Flow-Based Service Selection forWeb Service Composition Supporting Multiple QoS Classes

In an asynchronous transfer mode (ATM) network multimedia environment, the bandwidth efficiency can be improved by defining multiple quality of service (QOS) classes and using a traffic control which manages required QOS of each class individually (QOS control). Priority assignment control is presented as a QOS control method in an ATM switching node. To quantitatively evaluate the control performance, the region determined by the offered load of each class where the QOS requirements of all the classes are satisfied is analytically obtained and various combinations of two classes and related control effects are discussed. When required values of cell loss rate and delay time are both different between the classes, the control effect is large; however, when only either of them is different, the effect is relatively small. The control scheme to enlarge the actual admissible offer load region by adaptively changing the priority assignment ratio is presented and its feasibility is confirmed by the simulation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Web service composition is a promising solution for building distributed applications on the e-business processes, and with web services providing similar functional characteristics, Quality of Service (QoS) is the main factor to differentiate them. It is imperative to provide service consumers with facilities for selecting the only web services for their requirement according to their non-functional characteristics or QoS. However, the selection process is too greatly complicated to meet the requirement of business process. In this paper, the key business process performance model (KBPP) is proposed, and further, the issue of QoS driven service selection for dynamic web service composition is investigated. From the point of view of requirement of KBPP, an evaluation framework with KBPP is proposed, and a new approach to optimize the service selecting based on KBPP is presented. Experimental results show that the proposed approach greatly improves the service selection process in a dynamic and uncertain environment of web services. Simulative experiments are conducted to show the validity and efficiency of the methods.

With the rapid development of e-commerce over Internet, web services have attracted much attention in recent years. Nowadays, enterprises are able to outsource their internal business processes as services and make them accessible via the Web. Then they can dynamically combine individual services to provide new value-added services. With the increasing number of web services having equivalent functionality, the binding procedure is driven by some non-functional, Quality of Service (QoS) criteria, such as the money cost, response time, reputation, reliability or a trade-off between them. Thus, an important problem is, given QoS constraints, how to aggregate and leverage individual service’s QoS information to derive the optimal QoS of the composite service. In this paper, we propose a novel QoS model for performing flexible service selection. The key idea of the model is to relax users’ QoS constraints and try to find the most possible services satisfying users’ QoS requirements. Based on the proposed QoS framework, we develop various algorithms for making service selection on individual and composite services. We also introduce a top-k ranking strategy to reflect a user’s personalized requirements. Experimental evaluation shows the proposed QoS model is efficient and practical.

This research aimed to measure the level of quality of academic advising and student support services from the perspective of students of Preparatory Year at the University of Najran. To achieve this, the descriptive analytical method was followed by administering a questionnaire consisting of (37 items) which were distributed over four dimensions (the academic advisor – the quality of the academic support for outstanding and struggling students – the quality of supporting talented and creative students – the quality of complaints and suggestions services). The sample consisted of (300) students selected from among the preparatory year at the University of Najran. The results indicated that the level of quality of academic advising services and student support services was (medium level) with a mean of (2.24). There were statistically significant differences at (α = 0.05) in the level of quality of academic services and student support services according to the level (first-second) in favor of the second level. There were also differences in the level of academic advising and student support services according to student status at (α = 0.05) in favor of struggling students. Results also indicated that there were no statistically significant differences in the students' assessment of the quality of services due to the gender variable. The study concluded that academic advising services need more efforts to improve the quality of services, especially in providing the necessary support to students, as well as the services for gifted and creative students, complaints and suggestions services. The study recommended the need to adopt clear mechanisms for academic advising and student support through which these services can be provided to all student categories and to evaluate the quality of these services.&#x0D; Keywords: academic advising, preparatory year, quality, Najran University.

