. The quality of e-Service composition relies on the quality of each e-Service and on the quality of the composition process. Therefore, there is the need for a framework that addresses quality from both views: product and process. We propose a quality of e-Service composition (QoESC) framework for quality assessment of e-Service composition for CNs which comprises of a quality model for e-Service evaluation and guidelines for quality of e-Service composition process. We implemented a prototype considering a simplified telemedicine use case which involves a CN in e-Healthcare domain. To validate the proposed quality-driven framework, we analysed service composition reliability with and without using the proposed framework.

Research Challenges in Managing and Using Service Level Agreements

NASA Astrophysics Data System (ADS)

Rana, Omer; Ziegler, Wolfgang

A Service Level Agreement (SLA) represents an agreement between a service user and a provider in the context of a particular service provision. SLAs contain Quality of Service properties that must be maintained by a provider, and as agreed between a provider and a user/client. These are generally defined as a set of Service Level Objectives (SLOs). These properties need to be measurable and must be monitored during the provision of the service that has been agreed in the SLA. The SLA must also contain a set of penalty clauses specifying what happens when service providers fail to deliver the pre-agreed quality. Hence, an SLA may be used by both a user and a provider - from a user perspective, an SLA defines what is required - often defined using non-functional attributes of service provision. From a providers perspective, an SLA may be used to support capacity planning - especially if a provider is making it's capability available to multiple users. An SLA may be used by a client and provider to manage their behaviour over time - for instance, to optimise their long running revenue (cost) or QoS attributes (such as execution time), for instance. The lifecycle of an SLA is outlined, along with various uses of SLAs to support infrastructure management. A discussion about WS-Agreement - the emerging standard for specifying SLAs - is also provided.

Service Mediation and Negotiation Bootstrapping as First Achievements Towards Self-adaptable Cloud Services

NASA Astrophysics Data System (ADS)

Brandic, Ivona; Music, Dejan; Dustdar, Schahram

Nowadays, novel computing paradigms as for example Cloud Computing are gaining more and more on importance. In case of Cloud Computing users pay for the usage of the computing power provided as a service. Beforehand they can negotiate specific functional and non-functional requirements relevant for the application execution. However, providing computing power as a service bears different research challenges. On one hand dynamic, versatile, and adaptable services are required, which can cope with system failures and environmental changes. On the other hand, human interaction with the system should be minimized. In this chapter we present the first results in establishing adaptable, versatile, and dynamic services considering negotiation bootstrapping and service mediation achieved in context of the Foundations of Self-Governing ICT Infrastructures (FoSII) project. We discuss novel meta-negotiation and SLA mapping solutions for Cloud services bridging the gap between current QoS models and Cloud middleware and representing important prerequisites for the establishment of autonomic Cloud services.

Analysis of Student Satisfaction Toward Quality of Service Facility

NASA Astrophysics Data System (ADS)

Napitupulu, D.; Rahim, R.; Abdullah, D.; Setiawan, MI; Abdillah, LA; Ahmar, AS; Simarmata, J.; Hidayat, R.; Nurdiyanto, H.; Pranolo, A.

2018-01-01

The development of higher education is very rapid rise to the tight competition both public universities and private colleges. XYZ University realized to win the competition, required continuous quality improvement, including the quality of existing service facilities. Amenities quality services is believed to support the success of the learning activities and improve user satisfaction. This study aims to determine the extent to which the quality of the services effect on user satisfaction. The research method used is survey-based questionnaire that measure perception and expectation. The results showed a gap between perception and expectations of the respondents have a negative value for each item. This means XYZ service facility at the university is not currently meet the expectations of society members. Three service facility that has the lowest index is based on the perception of respondents is a laboratory (2.56), computer and multimedia (2.63) as well as wifi network (2.99). The magnitude of the correlation between satisfaction with the quality of service facilities is 0.725 which means a strong and positive relationship. The influence of the quality of service facilities to the satisfaction of the students is 0.525 meaning that the variable quality of the services facility can explain 52.5% of the variable satisfaction. The study provided recommendations for improvements to enhance the quality of services facility at the XYZ university facilities.

CORSET: Service-Oriented Resource Management System in Linux

NASA Astrophysics Data System (ADS)

Kang, Dong-Jae; Kim, Chei-Yol; Jung, Sung-In

Generally, system resources are not enough for many running services and applications in a system. And services are more important than single process in real world and they have different priority or importance. So each service should be treated with discrimination in aspect of system resources. But administrator can't guarantee the specific service has proper resources in unsettled workload situation because many processes are in race condition. So, we suppose the service-oriented resource management subsystem to resolve upper problems. It guarantees the performance or QoS of the specific service in changeable workload situation by satisfying the minimum resource requirement for the service.

Applying Reflective Middleware Techniques to Optimize a QoS-enabled CORBA Component Model Implementation

NASA Technical Reports Server (NTRS)

Wang, Nanbor; Parameswaran, Kirthika; Kircher, Michael; Schmidt, Douglas

2003-01-01

Although existing CORBA specifications, such as Real-time CORBA and CORBA Messaging, address many end-to-end quality-of service (QoS) properties, they do not define strategies for configuring these properties into applications flexibly, transparently, and adaptively. Therefore, application developers must make these configuration decisions manually and explicitly, which is tedious, error-prone, and open sub-optimal. Although the recently adopted CORBA Component Model (CCM) does define a standard configuration framework for packaging and deploying software components, conventional CCM implementations focus on functionality rather than adaptive quality-of-service, which makes them unsuitable for next-generation applications with demanding QoS requirements. This paper presents three contributions to the study of middleware for QoS-enabled component-based applications. It outlines rejective middleware techniques designed to adaptively (1) select optimal communication mechanisms, (2) manage QoS properties of CORBA components in their contain- ers, and (3) (re)con$gure selected component executors dynamically. Based on our ongoing research on CORBA and the CCM, we believe the application of rejective techniques to component middleware will provide a dynamically adaptive and (re)configurable framework for COTS software that is well-suited for the QoS demands of next-generation applications.

Applying Reflective Middleware Techniques to Optimize a QoS-enabled CORBA Component Model Implementation

NASA Technical Reports Server (NTRS)

Wang, Nanbor; Kircher, Michael; Schmidt, Douglas C.

2000-01-01

Although existing CORBA specifications, such as Real-time CORBA and CORBA Messaging, address many end-to-end quality-of-service (QoS) properties, they do not define strategies for configuring these properties into applications flexibly, transparently, and adaptively. Therefore, application developers must make these configuration decisions manually and explicitly, which is tedious, error-prone, and often sub-optimal. Although the recently adopted CORBA Component Model (CCM) does define a standard configuration frame-work for packaging and deploying software components, conventional CCM implementations focus on functionality rather than adaptive quality-of service, which makes them unsuitable for next-generation applications with demanding QoS requirements. This paper presents three contributions to the study of middleware for QoS-enabled component-based applications. It outlines reflective middleware techniques designed to adaptively: (1) select optimal communication mechanisms, (2) man- age QoS properties of CORBA components in their containers, and (3) (re)configure selected component executors dynamically. Based on our ongoing research on CORBA and the CCM, we believe the application of reflective techniques to component middleware will provide a dynamically adaptive and (re)configurable framework for COTS software that is well-suited for the QoS demands of next-generation applications.

Asynchronous Transfer Mode Quality-of-Service Testing

NASA Technical Reports Server (NTRS)

Ivancic, William D.

1998-01-01

In support of satellite-ATM interoperability, researchers at the NASA Lewis Research Center performed asynchronous transfer mode (ATM) quality-of-service experiments using MPEG-2 (ATM application layer 5, AAL5) over ATM over an emulated satellite link. The purpose of these experiments was to determine the free-space link quality necessary to use the ATM protocol to transmit high-quality multimedia information. The experimental results have been submitted to various International Telecommunications Union (ITU) study groups in order to improve and modify current standards and recommendations for the telecommunications industry. Quality-of-service parameters for Class I, stringent class requirements for ITU-T I.356 are currently being debated. The experimental results presented will help to establish these quality-of-service thresholds. This material will also be useful in the development of the ITU-R WP-4B's Draft Preliminary New Recommendation on the Transmission of Asynchronous Transfer Mode Traffic via Satellite (Rec. S.atm).

42 CFR 475.103 - Requirements for performing quality improvement initiatives.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 4 2014-10-01 2014-10-01 false Requirements for performing quality improvement... HEALTH AND HUMAN SERVICES (CONTINUED) QUALITY IMPROVEMENT ORGANIZATIONS QUALITY IMPROVEMENT ORGANIZATIONS Quality Improvement Organizations § 475.103 Requirements for performing quality improvement initiatives...

77 FR 67366 - Federal Acquisition Regulation; Information Collection; Quality Assurance Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

..., acceptance, warranty, and other measures associated with quality requirements. Standard clauses related to...; Information Collection; Quality Assurance Requirements AGENCY: Department of Defense (DOD), General Services... requirement concerning quality assurance requirements. Public comments are particularly invited on: Whether...

Support of NASA quality requirements by defense contract administration services regions

NASA Technical Reports Server (NTRS)

Farrar, Hiram D.

