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QoS online routing and MPLS multilevel protection: a survey 总被引:3,自引:0,他引:3
A survey of MPLS protection methods and their utilization in combination with online routing methods is presented in this article. Usually, fault management methods pre-establish backup paths to recover traffic after a failure. In addition, MPLS allows the creation of different backup types, and hence MPLS is a suitable method to support traffic-engineered networks. In this article, an introduction of several label switch path backup types and their pros and cons are pointed out. The creation of an LSP involves a routing phase, which should include QoS aspects. In a similar way, to achieve a reliable network the LSP backups must also be routed by a QoS routing method. When LSP creation requests arrive one by one (a dynamic network scenario), online routing methods are applied. The relationship between MPLS fault management and QoS online routing methods is unavoidable, in particular during the creation of LSP backups. Both aspects are discussed in this article. Several ideas on how these actual technologies could be applied together are presented and compared. 相似文献
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Real-time interactive multimedia multiparty communication is becoming a vital part of modern Internet services. As one of its applications, online gaming attracts a huge group of fans playing over the Internet. It has new requirements for relative QoS. This article gives a brief introduction to these new QoS requirements, and then presents an algorithm to satisfy these requirements in the differentiated services network for client-server-topology-based online gaming services. Our simulation results show that this algorithm can provide optimized relative QoS support for online gaming as an example of multiparty communications. 相似文献
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Present-day Internet protocol routers typically employ monolithic operating systems that are not easily upgradable and extensible. With the rapid rate of protocol development it is becoming increasingly important to dynamically upgrade router software in an incremental fashion. We have designed and implemented a high-performance, modular, extended services router software architecture in the Net BSD operating system kernel. This architecture allows code modules, called plugins, to be dynamically added and configured at run time. One of the novel features of our design is the ability to bind different plugins to individual flows; this allows for distinct plugin implementations to seamlessly coexist in the same runtime environment. We achieve high performance through a carefully designed modular architecture, an innovative packet classification algorithm that is highly efficient, and by caching that exploits the flow-like characteristics of Internet traffic. Compared to a monolithic best effort kernel, our implementation requires an average increase in packet processing overhead of only 8%, or 600 cycles per packet when running on an Intel Pentium Pro at 233 MHz. By shortcutting the forward loop based on the per-flow state we establish, we can forward packets up to three times faster than the best effort kernel 相似文献
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Sungwook Kim 《International Journal of Communication Systems》2009,22(4):469-482
Energy consumption has become an increasingly important consideration in many real‐time systems. Therefore, the design and analysis for energy‐efficient processor management techniques is an important and widely open research field. In this paper, I propose new online processor management algorithms to control heterogeneous multimedia services while maximizing energy efficiency. These online management algorithms—quality of service control, service request admission and scheduling algorithms—are combined in an integrated framework for higher system performance and energy efficiency. The most important feature of my proposed online framework is its adaptability, flexibility, and responsiveness to current system conditions. Simulation results clearly indicate the superior performance of my proposed framework to strike the appropriate performance balance between contradictory requirements. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Provisioning multimedia wireless networks for better QoS: RRM strategies for 3G W-CDMA 总被引:9,自引:0,他引:9
Sallent O. Perez-Romero J. Agusti R. Casadevall F. 《Communications Magazine, IEEE》2003,41(2):100-106
Third-generation mobile communication systems will bring a wide range of new services with different quality of service requirements and will open the ability to exploit radio resource management functions to guarantee a certain target QoS, to maintain the planned coverage area and to offer a high-capacity while using the radio resources in an efficient way. RRM functions impact the overall system efficiency and the operator infrastructure cost, so they will definitively play an important role in a mature 3G scenario. In order to provide some insight into radio resource management (RRM) strategies implementation, a range of representative case-studies with several innovative algorithms are presented and supported by simulation results in a realistic UMTS Terrestrial Radio Access Network scenario as devised in the 3GGP standardization forum. In particular, a decentralized uplink transmission rate selection algorithm in the short term, a congestion control mechanism to cope with overload situations, and downlink scheduling for layered streaming video packets are proposed. 相似文献