To meet the energy-saving requirements of user equipment (UE) operating in Radio Resource Control idle/inactive states (RRC_IDLE/RRC_INACTIVE) in the 3rd-Generation Partnership Project (3GPP) 5G-Advanced (5G-A) networks, the New Radio (NR) downlink paging procedure relies on periodic monitoring and frequent synchronization signal block (SSB) measurements, which wastes energy when no paging arrivals occur. Meanwhile, heterogeneous Quality of Service (QoS) constraints make it difficult for fixed-parameter Idle Discontinuous Reception and Paging Early Indication mechanisms (IDRX/PEI) to balance energy, delay, and reliability. This paper develops a UAV-assisted 5G-A paging control framework that maps services into multiple QoS classes and models QoS violation risk and system energy consumption under unified accounting, including UE monitoring/reception energy and unmanned aerial vehicle (UAV) forwarding energy. We then propose a QoS-aware risk-driven paging strategy: an offline Long Short-Term Memory (LSTM) predictor is trained to estimate the time-to-next-arrival (TTNA) of paging events and produce a bounded urgency/risk signal to initialize class-dependent thresholds, while online triggering and QoS-feedback-based threshold adaptation regulate the empirical violation rate toward target constraints under varying loads, enabling a controllable energy–delay trade-off. A simulation-based evaluation is conducted to compare the proposed method with representative baselines (Enhanced Paging Monitoring (EPM), Split Paging Occasion (SPOP), and Predicted Paging Early Indication (PPEI)) and to examine the impact of SSB overhead and UAV relaying on the energy–delay–reliability trade-offs.

The upcoming teleservices in mobile networks require quality of service (QoS) support, which have to be considered during the radio access network (RAN) planning. QoS becomes one of the most important points for the network planning process. Mobile network providers that want to offer information services based on QoS, have to plan their networks and their network capacity according to user demands. Traditional RAN planning tools consider only best effort service for all applications since RANs were not able to guarantee QoS before release 99 of 3GPP specifications. This has consequences in network planning and user satisfaction; therefore it is necessary to take the QoS requirements of each application of every user into account during the planning process. This paper presents an analysis of the available 3GPP QoS mechanisms in the different releases in order to include factors in RAN planning for QoS support. Finally, the differences in the RAN dimensioning between best effort and QoS support are exemplified.

The rapid evolution of Grid Computing and the development of new middleware services make Grid platforms increasingly used not only for best effort scientific jobs but also in industrial and business applications. This has taken to the growing demand of Quality of Service (QoS) support. However, the QoS issue on Grid is quite difficult, as Grid has been originally designed without any QoS support, and it is a complex system. During the previous years some solutions have been proposed to supply QoS for specific classes of applications. This results in a focused and a heterogeneous approach, so that it is hard to evaluate its sufficiency and its robustness with respect to the large spectrum of possible Grid applications. In this context, our contribution concerns three points: first, we analyze the current approach to QoS on Grid as a relationship among QoS features, applications, and architectures; second, we evaluate the QoS requirements of two recent QoS‐demanding applications on Grid, namely Massive Multiplayer Online Games and Urgent Computing, comparing these requirements with the support provided by current QoS architectures; and third, we propose an alternative approach to QoS provision on Grid based on the definition of a dedicated QoS‐management layer to overcome the limitations of the current methodologies. Copyright © 2010 John Wiley &amp; Sons, Ltd.

To meet the growing demand for broadband wireless connectivity, integrating 3G and IEEE 802.16 networks is a clear and viable solution. To the best of the authors' knowledge, this is the first solution proposed for the integration of 3G and 802.16 wireless networks. We present a novel network and mobile client architecture that provides seamless roaming and mobility while maintaining connectivity across these heterogeneous wireless networks and provides quality of service (QoS) support. To provide QoS support to the application in the integrated network environment, the proposed architecture incorporates the procedures for activating a QoS session, the translation between network-specific QoS classifications, and network and session layer QoS support. We provide simulation results that show the viability and performance of the proposed QoS architecture

The paper studies fair scheduling with quality of service (QoS) support in ad hoc networks. The goal is to satisfy the minimum bandwidth requirements of guaranteed flows and to provide a fair share of residual bandwidth among all flows. We propose a new cluster-based mechanism called two-tier slot allocation protocol (2TSAP), which improves system throughput and ensures per-cluster fairness while satisfying the requirements of guaranteed flows. With 2TSAP, the network is logically partitioned into clusters, each with a scheduler. The scheduler assigns time slots to mobiles in the affiliated clusters based on the first tier algorithm. The mobiles scheduled to send at the next time slot then in turn assign the time slot to flows determined by the second tier algorithm. We compare the performance of 2TSAP with Q EMLM-FQ, a virtual-time based fair scheduling mechanism with QoS support. The simulation results show that 2TSAP meets the minimum requirements of guaranteed flows, shares the residual bandwidth fairly among all flows, and improves overall system throughput.