1966-01-01

Defense Contract Administration Services Regions (DCASR) quality assurance personnel performing under NASA Letters of Delegation must work closely with the assigned technical representative of the NASA centers. It is realized that technical personnel from the NASA Centers cannot make on-site visits as frequently as they would like to. However, DCASR quality assurance personnel would know the assigned NASA technical representative and should contact him when problems arise. The technical representative is the expert on the hardware and should be consulted on any problem area. It is important that the DCASR quality assurance personnel recommend to the delegating NASA Center any new or improved methods of which they may be aware which would assist in achieving the desired quality and reliability in NASA hardware. NASA expects assignment of competent personnel in the Quality Assurance functional area and is not only buying the individual's technical skill, but also his experience. Suggestions by field personnel can many times up-grade the quality or the hardware.

Enhanced Handoff Scheme for Downlink-Uplink Asymmetric Channels in Cellular Systems

PubMed Central

2013-01-01

In the latest cellular networks, data services like SNS and UCC can create asymmetric packet generation rates over the downlink and uplink channels. This asymmetry can lead to a downlink-uplink asymmetric channel condition being experienced by cell edge users. This paper proposes a handoff scheme to cope effectively with downlink-uplink asymmetric channels. The proposed handoff scheme exploits the uplink channel quality as well as the downlink channel quality to determine the appropriate timing and direction of handoff. We first introduce downlink and uplink channel models that consider the intercell interference, to verify the downlink-uplink channel asymmetry. Based on these results, we propose an enhanced handoff scheme that exploits both the uplink and downlink channel qualities to reduce the handoff-call dropping probability and the service interruption time. The simulation results show that the proposed handoff scheme reduces the handoff-call dropping probability about 30% and increases the satisfaction of the service interruption time requirement about 7% under high-offered load, compared to conventional mobile-assisted handoff. Especially, the proposed handoff scheme is more efficient when the uplink QoS requirement is much stricter than the downlink QoS requirement or uplink channel quality is worse than downlink channel quality. PMID:24501576

Hierarchy Bayesian model based services awareness of high-speed optical access networks

NASA Astrophysics Data System (ADS)

Bai, Hui-feng

2018-03-01

As the speed of optical access networks soars with ever increasing multiple services, the service-supporting ability of optical access networks suffers greatly from the shortage of service awareness. Aiming to solve this problem, a hierarchy Bayesian model based services awareness mechanism is proposed for high-speed optical access networks. This approach builds a so-called hierarchy Bayesian model, according to the structure of typical optical access networks. Moreover, the proposed scheme is able to conduct simple services awareness operation in each optical network unit (ONU) and to perform complex services awareness from the whole view of system in optical line terminal (OLT). Simulation results show that the proposed scheme is able to achieve better quality of services (QoS), in terms of packet loss rate and time delay.

Cross-layer protocols optimized for real-time multimedia services in energy-constrained mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Hortos, William S.

2003-07-01

Mobile ad hoc networking (MANET) supports self-organizing, mobile infrastructures and enables an autonomous network of mobile nodes that can operate without a wired backbone. Ad hoc networks are characterized by multihop, wireless connectivity via packet radios and by the need for efficient dynamic protocols. All routers are mobile and can establish connectivity with other nodes only when they are within transmission range. Importantly, ad hoc wireless nodes are resource-constrained, having limited processing, memory, and battery capacity. Delivery of high quality-ofservice (QoS), real-time multimedia services from Internet-based applications over a MANET is a challenge not yet achieved by proposed Internet Engineering Task Force (IETF) ad hoc network protocols in terms of standard performance metrics such as end-to-end throughput, packet error rate, and delay. In the distributed operations of route discovery and maintenance, strong interaction occurs across MANET protocol layers, in particular, the physical, media access control (MAC), network, and application layers. The QoS requirements are specified for the service classes by the application layer. The cross-layer design must also satisfy the battery-limited energy constraints, by minimizing the distributed power consumption at the nodes and of selected routes. Interactions across the layers are modeled in terms of the set of concatenated design parameters including associated energy costs. Functional dependencies of the QoS metrics are described in terms of the concatenated control parameters. New cross-layer designs are sought that optimize layer interdependencies to achieve the "best" QoS available in an energy-constrained, time-varying network. The protocol design, based on a reactive MANET protocol, adapts the provisioned QoS to dynamic network conditions and residual energy capacities. The cross-layer optimization is based on stochastic dynamic programming conditions derived from time-dependent models of

A fuzzy call admission control scheme in wireless networks

NASA Astrophysics Data System (ADS)

Ma, Yufeng; Gong, Shenguang; Hu, Xiulin; Zhang, Yunyu

2007-11-01

Scarcity of the spectrum resource and mobility of users make quality of service (QoS) provision a critical issue in wireless networks. This paper presents a fuzzy call admission control scheme to meet the requirement of the QoS. A performance measure is formed as a weighted linear function of new call and handoff call blocking probabilities. Simulation compares the proposed fuzzy scheme with an adaptive channel reservation scheme. Simulation results show that fuzzy scheme has a better robust performance in terms of average blocking criterion.

A new three-dimensional manufacturing service composition method under various structures using improved Flower Pollination Algorithm

NASA Astrophysics Data System (ADS)

Zhang, Wenyu; Yang, Yushu; Zhang, Shuai; Yu, Dejian; Chen, Yong

2018-05-01

With the growing complexity of customer requirements and the increasing scale of manufacturing services, how to select and combine the single services to meet the complex demand of the customer has become a growing concern. This paper presents a new manufacturing service composition method to solve the multi-objective optimization problem based on quality of service (QoS). The proposed model not only presents different methods for calculating the transportation time and transportation cost under various structures but also solves the three-dimensional composition optimization problem, including service aggregation, service selection, and service scheduling simultaneously. Further, an improved Flower Pollination Algorithm (IFPA) is proposed to solve the three-dimensional composition optimization problem using a matrix-based representation scheme. The mutation operator and crossover operator of the Differential Evolution (DE) algorithm are also used to extend the basic Flower Pollination Algorithm (FPA) to improve its performance. Compared to Genetic Algorithm, DE, and basic FPA, the experimental results confirm that the proposed method demonstrates superior performance than other meta heuristic algorithms and can obtain better manufacturing service composition solutions.

The Students' Viewpoint on Quality of Educational Services in Iran.

PubMed

Siamian, Hasan; Rostami, Farideh; Ghara, Aliasghar Nadi; Abedi, Ghassem

2017-03-01

Recently, focusing on higher education quality has got increasingly critical. The novel managerial attitudes have defined the customer-demanded quality. Based on this, recognizing the receivers' perception of the quality of the services offered and evaluating the quality of the service is considered of the basic measures taken in order to develop quality promotion programs. Therefore, this is a qualitative research conducted for students' viewpoint on quality of educational services. This qualitative study has been performed by the phenomenological method. The samples have been selected based on goal-oriented approach. In this qualitative research, the required data have been collected in two phases (90 individual interviews and 30 focus group discussions) at Mazandaran University of Medical Sciences during which the participants have conveyed their experiences and expectations encountering the educational quality topic. All the interviews have been recorded and implemented. The interviews analysis has been carried out simultaneously with the implementation and using theme analysis by Smith method. According to the findings regarding the definition of quality, the students have emphasized two important aspects including "educational services standards by the teacher "and "the students' satisfaction". Thus the final education quality resulted from the students' experiences and perception is this way: "Presenting the students educational services in class and out of class compatible with the educational services standards so that it results in the students' satisfaction". When a person views her/him-self rightful as a customer, whatever seems necessary to them appears like a requirement. Then regarding paying attention and reflecting on the customers' perceived needs, it is possible to determine their expectations limit to some extent. Therefore, designing educational quality standards in order to evaluate the teachers' function without taking the stakeholders

QoS Adaptation in Multimedia Multicast Conference Applications for E-Learning Services

ERIC Educational Resources Information Center

Deusdado, Sérgio; Carvalho, Paulo

2006-01-01

The evolution of the World Wide Web service has incorporated new distributed multimedia conference applications, powering a new generation of e-learning development and allowing improved interactivity and prohuman relations. Groupware applications are increasingly representative in the Internet home applications market, however, the Quality of…

5 CFR 531.504 - Level of performance required for quality step increase.

Code of Federal Regulations, 2010 CFR

2010-01-01

... step increase. 531.504 Section 531.504 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER THE GENERAL SCHEDULE Quality Step Increases § 531.504 Level of performance required for quality step increase. A quality step increase shall not be required but may be granted only...

Evaluation of service quality of hospital outpatient department services.

PubMed

Chakravarty, Abhijit

2011-07-01

It has become essential for hospital managers to understand and measure consumer perspectives and service quality gaps, so that any perceived gap in delivery of service is identified and suitably addressed. A study was conducted at a peripheral service hospital to ascertain any service gap between consumer expectations and perceptions in respect of the hospital outpatient department (OPD) services. A cross-sectional study was conducted using SERVQUAL as the survey instrument, the instrument being validated for use in the hospital environment. Consumer ratings across 22 items of the survey instrument were collected in paired expectation and perception scores and then service quality gaps were identified and statistically analysed. Service quality gaps were identified to exist across all the five dimensions of the survey instrument, with statistically significant gaps across the dimensions of 'tangibles' and 'responsiveness.' The quality gaps were further validated by a total unweighted SERVQUAL score of (-) 1.63. The study concludes that significant service quality gaps existed in the delivery of the hospital OPD services, which need to be addressed by focused improvement efforts by the hospital management.