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With the evolution of QoS-capable 3G wireless networks, the wireless community has been increasingly looking for a framework that can provide effective network-independent end-to-end QoS control. In this article we first construct such a framework and then describe how dynamic SLA-based control can be used to achieve end-to-end QoS in a wired and wireless (UMTS) environment. The proposed framework, which is an extension to the IST CADENUS project, offers effective wired-wireless QoS translation, efficient QoS control and management, and dynamic SLA policy-based QoS provisioning. 相似文献
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Increasing highway traffic congestion and real estate costs that limit the building of new highways has brought about a renewed interest in an automated highway system (AHS) where the vehicle steering task (“lateral control”) and the braking/throttle tasks (“longitudinal control”) are taken over by computers to increase the throughput of existing highways. Since safety plays a key role in the development of an AHS, fault-tolerant control is vital. In this paper, we develop a robust longitudinal sliding-mode control algorithm and prove that this control algorithm is stable for a certain class of faults. In addition, we show that intervehicle spacing errors will not become amplified along the AHS in the event of a loss of lead vehicle information. The performance of the sliding-mode controller is demonstrated through a series of simulations incorporating various vehicle and AHS faults 相似文献
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Gearshift control for automated manual transmissions 总被引:1,自引:0,他引:1
A gearshift control strategy for modern automated manual transmissions (AMTs) with dry clutches is proposed. The controller is designed through a hierarchical approach by discriminating among five different AMT operating phases: engaged, slipping-opening, synchronization, go-to-slipping, and slipping-closing. The control schemes consist of decoupled and cascaded feedback loops based on measurements of engine speed, clutch speed, and throwout bearing position, and on estimation of the transmitted torque. Models of driveline, dry clutch, and controlled actuator are estimated on experimental data of a medium size gasoline car and used to check through simulations the effectiveness of the proposed controller. 相似文献
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一种基于分层结构的动态自适应QoS分布控制模型 总被引:4,自引:0,他引:4
针对目前IP网实施QoS控制的主要难点问题,本文提出了基于分层结构的动态自适应QoS分布控制模型。本模型借鉴了DiffServ模型中基于端结点的分布控制思想,采用动态自适应的流控机制,这使得本模型不仅具有可扩展性,而且对网络的动态性与异构性具有适应能力。此外,本模型还采用分层结构将基于网络技术、视频编码技术以及FEC容错技术QoS控制策略进行有机集成,在带宽受限的情况下能为媒体流传输提供较好的服务质量。本模型已成功地应用于多媒体同步实时授课系统RealClass中。 相似文献
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徐海高 《电信工程技术与标准化》2011,24(6):62-65
本文分析了IP网络QoS(Quality of Service)管理中的资源管理机制,并在此基础上提出了基于网络状态监测的反馈控制方法和3个反馈环路.通过对网络历史状态信息的采集分析,定期重新分配瓶颈链路的带宽和各链路流量类的带宽,可以提高业务的接纳率和网络的业务容量.该方法实现在一个基于CORBA的原型系统中. 相似文献
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Dae-Hee Kim Danlu Zhang Naga Bhushan Rajesh Pankaj Seong-Jun Oh 《Wireless Networks》2013,19(2):131-144
This paper proposes an admission control algorithm for cellular networks based on the direct and dynamic monitoring of quality of services (QoS) performance metrics—both system delay tail and residual throughput. The main purpose of directly monitoring these QoS performance metrics is to more precisely meet the QoS requirements. The delay tail is efficiently estimated by the proposed algorithm and the total residual throughput is determined based on the total achieved throughput and total required throughput. With the estimated delay tails and measured residual throughput, the admission or rejection of a new user is determined at each base station. By doing so, the admission control algorithm improves resource utilization by guaranteeing the QoS. Additionally, the cellular system becomes more robust against the time-varying fading channel environment. The simulation results of the long term evolution downlink system show that the proposed algorithm can achieve a significant improvement in results compared to those of reference schemes. A general Neyman–Pearson-like framework is also used in evaluating the various admission control mechanisms. 相似文献
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Admission control for statistical QoS: theory and practice 总被引:3,自引:0,他引:3
In networks that support quality of service, an admission control algorithm determines whether or not a new traffic flow can be admitted to the network such that all users will receive their required performance. Such an algorithm is a key component of future multiservice networks because it determines the extent to which network resources are utilized and whether the promised QoS parameters are actually delivered. The goals in this article are threefold. First, we describe and classify a broad set of proposed admission control algorithms. Second, we evaluate the accuracy of these algorithms via experiments using both on-off sources and long traces of compressed video; we compare the admissible regions and QoS parameters predicted by our implementations of the algorithms with those obtained from trace-driven simulations. Finally, we identify the key aspects of an admission control algorithm necessary for achieving a high degree of accuracy and hence a high statistical multiplexing gain 相似文献
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