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1.
一种基于OSPF扩展的预计算QoS路由算法研究 总被引:2,自引:0,他引:2
在一个MPLS域,LSPs的建立需要QoS路由协议分发QoS相关的信息和执行QoS路径选择,但是传统的OSPF不支持QoS路由。本文提出并详细讨论了一种0SPF-QoSR路由机制,它是对OSPF路由协议的扩展,基于网络的动态可用带宽资源和流的QoS请求来决定流的QoS LSPs。仿真证明,该机制在丢包率、链路利用率、延时方面的性能优于只考虑最短路径的OSPF。 相似文献
2.
A fuzzy queue-aware routing approach for wireless mesh networks 总被引:1,自引:0,他引:1
Billy Pinheiro Vagner Nascimento Rafael Lopes Eduardo Cerqueira Antonio Abelem 《Multimedia Tools and Applications》2012,61(3):747-768
Recent advances in Wireless Mesh Networks (WMNs) have overcome the drawbacks of traditional wired and ad-hoc networks and now they are seen as a means of allowing last mile communications with quality level assurance in Future Multimedia Systems. However, new routing schemes are needed to provide end-to-end Quality of Service (QoS) and Quality of Experience (QoE) support for delay/loss/jitter-sensitive multimedia applications. The well-known OLSR (Optimized Link State Routing) protocol with ETX (Expected Transmission Count) metric brings many benefits to the path selection process, but has a drawback with regard to queue availability management, which reduces the system performance. This problem is caused when OLSR-EXT control messages are exchanged and the queues of mesh routers along the end-to-end communication path are overloaded. As a result, multimedia-related packets will suffer from loss/delay/jitter and the overall system performance will decrease. This paper proposes the Optimized Link State Routing-Fuzzy ETX Queue (OLSR-FEQ) protocol to overcome the limitations of OLSR-ETX regarding queue availability, QoS and QoE assurance. OLSR-FEQ optimizes network and user-based parameters by coordinating queue availability, QoS and fuzzy issues in the routing decision process as a way of allocating the best paths for multimedia applications. Performance evaluations were carried out with the Network Simulator (NS-2.34) to show the benefits of the proposed solution when compared with existing routing schemes, namely OLSR-ETX, OLSR-FLC, OLSR-MD and HWMP (IEEE 802.11s standard), regarding QoS (unsuccessful packet delivery and throughput) and QoE (PSNR, SSIM, VQM and MOS) parameters. 相似文献
3.
The current standard for intra-domain network routing, Open Shortest
Path First (OSPF), suffers from a number of
problems-the tunable parameters (the weights) are hard to
optimize, the chosen paths are not robust under
changes in traffic or network state, and some network links are over-used
at the expense of others. We present prototypical scenarios that illustrate these problems.
Then we propose several variants of a protocol to eliminate or
alleviate them and demonstrate the improvements in performance under
those scenarios. We also prove that these protocols never perform
significantly worse than OSPF and show that for at least a limited
class of network topologies, it is possible to find efficiently the
optimal weight settings. Some of the problems with OSPF are well known; indeed, there are
several routing protocols that perform better than OSPF in routing
quality (i.e., in terms of congestion, delay, etc.). OSPF’s
popularity persists in part because of its efficiency with respect to
several resource bounds. In contrast, many competing protocols that
provide routing superior to OSPF are computationally prohibitive.
Motivated by this consideration, we designed our protocols not only to
achieve better routing quality than OSPF, but also to use resources in
amount comparable with OSPF with respect to offline broadcast
communication, size of and time to compute routing tables, packet delivery
latency, and packet header structure and size. 相似文献
4.
The increasing demand for real-time applications in Wireless Sensor Networks (WSNs) has made the Quality of Service (QoS) based communication protocols an interesting and hot research topic. Satisfying Quality of Service (QoS) requirements (e.g. bandwidth and delay constraints) for the different QoS based applications of WSNs raises significant challenges. More precisely, the networking protocols need to cope up with energy constraints, while providing precise QoS guarantee. Therefore, enabling QoS applications in sensor networks requires energy and QoS awareness in different layers of the protocol stack. In many of these applications (such as multimedia applications, or real-time and mission critical applications), the network traffic is mixed of delay sensitive and delay tolerant traffic. Hence, QoS routing becomes an important issue. In this paper, we propose an Energy Efficient and QoS aware multipath routing protocol (abbreviated shortly as EQSR) that maximizes the network lifetime through balancing energy consumption across multiple nodes, uses the concept of service differentiation to allow delay sensitive traffic to reach the sink node within an acceptable delay, reduces the end to end delay through spreading out the traffic across multiple paths, and increases the throughput through introducing data redundancy. EQSR uses the residual energy, node available buffer size, and Signal-to-Noise Ratio (SNR) to predict the best next hop through the paths construction phase. Based on the concept of service differentiation, EQSR protocol employs a queuing model to handle both real-time and non-real-time traffic. 相似文献
5.