QoS Negotiation in Real-Time Systems and its Application to Automated Flight Control

DTIC Science & Technology

2000-11-01

QoS Negotiation in Real - Time Systems and Its Application to Automated Flight Control Tarek F. Abdelzaher, Member, IEEE, Ella M. Atkins, Member, IEEE...been committed to those that arrived earlier. In hard- real - time systems , a static analysis may be performed to guarantee a priori that all requests be...DATE 2000 2. REPORT TYPE 3. DATES COVERED 00-00-2000 to 00-00-2000 4. TITLE AND SUBTITLE QoS Negotiation in Real - Time Systems and its

COMSATCOM service technical baseline strategy development approach using PPBW concept

NASA Astrophysics Data System (ADS)

Nguyen, Tien M.; Guillen, Andy T.

2016-05-01

This paper presents an innovative approach to develop a Commercial Satellite Communications (COMSATCOM) service Technical Baseline (TB) and associated Program Baseline (PB) strategy using Portable Pool Bandwidth (PPBW) concept. The concept involves trading of the purchased commercial transponders' Bandwidths (BWs) with existing commercial satellites' bandwidths participated in a "designated pool bandwidth"3 according to agreed terms and conditions. Space Missile Systems Center (SMC) has been implementing the Better Buying Power (BBP 3.0) directive4 and recommending the System Program Offices (SPO) to own the Program and Technical Baseline (PTB) [1, 2] for the development of flexible acquisition strategy and achieving affordability and increased in competition. This paper defines and describes the critical PTB parameters and associated requirements that are important to the government SPO for "owning" an affordable COMSATCOM services contract using PPBW trading concept. The paper describes a step-by-step approach to optimally perform the PPBW trading to meet DoD and its stakeholders (i) affordability requirement, and (ii) fixed and variable bandwidth requirements by optimizing communications performance, cost and PPBW accessibility in terms of Quality of Services (QoS), Bandwidth Sharing Ratio (BSR), Committed Information Rate (CIR), Burstable Information Rate (BIR), Transponder equivalent bandwidth (TPE) and transponder Net Presence Value (NPV). The affordable optimal solution that meets variable bandwidth requirements will consider the operating and trading terms and conditions described in the Fair Access Policy (FAP).

Research on Holographic Evaluation of Service Quality in Power Data Network

NASA Astrophysics Data System (ADS)

Wei, Chen; Jing, Tao; Ji, Yutong

2018-01-01

With the rapid development of power data network, the continuous development of the Power data application service system, more and more service systems are being put into operation. Following this, the higher requirements for network quality and service quality are raised, in the actual process for the network operation and maintenance. This paper describes the electricity network and data network services status. A holographic assessment model was presented to achieve a comprehensive intelligence assessment on the power data network and quality of service in the operation and maintenance on the power data network. This evaluation method avoids the problems caused by traditional means which performs a single assessment of network performance quality. This intelligent Evaluation method can improve the efficiency of network operation and maintenance guarantee the quality of real-time service in the power data network..

Real-time services in IP network architectures

NASA Astrophysics Data System (ADS)

Gilardi, Antonella

1996-12-01

The worldwide internet system seems to be the success key for the provision of real time multimedia services to both residential and business users and someone says that in such a way broadband networks will have a reason to exist. This new class of applications that use multiple media (voice, video and data) impose constraints to the global network nowadays consisting of subnets with various data links. The attention will be focused on the interconnection of IP non ATM and ATM networks. IETF and ATM forum are currently involved in the developing specifications suited to adapt the connectionless IP protocol to the connection oriented ATM protocol. First of all the link between the ATM and the IP service model has to be set in order to match the QoS and traffic requirements defined in the relative environment. A further significant topic is represented by the mapping of IP resource reservation model onto the ATM signalling and in the end it is necessary to define how the routing works when there are QoS parameters associated. This paper, considering only unicast applications, will examine the above issues taking as a starting point the situation where an host launches as call set up request with the relevant QoS and traffic descriptor and at some point a router at the edge of the ATM network has to decide how forwarding and request in order to establish an end to end link with the right capabilities. The aim is to compare the proposals emerging from different standard bodies to point out convergency or incompatibility.

Dynamic Reconfiguration of a RGBD Sensor Based on QoS and QoC Requirements in Distributed Systems.

PubMed

Munera, Eduardo; Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Noguera, Juan Fco Blanes

2015-07-24

The inclusion of embedded sensors into a networked system provides useful information for many applications. A Distributed Control System (DCS) is one of the clearest examples where processing and communications are constrained by the client's requirements and the capacity of the system. An embedded sensor with advanced processing and communications capabilities supplies high level information, abstracting from the data acquisition process and objects recognition mechanisms. The implementation of an embedded sensor/actuator as a Smart Resource permits clients to access sensor information through distributed network services. Smart resources can offer sensor services as well as computing, communications and peripheral access by implementing a self-aware based adaptation mechanism which adapts the execution profile to the context. On the other hand, information integrity must be ensured when computing processes are dynamically adapted. Therefore, the processing must be adapted to perform tasks in a certain lapse of time but always ensuring a minimum process quality. In the same way, communications must try to reduce the data traffic without excluding relevant information. The main objective of the paper is to present a dynamic configuration mechanism to adapt the sensor processing and communication to the client's requirements in the DCS. This paper describes an implementation of a smart resource based on a Red, Green, Blue, and Depth (RGBD) sensor in order to test the dynamic configuration mechanism presented.

The Students’ Viewpoint on Quality of Educational Services in Iran

PubMed Central

Siamian, Hasan; Rostami, Farideh; Ghara, Aliasghar Nadi; Abedi, Ghassem

2017-01-01

Background: Recently, focusing on higher education quality has got increasingly critical. The novel managerial attitudes have defined the customer-demanded quality. Based on this, recognizing the receivers’ perception of the quality of the services offered and evaluating the quality of the service is considered of the basic measures taken in order to develop quality promotion programs. Therefore, this is a qualitative research conducted for students’ viewpoint on quality of educational services. Material and Methods: This qualitative study has been performed by the phenomenological method. The samples have been selected based on goal-oriented approach. In this qualitative research, the required data have been collected in two phases (90 individual interviews and 30 focus group discussions) at Mazandaran University of Medical Sciences during which the participants have conveyed their experiences and expectations encountering the educational quality topic. All the interviews have been recorded and implemented. The interviews analysis has been carried out simultaneously with the implementation and using theme analysis by Smith method. Results: According to the findings regarding the definition of quality, the students have emphasized two important aspects including “educational services standards by the teacher “and “the students’ satisfaction”. Thus the final education quality resulted from the students’ experiences and perception is this way: “Presenting the students educational services in class and out of class compatible with the educational services standards so that it results in the students’ satisfaction”. When a person views her/him-self rightful as a customer, whatever seems necessary to them appears like a requirement. Then regarding paying attention and reflecting on the customers’ perceived needs, it is possible to determine their expectations limit to some extent. Conclusion: Therefore, designing educational quality standards in

Research on quality metrics of wireless adaptive video streaming

NASA Astrophysics Data System (ADS)

Li, Xuefei

2018-04-01

With the development of wireless networks and intelligent terminals, video traffic has increased dramatically. Adaptive video streaming has become one of the most promising video transmission technologies. For this type of service, a good QoS (Quality of Service) of wireless network does not always guarantee that all customers have good experience. Thus, new quality metrics have been widely studies recently. Taking this into account, the objective of this paper is to investigate the quality metrics of wireless adaptive video streaming. In this paper, a wireless video streaming simulation platform with DASH mechanism and multi-rate video generator is established. Based on this platform, PSNR model, SSIM model and Quality Level model are implemented. Quality Level Model considers the QoE (Quality of Experience) factors such as image quality, stalling and switching frequency while PSNR Model and SSIM Model mainly consider the quality of the video. To evaluate the performance of these QoE models, three performance metrics (SROCC, PLCC and RMSE) which are used to make a comparison of subjective and predicted MOS (Mean Opinion Score) are calculated. From these performance metrics, the monotonicity, linearity and accuracy of these quality metrics can be observed.

Evaluation of first-year Florida MPO transit capacity and quality of service reports

DOT National Transportation Integrated Search

2001-12-01

As an application of the transit quality of service framework presented in the First Edition of the Transit Capacity and Quality of Service Manual (TCQSM), the Florida Department of Transportation (FDOT) required all MPOs in the state where fixed-rou...

Resource Management in QoS-Aware Wireless Cellular Networks

ERIC Educational Resources Information Center

Zhang, Zhi

2011-01-01

Emerging broadband wireless networks that support high speed packet data with heterogeneous quality of service (QoS) requirements demand more flexible and efficient use of the scarce spectral resource. Opportunistic scheduling exploits the time-varying, location-dependent channel conditions to achieve multiuser diversity. In this work, we study…

Factor selection for service quality evaluation: a hospital case study.

