User Quality Of Service Requirements Research Articles

Web Service Selection Based on Ranking of QOS Using Associative Classification

With the explosive growth of the number of services published over the Internet, it is difficult to select satisfactory web services among the candidate web services which provide similar functionalities. Quality of Service (QoS) is considered as the most important non-functional criterion for service selection. But this criterion is no longer considered as the only criterion to rank web services, satisfying user's preferences. The similarity measure (outputs-inputs similarity) between concepts based on ontology in an interconnected network of semantic Web services involved in a composition can be used as a distinguishing criterion to estimate the semantic quality of selected services for the composite service. Coupling the semantic similarity as the functional aspect and quality of services allows us to further constrain and select services for the valid composite services. In this paper, we present an overall service selection and ranking framework which firstly classify candidate web services to different QoS levels respect to user's QoS requirements and preferences with an Associative Classification algorithm and then rank the most qualified candidate services based on their functional quality through semantic matching. The experimental results show that proposed framework can satisfy service requesters' non-functional requirements.

Multi-robot navigation based QoS routing in self-organizing networks

The technical development drives the future networks to become large-scale, heterogeneous, and dynamic. Bio-inspired networking can help reduce the time-space complexity of the complex network. Due to the good features such as self-organization and self-management, self-organizing network (SON) will most probably be a priority choice for the next generation network. In this paper, a swarm intelligence based Quality of Service (QoS) routing protocol is proposed for SON. The inaccurate routing and QoS information is described with fuzzy mathematics whilst the utilities of both the user and the network service provider are considered by applying game theory. Based on the multi-robot navigation algorithm, the protocol is able to search a routing path which can satisfy the user QoS requirements and achieve the Pareto optimal utilities of the user and the network service provider under Nash equilibrium. The proposed protocol is implemented and evaluated by extensive simulation experiments. The results show that it beats both other swarm intelligence based routing protocols and the traditional Dijkstra algorithm based routing protocol. The searched routing paths support the win–win effect for both the user and the network service provider.

An ant colony-based multi objective quality of service routing for mobile ad hoc networks

Routing, the act of moving information from a source node to a destination node across any kind of network is one of the major issues in computer network literature. Ad hoc wireless networks are increasing in popularity, because of the spread of laptops, sensor devices, personal digital assistants, and other mobile electronic devices. These devices will eventually need to communicate with each other, without an adequate infrastructure to rely on. For mobile ad hoc networks, the complexity of routing increases because of its characteristics such as dynamic topology, absence of centralized authority, time varying quality of service (QoS) requirements, etc. The biggest challenge in this kind of networks is to find a path between communication end points satisfying user's QoS requirement in spite of frequent path failures because of node mobility. Recent advances in wireless technology and availability of mobile computing devices with networking capabilities have generated a lot of interest in wireless ad hoc networks for QoS-based real-time multimedia applications. In this article, we are proposing AMQR, an ant-based multiobjective on demand QoS routing algorithm for mobile ad hoc network which will be highly adaptive, efficient, scalable, and mainly reduces end-to-end delay in high mobility cases.

Call Admission Control with Resource Reservation for OFDM Networks

The scarcity of the radio resources and variable channel quality cause many challenges to the resource management for future all-IP wireless communications. One technique to guarantee a certain level of quality of service (QoS) is call admission control (CAC). Briefly, CAC is a mechanism which decides whether a new call could be admitted or rejected depending on its impacts on the current calls’ QoS. Conventional CACs such as guard channel, channel borrowing and queuing priority techniques only consider the instantaneous radio resource availabilities to make a decision on admission problem, thus they are neither able to prevent the network congestion problem nor meet the QoS requirements of different users with multi-service requirements. In this work, we propose a new CAC technique with a future look into the needed extra resources through a reservation technique to offset the changes of the channel condition due to mobility. We show that during a call session, the needed radio resources may be increased compared with the negotiated resources during call setup. Although such fluctuations are fairly low for a single call, it is not negligible when the network is congested. As a result, some ongoing calls may experience QoS degradation. We show that such a consideration is critical in orthogonal frequency division multiplexing (OFDM) wireless networks such as 3GPP LTE where the radio resources are assigned to the users depending on the channel quality. The study assumes two types of applications denoted by wide-band and narrow-band and the performance of the proposed algorithm is modeled through queuing theory and event-driven simulation approaches. The results show that such a reservation technique improves the call admission performance significantly in terms of call blocking, call drop and call QoS degradation probabilities, and it outperforms the conventional CACs with insignificant loss in network capacity.