提出一种流媒体视频点播服务(VOD服务)的新架构,在应用层上实现VOD服务所需数据的多传播路径,旨在降低网络带宽波动对流媒体VOD服务的影响,克服传统方式下当某一传输数据的路由因请求过多或其他原因发生拥塞时服务质量(QoS)难以保证的问题。还具体给出了多路径传播的协议和实现算法,实验结果也证明该架构能够有效减少对单一路由、特别是中心VOD服务器带宽的压力,使得数据传输能够根据带宽的变化动态变化,从而更好地保证VoD服务的QoS。 相似文献
6.
Multimedia applications such as video-conferencing, telemedicine, HDTV, etc. have very stringent quality-of-service (QoS) demands and require a connection-oriented service. For these applications, a path satisfying their requirements in terms of bandwidth, delay buffer, etc. needs to be found. As conventional IP routing is based only on hop counts, it is not suitable for multimedia applications. It is clear that, to route requests that have QoS requirements, existing routers should be made QoS aware and the packet forwarding should be based on QoS parameters. Also, routing protocols like OSPF and RIP must be extended suitably to facilitate QoS routing. The goal of QoS routing algorithms is to find a loop-less path satisfying a given set of constraints on parameters like bandwidth, delay, etc. The path selection process could return either the entire path to the destination or the best next hop for the request. The first case is called “source routing” and the second is referred to as “distributed routing”. In this paper, we propose a new distributed QoS routing algorithm for unicast flows, which has a very low call establishment overhead. Our algorithm makes use of existing IP routing protocols such as OSPF and RIP with minimal modifications 相似文献
7.
该文介绍了全分布式分组无线网络中路由算法。当前广泛运用的OSPF路由算法在网络的链路发生阻塞时,不能及时探测到链路状况。当链路发生拥塞时,在发包率继续增大的时候,只能简单地丢弃数据包。就此该文在分布式的无线网络中应用了蚂蚁算法。该算法由发送探测包来担任“觅食蚂蚁”在短时间内找出最优路径,分散流量,避免网络的拥塞。通过仿真结果表明:该算法在网络利用率和数据包传送时延上有较好的改善。 相似文献
8.
9.
探讨了基于多QoS约束的路由交换原型系统及其关键技术的设计和实现。通过分析传统路由交换体系中路由协议和交换机制的局限性,提出支持多QoS约束的QOSPF路由协议,并在此基础上结合多协议标记交换技术,实现了基于多QoS约束的路由交换原型系统,它能为数据流建立满足多QoS约束的标记交换路径,不仅满足了数据流的多QoS需求,并能提高分组交换效率。最后通过实验验证了原型系统的有效性和可行性。 相似文献
10.
The lack of an effective cooperation between the data, control and management plane of QoS routing solutions presented so far, prevents the implementation of service differentiation in the context of pure IP-based networks. Most of paths calculation proposals performed by the control plane are unaware of service characteristics of each flow. Scalable data plane QoS proposals ignore the issue about selecting the best paths to route the traffic. Proposed management plane schemes do not perform the network state maintenance and service level monitoring. Multi-service routing is a flow-based forwarding protocol that implements the service differentiation in pure IP-based networks, using a straight cooperation between data, control and management plane. This cooperation is accomplished by a data plane supporting the DiffServ model and performs route selection based on flows service class, which is exploited by the management plane to carry out the network state maintenance, and performance monitoring by using the RTCP protocol, to provide service metrics to control plane for route calculation. Simulation experiments show better performance results achieved by Multi-service routing compared to those obtained by traditional link state protocol with the DiffServ model and QoS routing in heavy loaded network scenarios of mixed traffic having different service requirements. 相似文献
11.