PubMed

Ameryoun, Ahmad; Najafi, Seyedvahid; Nejati-Zarnaqi, Bayram; Khalilifar, Seyed Omid; Ajam, Mahdi; Ansarimoghadam, Ahmad

2017-02-13

Purpose The purpose of this paper is to develop a systematic approach to predict service quality dimension's influence on service quality using a novel analysis based on data envelopment and SERVQUAL. Design/methodology/approach To assess hospital service quality in Tehran, expectation and perception of those who received the services were evaluated using SERVQUAL. The hospital service quality dimensions were found by exploratory factor analysis (EFA). To compare customer expectation and perception, perceived service quality index (PSQI) was measured using a new method based on common weights. A novel sensitivity approach was used to test the service quality factor's impact on the PSQI. Findings A new service quality dimension named "trust in services" was found using EFA, which is not an original SERVQUAL factor. The approach was applied to assess the hospital's service quality. Since the PSQI value was 0.76 it showed that improvements are needed to meet customer expectations. The results showed the factor order that affect PSQI. "Trust in services" has the strongest influence on PSQI followed by "tangibles," "assurance," "empathy," and "responsiveness," respectively. Practical implications This work gives managers insight into service quality by following a systematic method; i.e., measuring perceived service quality from the customer viewpoint and service factors' impact on customer perception. Originality/value The procedure helps managers to select the required service quality dimensions which need improvement and predict their effects on customer perception.

An overview of service quality of continuous positive airway pressure services in Australian pharmacies.

PubMed

Hanes, Carissa A; Wong, Keith K H; Saini, Bandana

2014-01-01

Little is known about CPAP services offered in the Australian primary care pharmacy setting, despite the potential influence of service quality on patient adherence. The objective of this study was to provide an overview on a nationwide scale of the range and quality of CPAP and sleep apnoea-related services in Australian pharmacies. A paper-based questionnaire was developed and mailed to all pharmacies in Australia that currently provide CPAP services (as identified by manufacturer's distributor lists or Internet search). A point system was devised to score participants on the quality of their CPAP service. Pharmacies were rated against a list of 23 criteria that were determined by consensus, with one point allocated for each criterion met, allowing for a maximum score of 23. The study response rate was 55% (110/199), and representation was obtained from all eight Australian states and territories. The mean number of criteria met (total score) for pharmacies was 15.7 ± 3.4 (15.7/23 = 68.3%; score range 2-22). Variability was evident in the range of services offered. Eighty-seven per cent of respondents believed that pharmacies supplying CPAP should adhere to a formalized set of professional guidelines. The accessibility of pharmacies may make them a valuable venue for CPAP service provision. However, models of care to guide practice and standardize the variability in services are required. Implementation of such models could improve patient access to quality treatment in the primary care setting. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

Framework for analysis of guaranteed QOS systems

NASA Astrophysics Data System (ADS)

Chaudhry, Shailender; Choudhary, Alok

1997-01-01

Multimedia data is isochronous in nature and entails managing and delivering high volumes of data. Multiprocessors with their large processing power, vast memory, and fast interconnects, are an ideal candidate for the implementation of multimedia applications. Initially, multiprocessors were designed to execute scientific programs and thus their architecture was optimized to provide low message latency and efficiently support regular communication patterns. Hence, they have a regular network topology and most use wormhole routing. The design offers the benefits of a simple router, small buffer size, and network latency that is almost independent of path length. Among the various multimedia applications, video on demand (VOD) server is well-suited for implementation using parallel multiprocessors. Logical models for VOD servers are presently mapped onto multiprocessors. Our paper provides a framework for calculating bounds on utilization of system resources with which QoS parameters for each isochronous stream can be guaranteed. Effects of the architecture of multiprocessors, and efficiency of various local models and mapping on particular architectures can be investigated within our framework. Our framework is based on rigorous proofs and provides tight bounds. The results obtained may be used as the basis for admission control tests. To illustrate the versatility of our framework, we provide bounds on utilization for various logical models applied to mesh connected architectures for a video on demand server. Our results show that worm hole routing can lead to packets waiting for transmission of other packets that apparently share no common resources. This situation is analogous to head-of-the-line blocking. We find that the provision of multiple VCs per link and multiple flit buffers improves utilization (even under guaranteed QoS parameters). This analogous to parallel iterative matching.

Factors Affecting Medical Service Quality.

PubMed

Mosadeghrad, Ali Mohammad

2014-02-01

A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians. Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran. Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment. Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality.

A roadmap for improving healthcare service quality.

PubMed

Kennedy, Denise M; Caselli, Richard J; Berry, Leonard L

2011-01-01

A data-driven, comprehensive model for improving service and creating long-term value was developed and implemented at Mayo Clinic Arizona (MCA). Healthcare organizations can use this model to prepare for value-based purchasing, a payment system in which quality and patient experience measures will influence reimbursement. Surviving and thriving in such a system will require a comprehensive approach to sustaining excellent service performance from physicians and allied health staff (e.g., nurses, technicians, nonclinical staff). The seven prongs in MCA's service quality improvement model are (1) multiple data sources to drive improvement, (2) accountability for service quality, (3) service consultation and improvement tools, (4) service values and behaviors, (5) education and training, (6) ongoing monitoring and control, and (7) recognition and reward. The model was fully implemented and tested in five departments in which patient perception of provider-specific service attributes and/or overall quality of care were below the 90th percentile for patient satisfaction in the vendor's database. Extent of the implementation was at the discretion of department leadership. Perception data rating various service attributes were collected from randomly selected patients and monitored over a 24-month period. The largest increases in patient perception of excellence over the pilot period were realized when all seven prongs of the model were implemented as a comprehensive improvement approach. The results of this pilot may help other healthcare organizations prepare for value-based purchasing.

On using multiple routing metrics with destination sequenced distance vector protocol for MultiHop wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Mehic, M.; Fazio, P.; Voznak, M.; Partila, P.; Komosny, D.; Tovarek, J.; Chmelikova, Z.

2016-05-01

A mobile ad hoc network is a collection of mobile nodes which communicate without a fixed backbone or centralized infrastructure. Due to the frequent mobility of nodes, routes connecting two distant nodes may change. Therefore, it is not possible to establish a priori fixed paths for message delivery through the network. Because of its importance, routing is the most studied problem in mobile ad hoc networks. In addition, if the Quality of Service (QoS) is demanded, one must guarantee the QoS not only over a single hop but over an entire wireless multi-hop path which may not be a trivial task. In turns, this requires the propagation of QoS information within the network. The key to the support of QoS reporting is QoS routing, which provides path QoS information at each source. To support QoS for real-time traffic one needs to know not only minimum delay on the path to the destination but also the bandwidth available on it. Therefore, throughput, end-to-end delay, and routing overhead are traditional performance metrics used to evaluate the performance of routing protocol. To obtain additional information about the link, most of quality-link metrics are based on calculation of the lost probabilities of links by broadcasting probe packets. In this paper, we address the problem of including multiple routing metrics in existing routing packets that are broadcasted through the network. We evaluate the efficiency of such approach with modified version of DSDV routing protocols in ns-3 simulator.

Quality of Services and Quality of Life from Service Providers' Perspectives: Analysis with Focus Groups

ERIC Educational Resources Information Center

Jenaro, C.; Vega, V.; Flores, N.; Cruz, M.

2013-01-01

Background: Concepts such as support, quality of life and quality of services are customary in services for people with intellectual disabilities. The identification of the different ways of conceiving, prioritising and implementing these concepts by service providers can help to drive changes to achieve better personal outcomes for this…

Quality of sleep and psychosocial factors for patients undergoing peritoneal dialysis.

PubMed

Yang, Ju-Yeh; Huang, Jenq-Wen; Peng, Yu-Sen; Chiang, Shou-Shang; Yang, Chwei-Shiun; Yang, Chin-Ching; Chen, Huey-Wen; Wu, Ming-Shiou; Wu, Kwan-Dun; Tsai, Tun-Jun; Chen, Wan-Yu

2007-01-01

Sleep disorders are common in end-stage renal disease patients. This study examined the relationship between self-reported quality of sleep (QoS) and certain psychosocial domains for patients on peritoneal dialysis (PD). The study subjects included 190 PD patients from 7 urban dialysis clinics in Northern Taiwan, from whom we obtained biochemical parameters and demographic data. QoS, quality of life (QoL), religious/spiritual activity, and depression were assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire, Medical Outcomes Study Short Form (SF-36) for QoL, the Royal Free Questionnaire, and the Beck Depression Inventory, respectively. The average PSQI score was 9.1 +/- 4.1 and, in total, 85.8% of all patients were poor sleepers (global PSQI > or =5). There was no difference in age, gender, and mode or duration of PD between good and poor sleepers. Biochemical data did not differ between the two groups. Widowed patients experienced significantly poorer QoS than patients with other marital status (PSQI scores: 12.3 +/- 4.9 vs 8.88 +/- 4.0, p = 0.006). The percentage of patients that held a bachelor's degree or above was significantly higher in good sleepers (55.6% vs 29.4%, p = 0.008). The PSQI value correlated negatively with the QoL scale in both physical (r = -0.295, p < 0.001) and mental domains (r = -0.410, p < 0.001), and correlated positively with the depression scale (r = 0.351, p < 0.001). There appeared to be no association between QoS and spiritual/religious activity (r = -0.097, p = 0.223). Psychosocial factors including depression, patients' perceptions regarding QoL, marital status, and educational background correlated significantly to the subjective QoS for PD patients. When dealing with sleep disorders in PD patients, physicians should pay considerable attention to their psychosocial backgrounds.