Modeling and analysis of the effects of QoS and reliability on pricing, profitability, and risk management in multiperiod grid-computing networks

In this paper we develop a network equilibrium model for optimal pricing and resource allocation in Computational Grid Network. We consider a general network economy model with Grid Resource Providers, Grid Resource Brokers and Grid Users. The proposed framework allows for the modeling and theoretical analysis of Computational Grid Markets that considers a non-cooperative behavior of decision-makers in the same tier of the grid computing network (such as, for example, Grid Resource Providers) as well as cooperative behavior between tiers (between Resource Providers and Grid Brokers). We introduce risk management into the decision making process by analyzing the decision-marker's reliability and quality of service (QoS) requirement. We analyze resource allocation patterns as well as equilibrium price based on demand, supply, and cost structure of the grid computing market network. We specifically answer the following questions with several numerical examples: How do system reliability levels affect the QoS levels of the service providers and brokers under competition? How do system reliability levels affect the profits of resource providers and brokers in a competitive market? How do system reliability levels influence the pricing of the services in a competitive environment? How do users' service request types, QoS requirements, and timing concerns affect users' behaviors, costs and risks in equilibrium? How does the market mechanism allocate resources to satisfy the demands of users? We find that for users who request same services certain timing flexibility can not only reduce the costs but also lower the risks. The results indicated that the value of QoS can be efficiently priced based on the heterogeneous service demands.

Impact of CSI on Radio Resource Management Techniques for the OFDMA downlink

Adaptive resource allocation can drastically increase the throughput of an Orthogonal Frequency Division Multiple Access (OFDMA) system when the Channel State Information (CSI) is accurately known. Unfortunately, in practice, perfect CSI is rarely possible. In this paper, we consider adaptive sub-carrier assignment for downlink multiuser OFDMA systems, where the transmitter has no knowledge of the instantaneous channel realizations. The problem we address is maximizing the sum-capacity of the system subject to user Quality of Service (QoS) requirements. A heuristic algorithm presented in \cite{Zhang06} is modified in order to provide an enhanced sub-optimal solution. Numerical results show that resources can be adaptively allocated using statistical CSI (SCSI) and that such an approach allows for an important number of user QoS requirements to be met. Comparisons between the instantaneous CSI (ICSI) and SCSI based resource allocation schemes demonstrate that their performance difference is highly dependent on the number of active users present in the cell, the QoS constraint, and the transmit power.

Advances in cooperative wireless networking: Part I [Guest Editorial

Over the last few years, fundamental research has demonstrated the great potential of cooperative wireless networking in increasing system capacity and enlarging the coverage area as well as enhancing quality of service (QoS) by taking advantage of cooperative diversity and multiplexing. Consequently, cooperative wireless networking has become one of the widely recognized features for future wireless communication systems. While the conventional research mainly focuses on relatively simple cooperative relay topologies or cooperation schemes under the existing infrastructure networks, cooperative networking for future wireless systems has a unique spectrum of features. Specifically, the frequent user cooperation and interaction empower mobile users with a new role as mobile service providers, in contrast to their traditional role as only consumers. In this sense, mobile users' cooperation strategy and decisions are sensitive to not only the QoS requirements of the end users' applications, but also their own benefits as rewards for providing mobile services. Moreover, the cooperation provided by mobile users does not have to rely heavily on infrastructure networks.

