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QoS Guarantees (qo + guarantee)
Selected AbstractsService based CAC with QoS guarantee in mobile wireless cellular networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2005Robert G. Fry Abstract The increasing variety and complexity of traffic in today's mobile wireless networks means that there are more restrictions placed on a network in order to guarantee the individual requirements of the different traffic types and users. Call admission control (CAC) plays a vital role in achieving this. In this paper, we propose a CAC scheme for multiple service systems where the predicted call usage of each service is used to make the admission decision. Our scheme enables real-time traffic to be transmitted using shared bandwidth without quality of service (QoS) requirements being exceeded. This ensures that the utilization of the available wireless bandwidth is maximized. Information about the channel usage of each service is used to estimate the capacity of the cell in terms of the number of users that can achieve a certain bit error rate (BER). Priorities assigned to each service are used to allocate the network capacity. An expression for the handoff dropping probability is derived, and the maximum acceptance rate for each service that results in the estimated dropping probability not exceeding its QoS requirements is calculated. Each call is then accepted with equal probability throughout the duration of a control period. Achieved QoS during the previous control period is used to update the new call acceptance rates thus ensuring the dropping probability remains below the specified threshold. Simulations conducted in a wideband CDMA environment with conversational, streaming, interactive and background sources show that the proposed CAC can successfully meet the hard restraint on the dropping probability and guarantee the required BER for multiple services. Copyright © 2005 John Wiley & Sons, Ltd. [source] QoS guarantee in telecommunication networks: technologies and solutionsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2004Enzo Fortunato Abstract The aim of this paper is to show the effect of the presence of specific management functions within a network that offers quality of service (QoS). The objective is not privileging a particular technology but to highlight the importance to know which control functions a solution may use, which performance limits the functions have and what can be a realistic user expectation. The paper focuses on the meaning of QoS and on the applications requiring quality, then describes QoS solutions including transport technologies, QoS-oriented technologies, parameters and management functions. In more detail, the effect on QoS provision of the following issues is investigated and discussed concerning the possibility (or not) to aggregate and differentiate traffic, the implementation of call admission control and of traffic filtering to limit flows to their committed rates. Again, the conclusions should not be considered a merit mark about technology, but only an investigation about: what users and customers should expect by the technologies using specific control functions evidencing that the real limitations are not imposed by a specific technology, whose features may be changed and extended, but by the application of control functions that can guarantee requirements' matching. Copyright © 2004 John Wiley & Sons, Ltd. [source] VoIP network architectures and QoS strategyBELL LABS TECHNICAL JOURNAL, Issue 4 2003Bharat T. Doshi Voice over IP (VoIP) has received much attention in recent years with the promise of lower costs, as well as new revenue-generating services. Cost and services advantages of carrying voice over IP compared to over the current circuit network are made possible by a common high-capacity packet infrastructure for voice, data, and multimedia services. An important requirement of such a packet infrastructure is the ability to provide public-switched telephone network (PSTN) grade quality without excessive over-provisioning. In this paper, we describe an approach to offer AbsoluteQoSÔ to voice and other demanding applications over a general-purpose packet network. AbsoluteQoS is defined as the ability to provide an engineered bound on call-blocking and quantitative QoS guarantee that calls-in-progress will receive. The proposed strategy is based on key innovations in architectures and protocols, as well as business models of PSTN and packet networks. © 2003 Lucent Technologies Inc. [source] QoS-aware fair packet scheduling in IEEE 802.16 wireless mesh networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6-7 2010Yajun Li Abstract In this paper, we address the problem of heterogeneous quality-of-service (QoS) provisioning in IEEE 802.16-based wireless mesh networks. Our objective is to provide a novel service differentiation scheme based on distributed scheduling in the IEEE 802.16-based mesh mode, thereby offering QoS guarantees. We first devise a novel scheme for the traffic class differentiation, which can be implemented at the medium access control layer. We then present a QoS-aware fair packet scheduling (QFPS) algorithm to fulfill the QoS provisioning. With QFPS, a traffic flow with urgent QoS demand is guaranteed to be given priority in wireless resource allocation over those ones with mild QoS requirements. A shorter end-to-end delay is therefore expected to be offered for the traffic flows with time-urgent requirements. Moreover, we propose a new fairness model among different traffic flows traversing the same