42 CFR 412.44 - Medical review requirements: Admissions and quality review.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 2 2014-10-01 2014-10-01 false Medical review requirements: Admissions and quality review. 412.44 Section 412.44 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF... Capital-Related Costs § 412.44 Medical review requirements: Admissions and quality review. Beginning on...

Service quality in health care setting.

PubMed

Rashid, Wan Edura Wan; Jusoff, Hj Kamaruzaman

2009-01-01

This paper attempts to explore the concept of service quality in a health care setting. This paper probes the definition of service quality from technical and functional aspects for a better understanding on how consumers evaluate the quality of health care. It adopts the conceptual model of service quality frequently used by the most researchers in the health care sector. The paper also discusses several service quality dimensions and service quality problems in order to provide a more holistic conception of hospital service quality. The paper finds that service quality in health care is very complex as compared to other services because this sector highly involves risk. The paper adds a new perspective towards understanding how the concept of service quality is adopted in a health care setting.

Call Admission Control on Single Node Networks under Output Rate-Controlled Generalized Processor Sharing (ORC-GPS) Scheduler

NASA Astrophysics Data System (ADS)

Hanada, Masaki; Nakazato, Hidenori; Watanabe, Hitoshi

Multimedia applications such as music or video streaming, video teleconferencing and IP telephony are flourishing in packet-switched networks. Applications that generate such real-time data can have very diverse quality-of-service (QoS) requirements. In order to guarantee diverse QoS requirements, the combined use of a packet scheduling algorithm based on Generalized Processor Sharing (GPS) and leaky bucket traffic regulator is the most successful QoS mechanism. GPS can provide a minimum guaranteed service rate for each session and tight delay bounds for leaky bucket constrained sessions. However, the delay bounds for leaky bucket constrained sessions under GPS are unnecessarily large because each session is served according to its associated constant weight until the session buffer is empty. In order to solve this problem, a scheduling policy called Output Rate-Controlled Generalized Processor Sharing (ORC-GPS) was proposed in [17]. ORC-GPS is a rate-based scheduling like GPS, and controls the service rate in order to lower the delay bounds for leaky bucket constrained sessions. In this paper, we propose a call admission control (CAC) algorithm for ORC-GPS, for leaky-bucket constrained sessions with deterministic delay requirements. This CAC algorithm for ORC-GPS determines the optimal values of parameters of ORC-GPS from the deterministic delay requirements of the sessions. In numerical experiments, we compare the CAC algorithm for ORC-GPS with one for GPS in terms of schedulable region and computational complexity.

A quality function deployment framework for the service quality of health information websites.

PubMed

Chang, Hyejung; Kim, Dohoon

2010-03-01

This research was conducted to identify both the users' service requirements on health information websites (HIWs) and the key functional elements for running HIWs. With the quality function deployment framework, the derived service attributes (SAs) are mapped into the suppliers' functional characteristics (FCs) to derive the most critical FCs for the users' satisfaction. Using the survey data from 228 respondents, the SAs, FCs and their relationships were analyzed using various multivariate statistical methods such as principal component factor analysis, discriminant analysis, correlation analysis, etc. Simple and compound FC priorities were derived by matrix calculation. Nine factors of SAs and five key features of FCs were identified, and these served as the basis for the house of quality model. Based on the compound FC priorities, the functional elements pertaining to security and privacy, and usage support should receive top priority in the course of enhancing HIWs. The quality function deployment framework can improve the FCs of the HIWs in an effective, structured manner, and it can also be utilized for critical success factors together with their strategic implications for enhancing the service quality of HIWs. Therefore, website managers could efficiently improve website operations by considering this study's results.

Does Person-Centered Care Improve Residents' Satisfaction With Nursing Home Quality?

PubMed

Poey, Judith L; Hermer, Linda; Cornelison, Laci; Kaup, Migette L; Drake, Patrick; Stone, Robyn I; Doll, Gayle

2017-11-01

Person-centered care (PCC) is meant to enhance nursing home residents' quality of life (QOL). Including residents' perspectives is critical to determining whether PCC is meeting residents' needs and desires. This study examines whether PCC practices promote satisfaction with QOL and quality of care and services (QOC and QOS) among nursing home residents. A longitudinal, retrospective cohort study using an in-person survey. Three hundred twenty nursing homes in Kansas enrolled or not enrolled in a pay-for-performance program, Promoting Excellent Alternatives in Kansas (PEAK 2.0), to promote PCC in nursing homes. A total of 6214 nursing home residents in 2013-2014 and 5538 residents in 2014-2015, with a Brief Interview for Mental Status score ≥8, participated in face-to-face interviews. Results were aggregated to the nursing home level. My InnerView developed a Resident Satisfaction Survey for Kansas composed of 32 questions divided into QOL, QOC, QOS, and global satisfaction subdomains. After controlling for facility characteristics, satisfaction with overall QOL and QOC was higher in homes that had fully implemented PCC. Although some individual measures in the QOS domain (eg, food) showed greater satisfaction at earlier levels of implementation, high satisfaction was observed primarily in homes that had fully implemented PCC. These findings provide evidence for the effectiveness of PCC implementation on nursing home resident satisfaction. The PEAK 2.0 program may provide replicable methods for nursing homes and states to implement PCC systematically. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Motivating Customer Service Employees to Deliver Service Quality

DTIC Science & Technology

1999-12-01

Motivating Customer Service Employees to Deliver Service Quality A Professional Paper Presented to The Faculty of the Conrad Hilton College of...AGENCY USE ONLY (Leave blank) REPORT DATE ■W-MJl.UU MAJOR REPORT 4. TITLE AND SUBTITLE MOTIVATING CUSTOMER SERVICE EMPLOYEESTO DELIVER SERVICE...DIOR, Oct 94 Motivating Customer Service Employees to Deliver Service Quality A Professional Paper Presented to The Faculty of the Conrad Hilton

[The telemedical service centre as an essential element of the conceptual approach for telemonitoring of cardiac patients : Requirements on the service, quality, and technical realization of telemonitoring].

PubMed

Helms, T M; Müller, A; Perings, C; Köhler, F; Leonhardt, V; Rybak, K; Sack, S; Stockburger, M

2017-09-01

Telemonitoring as part of a treatment strategy supports and facilitates the monitoring, disease management and education of patients with heart failure and cardiac arrhythmias. Therefore, telemonitoring affects quality and success of the therapy. Thus, meeting the needs of the patients and of the involved health care professionals is important for the success of the telemonitoring service. Moreover, a high quality of the service has to be ensured. The following article describes several configuration options for telemonitoring services considering technical as well as quality- and service-related aspects.

Scheduling multimedia services in cloud computing environment

NASA Astrophysics Data System (ADS)

Liu, Yunchang; Li, Chunlin; Luo, Youlong; Shao, Yanling; Zhang, Jing

2018-02-01

Currently, security is a critical factor for multimedia services running in the cloud computing environment. As an effective mechanism, trust can improve security level and mitigate attacks within cloud computing environments. Unfortunately, existing scheduling strategy for multimedia service in the cloud computing environment do not integrate trust mechanism when making scheduling decisions. In this paper, we propose a scheduling scheme for multimedia services in multi clouds. At first, a novel scheduling architecture is presented. Then, We build a trust model including both subjective trust and objective trust to evaluate the trust degree of multimedia service providers. By employing Bayesian theory, the subjective trust degree between multimedia service providers and users is obtained. According to the attributes of QoS, the objective trust degree of multimedia service providers is calculated. Finally, a scheduling algorithm integrating trust of entities is proposed by considering the deadline, cost and trust requirements of multimedia services. The scheduling algorithm heuristically hunts for reasonable resource allocations and satisfies the requirement of trust and meets deadlines for the multimedia services. Detailed simulated experiments demonstrate the effectiveness and feasibility of the proposed trust scheduling scheme.

Influence of Security Mechanisms on the Quality of Service of VoIP

NASA Astrophysics Data System (ADS)

Backs, Peter; Pohlmann, Norbert

While Voice over IP (VoIP) is advancing rapidly in the telecommunications market, the interest to protect the data transmitted by this new service is also rising. However, in contrast to other internet services such as email or HTTP, VoIP is real-time media, and therefore must meet a special requirement referred to as Quality-of-Service to provide a comfortable flow of speech. Speech quality is worsened when transmitted over the network due to delays in transmission or loss of packets. Often, voice quality is at a level that even prevents comprehensive dialog. Therefore, an administrator who is to setup a VoIP infrastructure might consider avoiding additional decreases in voice quality resulting from security mechanisms, and might leave internet telephony unprotected as a result. The inspiration for this paper is to illustrate that security mechanisms have negligible impact on speech quality and should in fact be encouraged.