Bandwidth allocation in cooperative wireless networks: Buffer load analysis and fairness evaluation

In modern cooperative wireless networks, the resource allocation is an issue of major significance. The cooperation of source and relay nodes in wireless networks towards improved performance and robustness requires the application of an efficient bandwidth sharing policy. Moreover, user requirements for multimedia content over wireless links necessitate the support of advanced Quality of Service (QoS) features. In this paper, a novel bandwidth allocation technique for cooperative wireless networks is proposed, which is able to satisfy the increased QoS requirements of network users taking into account both traffic priority and packet buffer load. The performance of the proposed scheme is examined by analyzing the impact of buffer load on bandwidth allocation. Moreover, fairness performance in resource sharing is also studied. The results obtained for the cooperative network scenario employed, are validated by simulations. Evidently, the improved performance achieved by the proposed technique indicates that it can be employed for efficient traffic differentiation. The flexible design architecture of the proposed technique indicates its capability to be integrated into Medium Access Control (MAC) protocols for cooperative wireless networks.

Network-aware meta-scheduling in advance with autonomous self-tuning system

The provision of Quality of Service (QoS) in Grid environments is still an open issue that needs attention from the research community. One way of contributing to the provision of QoS in Grids is by performing meta-scheduling of jobs in advance, that is, jobs are scheduled some time before they are actually executed. In this way, it becomes more likely that the appropriate resources are available to run the job when needed, so that QoS requirements of jobs are met (i.e. jobs are finished within a deadline). This paper presents a framework built on top of Globus and the GridWay meta-scheduler to provide QoS by means of performing meta-scheduling in advance. Thanks to this, QoS requirements of jobs are met. This framework manages idle/busy periods of resources in order to choose the most suitable resource for each job, and uses red–black trees for this task. Besides, no prior knowledge on the duration of jobs is required, as opposed to other works using similar techniques. This framework uses heuristics that consider the network as a first level resource. Furthermore, this framework presents an autonomous behaviour so that it adapts to the dynamic changes of the Grid resources. The autonomous behaviour is obtained by means of computing a trust for each resource and performing job rescheduling. All this set of features make this framework suitable for real Grids. Finally, a performance evaluation using a real testbed is presented that illustrates the efficiency of this approach to meet the QoS requirements of users.

Extended proportional fair scheduling for statistical QoS guarantee in wireless networks

Opportunistic scheduling provides the capability of resource management in wireless networks by taking advantage of multiuser diversity and by allowing delay variation in delivering data packets. It generally aims to maximize system throughput or guarantee fairness and quality of service (QoS) requirements. In this paper, we develop an extended proportional fair (PF) scheduling policy that can statistically guarantee three kinds of QoS. The scheduling policy is derived by solving the optimization problems in an ideal system according to QoS constraints. We prove that the practical version of the scheduling policy is optimal in opportunistic scheduling systems. As each scheduling policy has some parameters, we also consider practical parameter adaptation algorithms that require low implementation complexity and show their convergences mathematically. Through simulations, we confirm that our proposed schedulers show good fairness performance in addition to guaranteeing each user's QoS requirements.

Cross-Layer Resource Allocation for Mixed Services in Multiuser OFDM-Based Cognitive Radio Systems

We study the resource-allocation problem in a multiuser orthogonal frequency-division multiplexing (OFDM)-based cognitive radio (CR) system using a cross-layer approach. The goal is to provide satisfactory quality of service (QoS) to both real-time and non-real-time applications, despite the rapid variations in available resources caused by the activities of the primary users. The dynamic nature of the available spectrum gives rise to two resource allocation issues: 1) problem feasibility and 2) false urgency. To solve the problem-feasibility issue, which arises when resources are insufficient to meet all user QoS requirements, we adopt a goal-programming approach. The false-urgency issue that was caused by variations in available system resources is effectively avoided by a proposed rate-requirement calculation mechanism based on the status of the packets in queue and system resource availability. Simulation results show that the proposed cross-layer resource-allocation algorithm for CR systems performs better than existing algorithms that were designed for multiuser OFDM systems.