In this letter, we address the problem of resource allocation with efficiency and quality of service (QoS) support in uplink for a wireless CDMA network supporting real-time (RT) and non-realtime (NRT) communication services. For RT and NRT users, there are different QoS requirements. We introduce and describe a new scheme, namely, traffic aided uplink opportunistic scheduling (TAUOS). While guaranteeing the different QoS requirements, TAUOS exploits the channel condition to improve system throughput. In TAUOS, the cross-layer information, file size information, is used to improve fairness for NRT users. Extensive simulation results show that our scheme can achieve high system throughput in uplink wireless CDMA systems, while guaranteeing QoS requirements.

Energy saving and quality of service (QoS) support are two important issues of Long-Term Evolution Advanced (LTE-A) wireless networks. Unfortunately, achieving high energy saving efficiency often implies degradation of QoS support. In this paper, we address the issue of QoS support under Discontinuous Reception (DRX), the power saving mechanism of LTE-A. Different from previous studies which analyzed average packet delay under DRX mechanism, we adopt packet loss ratio due to violation of delay bound as QoS requirements of real-time applications. The problem of QoS support under DRX mechanism is defined as an optimization problem to maximize average power saving under the constraint that the packet loss ratio is no greater than a pre-determined threshold. We derive packet loss ratio and energy saving efficiency given DRX parameter values and propose an approach to select appropriate DRX parameter values. Simulations are conducted to verify our analysis. We found that the analytical results match well with simulations. Moreover, the energy saving efficiency achieved by the selected DRX parameter values is very close to that of the optimum solution.

We propose a domain-specific service selection mechanism and system implementation to address the issue of runtime adaptation of composite services that implement mission-critical business processes. To this end, we leverage quality of service (QoS) as a means to specify rigid dependability requirements. QoS does not include only common attributes such as availability or response time but also attributes specific to certain business domains and processes. Therefore, we combine both domain-agnostic and domain-specific QoS attributes in an adaptive QoS model. For specifying the service selection strategy, we propose a domain-specific language called VieDASSL to specify so-called selectors. This language can be used to specify selector implementations based on the available QoS attributes. Both the QoS model implementation and the selectors can be adapted at runtime to deal with changing business and QoS requirements. Our approach is implemented on top of an existing WS-BPEL engine. We demonstrate its feasibility by implementing a case study from the telecommunication domain.

In this paper we introduce a novel MAC protocol that provides Quality of Service (QoS) support for multimedia traffic in UWB-based wireless local area networks. The proposed protocol allocates transmission opportunities to QoS and best effort traffic using a set of scheduling and resource control algorithms. The algorithms account for the UWB characteristics such as the co-existence of multiple simultaneous transmissions as well as the possibility of dynamically assigning the nodes' transmission rate and power. The simulation results show that the proposed protocol can provide QoS support while optimizing resource utilization.

The evolution of wireless sensor technology allows for the provision of enhanced services to miscellaneous application domains. In parallel, Quality of Service (QoS) support becomes necessary to satisfy the needs of these new service models. This paper presents QoS requirements from a service model perspective and describes challenges for QoS support in WSNs. We also provide a review of current efforts in Medium Access Control (MAC) QoS support in WSNs. Then, we investigate various performance metrics of IEEE 802.15.4 standard in order to determine the technological issues that arise. From the outcome of the experiments conducted, using ns-2, we identified that different schemes of services and application scenarios for different ways of deployment, scales of network and traffic load can satisfy diverse user needs and requirements.

Web service composition (WSC) is the task of combining a chain of connected single services together to create a more complex and value-added composite service. Quality of service (QoS) has been mostly applied to represent nonfunctional properties of web services and differentiate those with the same functionality. Many research has been done on QoS-aware service composition, as it significantly affects the quality of a composite service. However, existing methods are restricted to predefined workflows, which can incur a couple of limitations, including the lack of guarantee for the optimality on overall QoS and for the completeness of finding a composite service solution. In this paper, instead of predefining a workflow model for service composition, we propose a novel planning-based approach that can automatically convert a QoS-aware composition task to a planning problem with temporal and numerical features. Furthermore, we use state-of-the-art planners, including an existing one and a self-developed one, to handle complex temporal planning problems with logical reasoning and numerical optimization. Our approach can find a composite service graph with the optimal overall QoS value while satisfying multiple global QoS constraints. We implement a prototype system and conduct extensive experiments on large web service repositories. The experimental results show that our proposed approach largely outperforms existing ones in terms of solution quality and is efficient enough for practical deployment.