Technical requirements for bioassay support services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickman, D.P.; Anderson, A.L.

1991-05-01

This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) bioassay program. It includes information and details that can be used as a model in providing technical contents and requirements for bioassay laboratory support, either internally or in solicitations by Geotech to obtain subcontractor laboratory support. It provides a detailed summary and description of the types of bioassay samples to be expected in support of Geotech remedial projects for the US Department of Energy and the bioassay services and analytical requirements necessary to process such samples, including required limits of sensitivity. General responsibilities of the bioassay laboratory are alsomore » addressed, including quality assurance. Peripheral information of importance to the program is included in the appendices of this document. 7 tabs.« less

78 FR 72620 - Federal Acquisition Regulation; Higher-Level Contract Quality Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-03

... DEPARTMENT OF DEFENSE GENERAL SERVICES ADMINISTRATION NATIONAL AERONAUTICS AND SPACE.... IV. Regulatory Flexibility Act The Department of Defense (DoD), the General Services Administration...-AM65 Federal Acquisition Regulation; Higher-Level Contract Quality Requirements AGENCY: Department of...

The structure of service quality perceptions for multiple-encounter services.

PubMed

Andaleeb, Syed Saad; Kara, Ali

2013-01-01

The objective of this study was to examine a complex service environment-hospitals-to suggest how service quality could be reframed and measured for multiple-encounter service situations more effectively. In this cross-sectional study, a sample of 371 patients completed the survey instrument. Service quality measures were guided by the literature but allowed to flow from the respondents at the preliminary stage. Confirmatory factor analysis, along with structural equation modeling, was used to test the hypothesized relationships among key actors' performance metrics (KAPMs). Patient satisfaction is significantly influenced by perceived service quality based on KAPMs. For multiple-encounter services, service quality dimensions and measures ought to be tied to KAPMs. Primary actors-ie, doctors-need knowledge and skills about patient psychology, negotiation, handling difficult patients, and, importantly, "putting the customer first." Sensitivity training on such matters should be provided. The secondary actors are the nurses who have more frequent contact with the patients. Nurses need to be perceived as "patient advocates." Effective advocacy begins with prompt and caring services to build trust. The tertiary actors in their support role also ought to be integrated into becoming vital part of the service provided.

Optical burst switching for the next generation Optical Internet

NASA Astrophysics Data System (ADS)

Yoo, Myungsik

2000-11-01

In recent years, Internet Protocol (IP) over Wavelength Division Multiplexing (WDM) networks for the next generation Internet (or the so-called Optical Internet) have received enormous attention. There are two main drivers for an Optical Internet. One is the explosion of Internet traffic, which seems to keep growing exponentially. The other driver is the rapid advance in the WDM optical networking technology. In this study, key issues in the optical (WDM) layer will be investigated. As a novel switching paradigm for Optical Internet, Optical Burst Switching (OBS) is discussed. By leveraging the attractive properties of optical communications and at the same time, taking into account its limitations, OBS can combine the best of optical circuit-switching and packet/cell switching. The general concept of JET-based OBS protocol is described, including offset time and delayed reservation. In the next generation Optical Internet, one must address how to support Quality of Service (QoS) at the WDM layer since current IP provides only best effort services. The offset-time- based QoS scheme is proposed as a way of supporting QoS at the WDM layer. Unlike existing QoS schemes, offset- time-based QoS scheme does not mandate the use of buffer to differentiate services. For the bufferless WDM switch, the performance of offset- time-based QoS scheme is evaluated in term of blocking probability. In addition, the extra offset time required for class isolation is quantified and the theoretical bounds on blocking probability are analyzed. The offset-time-based scheme is applied to WDM switch with limited fiber delay line (FDL) buffer. We evaluate the effect of having a FDL buffer on the QoS performance of the offset-time-based scheme in terms of the loss probability and queuing delay of bursts. Finally, in order to dimension the network resources in Optical Internet backbone networks, the performance of the offset-time-based QoS scheme is evaluated for the multi-hop case. In

Multimedia Applications in Heterogeneous Internet/ATM Environments.

ERIC Educational Resources Information Center

Wolf, Lars C.

1999-01-01

Discussion of multimedia systems focuses on interaction approaches for the quality of service (QoS) architectures developed for the Internet and for asynchronous transfer mode (ATM). Highlights include interactions, videoconferencing, video on demand, a comparison of the ATM and IntServ QoS architectures, interaction models, and subordination…

7 CFR 932.150 - Modified minimum quality requirements for canned green ripe olives.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Modified minimum quality requirements for canned green... (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts... requirements for canned green ripe olives. The minimum quality requirements prescribed in § 932.52 (a)(1) of...

7 CFR 932.150 - Modified minimum quality requirements for canned green ripe olives.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Modified minimum quality requirements for canned green... (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts... requirements for canned green ripe olives. The minimum quality requirements prescribed in § 932.52 (a)(1) of...

Context-aware workflow management of mobile health applications.

PubMed

Salden, Alfons; Poortinga, Remco

2006-01-01

We propose a medical application management architecture that allows medical (IT) experts readily designing, developing and deploying context-aware mobile health (m-health) applications or services. In particular, we elaborate on how our application workflow management architecture enables chaining, coordinating, composing, and adapting context-sensitive medical application components such that critical Quality of Service (QoS) and Quality of Context (QoC) requirements typical for m-health applications or services can be met. This functional architectural support requires learning modules for distilling application-critical selection of attention and anticipation models. These models will help medical experts constructing and adjusting on-the-fly m-health application workflows and workflow strategies. We illustrate our context-aware workflow management paradigm for a m-health data delivery problem, in which optimal communication network configurations have to be determined.

Service quality in health care.

PubMed

Kenagy, J W; Berwick, D M; Shore, M F

1999-02-17

Although US health care is described as "the world's largest service industry," the quality of service--that is, the characteristics that shape the experience of care beyond technical competence--is rarely discussed in the medical literature. This article illustrates service quality principles by analyzing a routine encounter in health care from a service quality point of view. This illustration and a review of related literature from both inside and outside health care has led to the following 2 premises: First, if high-quality service had a greater presence in our practices and institutions, it would improve clinical outcomes and patient and physician satisfaction while reducing cost, and it would create competitive advantage for those who are expert in its application. Second, many other industries in the service sector have taken service quality to a high level, their techniques are readily transferable to health care, and physicians caring for patients can learn from them.

A Quality Function Deployment Framework for the Service Quality of Health Information Websites

PubMed Central

Kim, Dohoon

2010-01-01

Objectives This research was conducted to identify both the users' service requirements on health information websites (HIWs) and the key functional elements for running HIWs. With the quality function deployment framework, the derived service attributes (SAs) are mapped into the suppliers' functional characteristics (FCs) to derive the most critical FCs for the users' satisfaction. Methods Using the survey data from 228 respondents, the SAs, FCs and their relationships were analyzed using various multivariate statistical methods such as principal component factor analysis, discriminant analysis, correlation analysis, etc. Simple and compound FC priorities were derived by matrix calculation. Results Nine factors of SAs and five key features of FCs were identified, and these served as the basis for the house of quality model. Based on the compound FC priorities, the functional elements pertaining to security and privacy, and usage support should receive top priority in the course of enhancing HIWs. Conclusions The quality function deployment framework can improve the FCs of the HIWs in an effective, structured manner, and it can also be utilized for critical success factors together with their strategic implications for enhancing the service quality of HIWs. Therefore, website managers could efficiently improve website operations by considering this study's results. PMID:21818418

Managing Reputation in Contract-Based Distributed Systems

NASA Astrophysics Data System (ADS)

Baldoni, Roberto; Doria, Luca; Lodi, Giorgia; Querzoni, Leonardo

In industry practice, bilateral agreements are established between providers and consumers of services in order to regulate their business relationships. In particular, Quality of Service (QoS) requirements are specified in those agreements in the form of legally binding contracts named Service Level Agreements (SLA). Meeting SLAs allows providers to be seen in the eyes of their clients, credible, reliable, and trustworthy. This contributes to augment their reputation that can be considered an important and competitive advantage for creating potentially new business opportunities.

Factors affecting dental service quality.

PubMed

Bahadori, Mohammadkarim; Raadabadi, Mehdi; Ravangard, Ramin; Baldacchino, Donia

2015-01-01

Measuring dental clinic service quality is the first and most important factor in improving care. The quality provided plays an important role in patient satisfaction. The purpose of this paper is to identify factors affecting dental service quality from the patients' viewpoint. This cross-sectional, descriptive-analytical study was conducted in a dental clinic in Tehran between January and June 2014. A sample of 385 patients was selected from two work shifts using stratified sampling proportional to size and simple random sampling methods. The data were collected, a self-administered questionnaire designed for the purpose of the study, based on the Parasuraman and Zeithaml's model of service quality which consisted of two parts: the patients' demographic characteristics and a 30-item questionnaire to measure the five dimensions of the service quality. The collected data were analysed using SPSS 21.0 and Amos 18.0 through some descriptive statistics such as mean, standard deviation, as well as analytical methods, including confirmatory factor. Results showed that the correlation coefficients for all dimensions were higher than 0.5. In this model, assurance (regression weight=0.99) and tangibility (regression weight=0.86) had, respectively, the highest and lowest effects on dental service quality. The Parasuraman and Zeithaml's model is suitable to measure quality in dental services. The variables related to dental services quality have been made according to the model. This is a pioneering study that uses Parasuraman and Zeithaml's model and CFA in a dental setting. This study provides useful insights and guidance for dental service quality assurance.