Cross Layer QoS Guarantees in Multiuser WLAN Systems

The use of real-time delay-sensitive applications in wireless systems has significantly increased during the last years. Consequently, the demand to guarantee certain Quality of Service (QoS) is a challenging issue for the system's designers. A cross-layer based dynamically tuned queue length scheduler is presented in this paper, for the Downlink of multiuser WLAN systems with heterogeneous traffic requirements. An opportunistic scheduling algorithm is applied, while users from higher priority traffic classes are prioritized. A trade-off between the throughput maximization of the system and the guarantee of the users QoS requirements is obtained. Therefore the length of the queue is dynamically adjusted to select the appropriate conditions based on the operator requirements.

Fair Class-Based Downlink Scheduling with Revenue Considerations in Next Generation Broadband Wireless Access Systems

The success of emerging Broadband Wireless Access Systems (BWASs) will depend, among other factors, on their ability to manage their shared wireless resources in the most efficient way. This is a complex task due to the heterogeneous nature, and hence, diverse Quality of Service (QoS) requirements of different applications that these systems support. Therefore, QoS provisioning is crucial for the success of such wireless access systems. In this paper, we propose a novel downlink packet scheduling scheme for QoS provisioning in BWASs. The proposed scheme employs practical economic models through the use of novel utility and opportunity cost functions to simultaneously satisfy the diverse QoS requirements of mobile users and maximize the revenues of network operators. Unlike existing schemes, the proposed scheme is general and can support multiple QoS classes with users having different QoS and traffic demands. To demonstrate its generality, we show how the utility function can be used to support three different types of traffic, namely best-effort traffic, traffic with minimum data rate requirements, and traffic with maximum packet delay requirements. Extensive performance analysis is carried out to show the effectiveness and strengths of the proposed packet scheduling scheme.

Performance evaluation of utility‐based scheduling schemes with QoS guarantees in IEEE 802.16/WiMAX systems

AbstractOne of the most important benefits that WiMAX technology brings, the ability to provide differentiated quality of service (QoS) guarantees, could also prove to be the largest problem for system designers, because scheduling mechanisms able to cope with these demands have not been explicitly defined in the standard. In order to facilitate the understanding of how various scheduling schemes perform in a real system, we present here a detailed performance evaluation of some utility‐based scheduling algorithms, covering aspects like fairness and QoS provisioning. Through a series of extensive simulations, we analyse the ability of the scheduling schemes considered to strike a balance between fairness among users, or more restrictively, user QoS requirement satisfaction, and system efficiency maximization. Further, we show how several simple algorithms could be used as building blocks, constructing a powerful mechanism that allows the system designer to obtain any desired system behaviour, or even to dynamically change from one profile to another, depending on specific network‐related conditions. More specifically, by combining the benefits of proportional fair (PF) scheduling with the highly desirable system capacity maximization, and also taking into account a peak‐to‐average (PTA) channel quality metric, we are able to define a rule that outperforms traditional scheduling schemes, copes with various network conditions and provides graceful service degradation. Our results indicate that, by exploiting the intrinsic properties of orthogonal frequency division multiple access (OFDMA) as well as the mechanisms of the WiMAX system that are not regulated by the standard, one could increase the system efficiency, while fully respecting the QoS guarantees imposed. The use of algorithms that provide graceful performance degradation is highly advisable, in order to be able to employ a non‐conservative call admission control (CAC) mechanism, which further improves the overall spectral efficiency by maintaining the system close to saturation at all times. Copyright © 2009 John Wiley & Sons, Ltd.

Nonlinear and Linear Broadcasting With QoS Requirements: Tractable Approaches for Bounded Channel Uncertainties

We consider the downlink of a cellular system in which the base station employs multiple transmit antennas, each receiver has a single antenna, and the users specify certain quality of service (QoS) requirements. We study the design of robust broadcasting schemes that minimize the transmission power necessary to guarantee that the QoS requirements are satisfied for all channels within bounded uncertainty regions around the transmitter's estimate of each user's channel. Each user's QoS requirement is formulated as a constraint on the mean square error (MSE) in its received signal, and we show that these MSE constraints imply constraints on the received signal-to-interference-plus-noise ratio. Using the MSE constraints, we present a unified approach to the design of linear and nonlinear transceivers with QoS requirements that must be satisfied in the presence of bounded channel uncertainty. The proposed designs overcome the limitations of existing approaches that provide conservative designs or are only applicable to the case of linear precoding. Furthermore, we provide computationally efficient design formulations for a rather general model of bounded channel uncertainty that subsumes many natural choices for the uncertainty region. We also consider the problem of the robust counterpart to precoding schemes that maximize the fidelity of the weakest user's signal subject to a power constraint. For this problem, we provide quasi-convex formulations, for both linear and nonlinear transceivers, that can be efficiently solved using a one-dimensional bisection search. Our numerical results demonstrate that in the presence of bounded uncertainty in the transmitter's knowledge of users' channels, the proposed designs provide guarantees for a larger range of QoS requirements than the existing approaches that are based on bounded channel uncertainty models and require less transmission power to provide these guarantees.