node. All traffic flows passing through a node are served by the Deficit Round-Robin scheduling algorithm to achieve fairness within the same priority group. The experimental results of the QFPS demonstrate that various traffic flows are provided with a differentiated service that offers QoS guarantees. Copyright © 2009 John Wiley & Sons, Ltd. [source] Efficient scheduling discipline for Hierarchical Diff-EDFINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 3 2008Moutaz Saleh Packet networks are currently enabling the integration of traffic with a wide range of characteristics that extend from video traffic with stringent quality of service (QoS) requirements to the best-effort traffic requiring no guarantees. QoS guarantees can be provided in conventional packet networks by the use of proper packet-scheduling algorithms. As a computer revolution, many scheduling algorithms have been proposed to provide different schemes of QoS guarantees, with Earliest Deadline First (EDF) as the most popular one. With EDF scheduling, all flows receive the same miss rate regardless of their traffic characteristics and deadlines. This makes the standard EDF algorithm unsuitable for situations in which the different flows have different miss rate requirements since in order to meet all miss rate requirements it is necessary to limit admissions so as to satisfy the flow with the most stringent miss rate requirements. In this paper, we propose a new priority assignment scheduling algorithm, Hierarchal Diff-EDF (Differentiate Earliest Deadline First), which can meet the real-time needs of these applications while continuing to provide best-effort service to non-real time traffic. The Hierarchal Diff-EDF features a feedback control mechanism that detects overload conditions and modifies packet priority assignments accordingly. Copyright © 2007 John Wiley & Sons, Ltd. [source] QOS considerations for future military satcom networks with link layer dynamic resource allocationINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5 2006Aradhana Narula-Tam Abstract To efficiently utilize limited RF resources, future military packet-switched satellite networks will dynamically allocate resources on the uplink and downlink. Designing the resource allocation algorithms to maximize link layer efficiency is insufficient. The resource allocation algorithms must work cooperatively with the network layer and transport layer to optimize network layer performance and provide quality of service (QoS) to applications and users. Several mechanisms for facilitating this required cooperation between the layers are presented. The individual roles and actions of the layers as well as their interaction are defined. QoS schedulers that continue to provide service differentiation in the presence of link variations are illustrated. Downlink scheduling architectures that provide terminal QoS guarantees are demonstrated. Finally, the interaction between TCP and the dynamic resource allocation algorithms is investigated, leading to suggested modifications of either the resource allocation algorithms, the TCP protocol, or both. Copyright © 2006 John Wiley & Sons, Ltd. [source] Simulation analyses of weighted fair bandwidth-on-demand (WFBoD) process for broadband multimedia geostationary satellite systemsINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 4 2005Güray Açar Abstract Advanced resource management schemes are required for broadband multimedia satellite networks to provide efficient and fair resource allocation while delivering guaranteed quality of service (QoS) to a potentially very large number of users. Such resource management schemes must provide well-defined service segregation to the different traffic flows of the satellite network, and they must be integrated with some connection admission control (CAC) process at least for the flows requiring QoS guarantees. Weighted fair bandwidth-on-demand (WFBoD) is a resource management process for broadband multimedia geostationary (GEO) satellite systems that provides fair and efficient resource allocation coupled with a well-defined MAC-level QoS framework (compatible with ATM and IP QoS frameworks) and a multi-level service segregation to a large number of users with diverse characteristics. WFBoD is also integrated with the CAC process. In this paper, we analyse via extensive simulations the WFBoD process in a bent-pipe satellite network. Our results show that WFBoD can be used to provide guaranteed QoS for both non-real-time and real-time variable bit rate (VBR) flows. Our results also show how to choose the main parameters of the WFBoD process depending on the system parameters and on the traffic characteristics of the flows. Copyright © 2005 John Wiley & Sons, Ltd. [source] k -Splittable delay constrained routing problem: A branch-and-price approachNETWORKS: AN INTERNATIONAL JOURNAL, Issue 1 2010Jérôme Truffot Abstract Routing problems, which include a QoS-based path control, play a key role in broadband communication networks. We analyze here an algorithmic procedure based on branch-and-price algorithm and on the flow deviation method to solve a nonlinear k -splittable flow problem. The model can support end-to-end delay bounds on each path and we compare the behavior of the algorithm with and without these constraints. The trade-off between QoS guarantees and CPU time is clearly established and we show that minimizing the average delay on all arcs will yield solutions close to the optimal one at a significant computational saving. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010 [source] | |||||||||||||