Evaluating Service Quality from Patients' Perceptions: Application of Importance-performance Analysis Method.

PubMed

Mohebifar, Rafat; Hasani, Hana; Barikani, Ameneh; Rafiei, Sima

2016-08-01

Providing high service quality is one of the main functions of health systems. Measuring service quality is the basic prerequisite for improving quality. The aim of this study was to evaluate the quality of service in teaching hospitals using importance-performance analysis matrix. A descriptive-analytic study was conducted through a cross-sectional method in six academic hospitals of Qazvin, Iran, in 2012. A total of 360 patients contributed to the study. The sampling technique was stratified random sampling. Required data were collected based on a standard questionnaire (SERVQUAL). Data analysis was done through SPSS version 18 statistical software and importance-performance analysis matrix. The results showed a significant gap between importance and performance in all five dimensions of service quality (p < 0.05). In reviewing the gap, "reliability" (2.36) and "assurance" (2.24) dimensions had the highest quality gap and "responsiveness" had the lowest gap (1.97). Also, according to findings, reliability and assurance were in Quadrant (I), empathy was in Quadrant (II), and tangibles and responsiveness were in Quadrant (IV) of the importance-performance matrix. The negative gap in all dimensions of quality shows that quality improvement is necessary in all dimensions. Using quality and diagnosis measurement instruments such as importance-performance analysis will help hospital managers with planning of service quality improvement and achieving long-term goals.

End-to-end QoS bounds for RTP-based service subnetworks

NASA Astrophysics Data System (ADS)

Pitts, Jonathan M.; Schormans, John A.

1999-11-01

With the increasing focus on traffic prioritization to support voice-data integration in corporate intranets, practical methods are needed to dimension and manage cost efficient service partitions. This is particularly important for the provisioning of real time, delay sensitive services such as telephony and voice/video conferencing applications. Typically these can be provided over RTP/UDP/IP or ATM DBR/SBR bearers but, irrespective of the specific networking technology, the switches or routers need to implement some form of virtual buffer management with queue scheduling mechanisms to provide partitioning. The key requirement is for operators of such networks to be able to dimension the partitions and virtual buffer sizes for efficient resource utilization, instead of simply over-dimensioning. This paper draws on recent work at Queen Mary, University of London, supported by the UK Engineering and Physical Sciences Research Council, to investigate approximate analytical methods for assessing end to end delay variation bounds in cell based and packet based networks.

SOMM: A New Service Oriented Middleware for Generic Wireless Multimedia Sensor Networks Based on Code Mobility

PubMed Central

Faghih, Mohammad Mehdi; Moghaddam, Mohsen Ebrahimi

2011-01-01

Although much research in the area of Wireless Multimedia Sensor Networks (WMSNs) has been done in recent years, the programming of sensor nodes is still time-consuming and tedious. It requires expertise in low-level programming, mainly because of the use of resource constrained hardware and also the low level API provided by current operating systems. The code of the resulting systems has typically no clear separation between application and system logic. This minimizes the possibility of reusing code and often leads to the necessity of major changes when the underlying platform is changed. In this paper, we present a service oriented middleware named SOMM to support application development for WMSNs. The main goal of SOMM is to enable the development of modifiable and scalable WMSN applications. A network which uses the SOMM is capable of providing multiple services to multiple clients at the same time with the specified Quality of Service (QoS). SOMM uses a virtual machine with the ability to support mobile agents. Services in SOMM are provided by mobile agents and SOMM also provides a t space on each node which agents can use to communicate with each other. PMID:22346646

SOMM: A new service oriented middleware for generic wireless multimedia sensor networks based on code mobility.

PubMed

Faghih, Mohammad Mehdi; Moghaddam, Mohsen Ebrahimi

2011-01-01

Although much research in the area of Wireless Multimedia Sensor Networks (WMSNs) has been done in recent years, the programming of sensor nodes is still time-consuming and tedious. It requires expertise in low-level programming, mainly because of the use of resource constrained hardware and also the low level API provided by current operating systems. The code of the resulting systems has typically no clear separation between application and system logic. This minimizes the possibility of reusing code and often leads to the necessity of major changes when the underlying platform is changed. In this paper, we present a service oriented middleware named SOMM to support application development for WMSNs. The main goal of SOMM is to enable the development of modifiable and scalable WMSN applications. A network which uses the SOMM is capable of providing multiple services to multiple clients at the same time with the specified Quality of Service (QoS). SOMM uses a virtual machine with the ability to support mobile agents. Services in SOMM are provided by mobile agents and SOMM also provides a t space on each node which agents can use to communicate with each other.

32 CFR 861.4 - DOD air transportation quality and safety requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... programs and business practices that not only ensure good service but also enhance the safety, operational...) “Equivalent to the services sought by DOD” means service offered to qualify for DOD approval must be... § 861.4 DOD air transportation quality and safety requirements. (a) General. The DOD, as a customer of...

Assessing Medical Tourism Services Quality Using SERVQUAL Model: A Patient's Perspective.

PubMed

Qolipour, Mohammad; Torabipour, Amin; Faraji Khiavi, Farzad; Saki Malehi, Amal

2018-01-01

Continuous quality improvement of the hospital services is a basic requirement of medical tourism industry. The different dimensions of hospital services quality are assessed constantly to improve the service of medical tourism. The aim of this study was to determine the services quality of medical tourism in private and public hospitals. In this cross-sectional study, the quality of hospital services were assessed in view of 250 Iraqi tourists referred to Ahvaz private and public hospitals in 2015. Data were collected using a valid medical tourism SERVQUAL questionnaire (MTSQ). This questionnaire includes 8 main dimensions with 31 items. Finally, Mann-Whitney, Kruskal-Wallis and Wilcoxon tests were used to analyze the data. The mean of age of patients was 39±2.2 yr. The mean of hospital length of stay was 3.87±1.36 days. The most patients were admitted to Orthopedics, Otorhinolaryngology, Obstetrics, and Gynecology departments, respectively. There was a negative gap in all of the dimensions of service quality in the studied hospitals ( P >0.001). The highest and lowest quality gap was seen in the "exchange and travel facilities" (-2.63) and the "tangibles" (-0.68) dimension, respectively. There was a negative gap in all of the dimensions of service quality in the studied hospitals. Therefore, the hospital services quality is improved to attract the foreign patients.

QoE for telemedicine: challenges and trends

NASA Astrophysics Data System (ADS)

Cavaro-Ménard, Christine; Lu, Zhang Ge; Le Callet, Patrick

2013-09-01

Telemedicine that involves sharing of digital data (i.e. physiological signals, 2D/3D images and videos) should meet the same standards of traditional healthcare in terms of usability, accessibility, efficiency, effectiveness and quality of clinical processes. All these requirements can be seen as elementary components that participate to the quality of experience (QoE) in an ad hoc medical application scenario. Although, the quality of service (QoS) in telemedicine has been quite investigated, QoE is still lacking clear definition in this context. This later should not be assimilated to QoS as it refers clearly to the experience by the user while QoS focuses mostly on the system. QoE has a potential relevancy to optimize and understand the technical transmission chain from the final task point viewpoint which one of the most important factor for adoption of telemedicine. Towards this goal, QoE studies should be conducted with an appropriate methodology incorporating user involvement and digital data and their relation with QoS. As one of the first effort in this field, this paper proposes a survey of some key issues and solutions associated to QoE in telemedicine. We first present the services offered by telemedicine and underline the significance of QoE for tele-diagnosis and tele-surgery. Next, we identify and analyze the influencing factors such as application area, application purpose (emergency care, acquisition assistance, second opinion, education...), content type (data specificities depending on acquisition modality), context of use (offline/real time, interactivity...), and user's state (stress, expertise...), that have to be considered for a relevant QoE assessment in telemedicine.

Caching Joint Shortcut Routing to Improve Quality of Service for Information-Centric Networking.