Policy‐based scanning with QoS support for seamless handovers in wireless networks

AbstractSupporting seamless handovers between different wireless networks is a challenging issue. One of the most important aspects of a seamless handover is finding a target network and point of attachment (PoA). This is achieved by performing a so‐called channel scanning. In most handovers, such as between universal mobile telecommunications system (UMTS), wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX), channel scanning causes severe service disruptions with the current PoA and degrades the quality of service (QoS) during the handover. In this paper, a new architecture for QoS supported scanning that can be generalized to different wireless networks is proposed. It employs two techniques. The first is for determining a policy‐based order for the channel scanning sequence. With this technique, depending on the network costs and user requirements, the policy engine determines the channel scanning order for different network types and sets up a scanning sequence of PoAs for a given network type. This policy‐based scanning order provides a faster discovery of the target PoA that meets the QoS demands of the user. The second technique consists of a QoS supported dynamic scanning algorithm where the scanning frequency and duration are determined based on the user QOS requirements. Most importantly, the scanning duration is scheduled to guarantee the user QoS requirements while the scan progresses. Simulation results show that the proposed mechanism achieves relatively short service disruptions and provides the desired quality to users during the scanning period. Copyright © 2009 John Wiley & Sons, Ltd.

Scheduling Algorithm to Provide QoS over a Shared Wireless Link

Several scheduling algorithms have been proposed for the downlink of a Code Division Multiple Access (CDMA) system with High Data Rate (HDR). Modified Largest Weighted Delay First (M-LWDF) scheduling algorithm selects a user according to the user current channel condition, user head-of-line packet delay and user Quality of Service (QoS) requirement. Proportional Fair (PF) scheduling algorithm has also been proposed for CDMA/HDR system and it selects a user according to the ratio of the user current channel rate and the user average channel rate, which provides good performance in terms of fairness. However, when variable bit rate (VBR) traffic is considered under different channel conditions for each user, both schedulers' performance decrease. M-LWDF scheduler can not guarantee the QoS requirement to be achieved and PF scheduler can not achieve a good fairness among the users. In this work, we propose a new scheduling algorithm to enhance M-LWDF and PF schedulers performance. Proposed scheduler selects a user according to the user input traffic characteristic, user current channel condition and user QoS requirement, which consists of a delay value with a maximum violation probability. We consider the well-known effective bandwidth expression, which takes into account the user QoS requirement and the user input traffic characteristics, to select a user to be scheduled. Properties of the proposed scheduling algorithm are investigated through simulations with constant bit rate (CBR) and VBR flows and performance comparisons with M-LWDF and PF schedulers. The results show a better performance of the proposed scheduler compared with M-LWDF and PF schedulers.

A Fuzzy Integral and Game Theory Based QoS Multicast Routing Scheme

PDF HTML阅读 XML下载 导出引用 引用提醒 基于模糊积分和博弈论的QoS组播路由机制 DOI: 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: Supported by the National Natural Science Foundation of China under Grant Nos.60673159, 70671020 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant No.2006AA01Z214 (国家高技术研究发展计划(863)); the Program for New Century Excellent Talents in University of China under Grant No.NCET-05-0289 (新世纪优秀人才支持计划); the Key Project of Chinese Ministry of Education under Grant No.108040 (国家教育部科学技术研究重点项目); the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20060145012 (高等学校博士学科点专项科研基金); the Natural Science Foundation of Liaoning Province of China under Grant No.20062022 (辽宁省自然科学基金) A Fuzzy Integral and Game Theory Based QoS Multicast Routing Scheme Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:下一代互联网NGI(next generation Internet)需要提供服务质量QoS(quality of service)路由能力.由于NGI网络状态难以精确测量与表达,因此,QoS路由基于的信息应该是模糊的.随着网络运营的渐趋商业化,付费上网要求实现QoS计费,而网络提供方与用户的利益冲突要求实现效用双赢.设计了一种基于模糊积分和博弈论的QoS组播路由机制.该机制由边评判、博弈分析和组播路由树建立算法组成,基于模糊积分和适合隶属度函数对边进行模糊综合评判,通过博弈分析确定网络提供方与用户在边上的效用能否达到Nash均衡,通过组播路由树建立算法使得在建立的组播路由树上不仅用户QoS要求得到满足,而且网络提供方效用与用户效用达到或接近Nash均衡下的Pareto最优.仿真结果表明,与QoSMIC等机制相比,该机制具有较好的性能. Abstract:QoS (quality of service) multicast routing is essential to NGI (next generation Internet). On one hand, due to difficulty in exact measurement and expression of NGI network status, the necessary QoS routing information should be fuzzy. On the other hand, with the gradual commercialization of network operation, paying for network usage calls for QoS pricing and accounting. However, benefit conflicts between network providers and users ask the so-called both-win to be supported. Thus, a fuzzy integral and game theory based QoS multicast routing scheme is proposed and has been implemented by simulation. It consists of three parts: Edge evaluation, game analysis, and multicast tree construction. It does comprehensive evaluation on candidate edges based on fuzzy integral and adaptability membership degree functions for edge parameters, determines whether Nash equilibrium between network provider utility and user utility has been achieved on candidate edges by gaming analysis, and attempts to construct a multicast routing tree with not only user QoS requirements satisfied but also Pareto optimum under Nash equilibrium on network provider utility and user utility achieved or approached by the proposed algorithm. Simulation results show that performance of the proposed scheme is better than that of some well known schemes, including QoSMIC. 参考文献 相似文献 引证文献

Routing-oriented update schEme (ROSE) for link state updating

Few works have been reported to address the issue of updating link state information in order to effectively facilitate quality-of-service (QoS) routing. The idea of modeling the QoS link state information as random variables has been reported, but none of the existing works have provided a comprehensive probabilistic approach to link state update that takes the probability density functions of both the user's QoS requirements and the network's QoS measurements into account. We propose the routing-oriented update scheme (ROSE) that utilizes the knowledge of the history of network operations and user's QoS requirements to improve the efficiency of link state update without increasing the network overhead. ROSE is a new class-based link state update scheme which intelligently determines class sizes to minimize the impact of inaccurate link state information. Through theoretical analysis and extensive simulations, we demonstrate that ROSE outperforms other class- based link state update policies.

Cross-Layer-Model Based Adaptive Resource Allocation for Statistical QoS Guarantees in Mobile Wireless Networks

We propose a cross-layer-model based adaptive resource-allocation scheme for the diverse quality-of-service (QoS) guarantees over downlink mobile wireless networks. Our proposed scheme dynamically assigns power-levels and time- slots for heterogeneous real-time mobile users to satisfy the variation of statistical delay-bound QoS requirements. To achieve this goal, we apply Wu and Negi's effective capacity approach to derive the admission-control and power/time-slot allocation algorithms, guaranteeing the statistical delay-bound for heterogeneous mobile users. When designing such an algorithm, we study the impact of physical-layer issues such as adaptive power-control and channel-state information (CSI) feedback delay on the QoS provisioning performance. Through numerical and simulation results, we observe that the adaptive power adaptation has a significant impact on statistical QoS-guarantees. In addition, the analyses indicate that our proposed resource-allocation algorithms are shown to be able to efficiently support the diverse QoS requirements for various real-time mobile users over different wireless channels. Also, in an in-door mobile environment, e.g., the widely used wireless local-area networks (WLAN), our proposed algorithm is shown to be robust to the CSI feedback delay.