PubMed

Huang, Baixiang; Liu, Anfeng; Zhang, Chengyuan; Xiong, Naixue; Zeng, Zhiwen; Cai, Zhiping

2018-05-29

Hundreds of thousands of ubiquitous sensing (US) devices have provided an enormous number of data for Information-Centric Networking (ICN), which is an emerging network architecture that has the potential to solve a great variety of issues faced by the traditional network. A Caching Joint Shortcut Routing (CJSR) scheme is proposed in this paper to improve the Quality of service (QoS) for ICN. The CJSR scheme mainly has two innovations which are different from other in-network caching schemes: (1) Two routing shortcuts are set up to reduce the length of routing paths. Because of some inconvenient transmission processes, the routing paths of previous schemes are prolonged, and users can only request data from Data Centers (DCs) until the data have been uploaded from Data Producers (DPs) to DCs. Hence, the first kind of shortcut is built from DPs to users directly. This shortcut could release the burden of whole network and reduce delay. Moreover, in the second shortcut routing method, a Content Router (CR) which could yield shorter length of uploading routing path from DPs to DCs is chosen, and then data packets are uploaded through this chosen CR. In this method, the uploading path shares some segments with the pre-caching path, thus the overall length of routing paths is reduced. (2) The second innovation of the CJSR scheme is that a cooperative pre-caching mechanism is proposed so that QoS could have a further increase. Besides being used in downloading routing, the pre-caching mechanism can also be used when data packets are uploaded towards DCs. Combining uploading and downloading pre-caching, the cooperative pre-caching mechanism exhibits high performance in different situations. Furthermore, to address the scarcity of storage size, an algorithm that could make use of storage from idle CRs is proposed. After comparing the proposed scheme with five existing schemes via simulations, experiments results reveal that the CJSR scheme could reduce the total number of

The Massification of Higher Education in the UK: Aspects of Service Quality

ERIC Educational Resources Information Center

Giannakis, Mihalis; Bullivant, Nicola

2016-01-01

This article explores several aspects of service quality for the provision of higher education. Alongside the trend of the massification of higher education over the past two decades, higher education institutions are required to review quality across a range of outputs, besides teaching and learning. The study was undertaken within the…

The Quality of Educational Services from Students' Viewpoint in Iran: A Systematic Review and Meta-analysis.

PubMed

Moosavi, Ahmad; Mohseni, Mohammad; Ziaiifar, Hajar; Azami-Aghdash, Saber; Gharasi Manshadi, Mahdi; Rezapour, Aziz

2017-04-01

Students' view is an important factor in assessing the quality of universities. Servqual pattern is regarded as the most prominent for services quality measurement. This study aimed to review systematically studies that investigated the quality of educational services. A systematic review and meta-analysis of studies evaluating students' viewpoint about quality of educational services were conducted. Required data were collected from PubMed, Embase, Scopus, Science Direct, Google Scholar, SID, Magiran, and Iranmedex, without time restriction. Computer software CMA, ver. 2 was applied to estimate the total mean score of students' perception and expectation of services quality and the gap between them. The 18 eligible studies were entered into study. The studies were conducted between 2004 and 2014. Based on the random effect model, the total mean score of students' perception, students' expectation and the gap between them were estimated 2.92 (95% CI, 2.75 - 3.09), 4.18 (95% CI, 3.98 - 4.38), respectively and -1.30 (95% CI= -1.56, -1.04). The studied students' expectation level is higher than the current quality of educational services. There is a tangible difference between their expectations and the current quality, which requires officials' efforts to improve quality in all dimensions and effective steps can be taken towards improving the quality of educational services through appropriate training planning and training for empowering employees in colleges and universities.

Cognitive radio adaptation for power consumption minimization using biogeography-based optimization

NASA Astrophysics Data System (ADS)

Qi, Pei-Han; Zheng, Shi-Lian; Yang, Xiao-Niu; Zhao, Zhi-Jin

2016-12-01

Adaptation is one of the key capabilities of cognitive radio, which focuses on how to adjust the radio parameters to optimize the system performance based on the knowledge of the radio environment and its capability and characteristics. In this paper, we consider the cognitive radio adaptation problem for power consumption minimization. The problem is formulated as a constrained power consumption minimization problem, and the biogeography-based optimization (BBO) is introduced to solve this optimization problem. A novel habitat suitability index (HSI) evaluation mechanism is proposed, in which both the power consumption minimization objective and the quality of services (QoS) constraints are taken into account. The results show that under different QoS requirement settings corresponding to different types of services, the algorithm can minimize power consumption while still maintaining the QoS requirements. Comparison with particle swarm optimization (PSO) and cat swarm optimization (CSO) reveals that BBO works better, especially at the early stage of the search, which means that the BBO is a better choice for real-time applications. Project supported by the National Natural Science Foundation of China (Grant No. 61501356), the Fundamental Research Funds of the Ministry of Education, China (Grant No. JB160101), and the Postdoctoral Fund of Shaanxi Province, China.

Are stipulated requirements for the quality of maternity care complied with?

PubMed

Johansen, Lars T; Pay, Aase Serine Devold; Broen, Lise; Roland, Brit; Øian, Pål

2017-09-19

The Directorate of Health’s national guide Et trygt fødetilbud – kvalitetskrav til fødselsomsorgen [A safe maternity service – requirements regarding the quality of maternity care] was published in December 2010 and was intended to provide a basis for an improved and more predictable maternity service. This article presents data from the maternity institutions on compliance with the quality requirements, including information on selection, fetal monitoring, organisation, staffing and competencies. The information was acquired with the aid of an electronic questionnaire in the period January–May 2015. The form was sent by e-mail to the medical officer in charge at all maternity units in Norway as at 1 January 2015 (n=47). There was a 100 % response to the questionnaire. The criteria for selecting where pregnant women should give birth were stated to be in conformity with the quality requirements. Some maternity institutions failed to describe the areas of responsibilities of doctors and midwives (38.5 % and 15.4 %, respectively). Few institutions recorded whether the midwife was present with the patient during the active phase. Half of the maternity departments (level 2 birth units) reported unfilled doctors’ posts, and a third of the university hospitals/central hospitals (level 1 birth units) reported a severe shortage of locum midwives. Half of the level 2 birth units believed that the quality requirements had resulted in improved training, but reported only a limited degree of interdisciplinary or mandatory instruction. The study reveals that there are several areas in which the health enterprises have procedures that conform to national quality requirements, but where it is still unclear whether they are observed in practice. Areas for improvement relate to routines describing areas of responsibility, availability of personnel resources and staff training.

Service quality framework for clinical laboratories.

PubMed

Ramessur, Vinaysing; Hurreeram, Dinesh Kumar; Maistry, Kaylasson

2015-01-01

The purpose of this paper is to illustrate a service quality framework that enhances service delivery in clinical laboratories by gauging medical practitioner satisfaction and by providing avenues for continuous improvement. The case study method has been used for conducting the exploratory study, with focus on the Mauritian public clinical laboratory. A structured questionnaire based on the SERVQUAL service quality model was used for data collection, analysis and for the development of the service quality framework. The study confirms the pertinence of the following service quality dimensions within the context of clinical laboratories: tangibility, reliability, responsiveness, turnaround time, technology, test reports, communication and laboratory staff attitude and behaviour. The service quality framework developed, termed LabSERV, is vital for clinical laboratories in the search for improving service delivery to medical practitioners. This is a pioneering work carried out in the clinical laboratory sector in Mauritius. Medical practitioner expectations and perceptions have been simultaneously considered to generate a novel service quality framework for clinical laboratories.

Quantitative comparison of measurements of urgent care service quality.

PubMed

Qin, Hong; Prybutok, Victor; Prybutok, Gayle

2016-01-01

Service quality and patient satisfaction are essential to health care organization success. Parasuraman, Zeithaml, and Berry introduced SERVQUAL, a prominent service quality measure not yet applied to urgent care. We develop an instrument to measure perceived service quality and identify the determinants of patient satisfaction/ behavioral intentions. We examine the relationships among perceived service quality, patient satisfaction and behavioral intentions, and demonstrate that urgent care service quality is not equivalent using measures of perceptions only, differences of expectations minus perceptions, ratio of perceptions to expectations, and the log of the ratio. Perceptions provide the best measure of urgent care service quality.

Total Quality Management and Media Services: The Deming Method.

ERIC Educational Resources Information Center

Richie, Mark L.

1992-01-01

W. Edwards Deming built a 40-year record of quality management in Japan known as Total Quality Management (TQM). His 14 points require a change in the belief system of managers and media directors, but their implementation in government agencies and schools will produce increased time for better services, better communications, and new programs.…

Modeling and Analysis of Hybrid Cellular/WLAN Systems with Integrated Service-Based Vertical Handoff Schemes

NASA Astrophysics Data System (ADS)

Xia, Weiwei; Shen, Lianfeng

We propose two vertical handoff schemes for cellular network and wireless local area network (WLAN) integration: integrated service-based handoff (ISH) and integrated service-based handoff with queue capabilities (ISHQ). Compared with existing handoff schemes in integrated cellular/WLAN networks, the proposed schemes consider a more comprehensive set of system characteristics such as different features of voice and data services, dynamic information about the admitted calls, user mobility and vertical handoffs in two directions. The code division multiple access (CDMA) cellular network and IEEE 802.11e WLAN are taken into account in the proposed schemes. We model the integrated networks by using multi-dimensional Markov chains and the major performance measures are derived for voice and data services. The important system parameters such as thresholds to prioritize handoff voice calls and queue sizes are optimized. Numerical results demonstrate that the proposed ISHQ scheme can maximize the utilization of overall bandwidth resources with the best quality of service (QoS) provisioning for voice and data services.

Service Quality Assessment Scale (SQAS): An Instrument for Evaluating Service Quality of Health-Fitness Clubs

ERIC Educational Resources Information Center

Lam, Eddie T. C.; Zhang, James J.; Jensen, Barbara E.

2005-01-01