OSPF协议测试中网络拓扑建模及其算法研究 总被引:1,自引:0,他引:1
OSPF协议是一种广泛使用的内部网关路由协议,文中提出了一种用于OSPF协议测试的网络拓扑建模方法以及相关算法。首先从实际网络中抽取出其中的网络拓扑模型,并将OSPF网络定义为一个有向加权图。之后在这个抽象网络拓扑模型的基础上,提出了一种最短路径树生成算法,并利用该算法实现了路由信息和路由表的生成。文中的模型与算法很好地体现了OSPF协议分层的特点,是构造测试内容的一种有效方法。 相似文献
12.
6LoWPAN标准将下一代互联网协议IPv6与IEEE 802.15.4标准联系起来,使得在低速无线个人区域网络(LoWPAN)上进行基于IPv6的数据传输成为可能。HiLow作为一种基于Mesh-under原理的分层路由方式,大大减少了控制报文的数量及存储空间的需求。通过对HiLow的父节点选择策略及路由恢复策略进行改进,增强了6LoWPAN网络的稳定性及路由的可靠性。最后在NS2中通过仿真实验对所做改进进行了验证,结果显示当存在失效节点时改进后的协议仍能保持较高的转发成功率。 相似文献
13.
While MPEG is the de facto encoding standard for video services, online video streaming service is becoming popular over the open network such as the
Internet. As the performance of open network is non-predictable and uncontrollable, the tuning of the quality of service (QoS)
for on-line video streaming services is difficult. In order to provide better QoS for the delivery of videos, there are proposals
of new encoding formats or new transmission protocols for on-line video streaming. However, these results are not compatible
with popular video players or network protocols and hence these approaches are so far not very successful. We use another
approach which tries to by-pass these problems. We designed a QoS Tuning Scheme and a QoS-Enabled Transmission Scheme for
transmitting MPEG videos from video servers to clients. According to the traffic characteristics between the video server
and each individual client, the QoS Tuning Scheme tunes the QoS to be delivered to each individual client on the fly. Furthermore,
our QoS-Enabled Transmission Scheme can be applied over any protocol, such as HTTP which is the most popular protocol over
the open network. With our transmission scheme, bandwidth can be better utilized by reducing transmitted frames which would
have missed their deadlines and would eventually be discarded by the clients. This is achieved by sending frames according
to their impact on the QoS in the playback under the allowed throughput. With these schemes, users can enjoy video streaming
through their favorite video players and with the best possible QoS. In order to facilitate the real time QoS tuning, a metric,
QoS-GFS, is developed. This QoS-GFS is extended from the QoS-Index, another metric which has taken human perspective in the
measurement of video quality. Hence QoS-GFS is better than the common metrics which measures QoS by means of rate of transmission
of bytes or MPEG frames. We designed and implemented a middleware to perform empirical tests of the proposed transmission
scheme and QoS tuning scheme. Experiment results show that our schemes can effectively enhance the QoS for online MPEG video
streaming services.
The work reported in this paper was supported in part by the RGC Earmarked Research Grant under RGC HKBU 2074/01E, and by
the FRG under FRG 00-01/I.
Joseph Kee-Yin Ng received a B.Sc. in Mathematics and Computer Science, a M.Sc. in Computer Science, and a Ph.D. in Computer Science from the
University of Illinois at Urbana-Champaign in the years 1986, 1988, and 1993, respectively. Dr. Ng is currently an associate
professor in the Department of Computer Science at Hong Kong Baptist University.
His current research interests includes Real-Time Networks, Multimedia Communications, Ubiquitous/Pervasive Computing, Mobile
and Location-aware Computing, Performance Evaluation, Parallel and Distributed Computing. Dr. Ng is the Technical Program
Chair for TENCON 2006, General Chair for The 11th International Conference on Embedded and Real-Time Computing Systems and
Applications (RTCSA 2005), Program Vice Chair for The 11th International Conference on Parallel and Distributed Systems (ICPADS
2005), Program Area-Chair for The 18th & 19th International Conference on Advanced Information Networking and Applications
(AINA 2004 & AINA 2005) and he had served as the General Co-Chair for The International Computer Congress 1999 & 2001 (ICC'99
& ICC'01), the Program Co-Chair for The Sixth International Conference on Real-Time Computing Systems and Applications (RTCSA'99)
and the General Co-Chair for The 1999 and 2001 International Computer Science Conference (ICSC'99 & ICSC'01).
Dr. Ng is a member of the Editorial Board of Journal of Pervasive Computing and Communications, Associate Editor of Real-Time
Systems Journal and Journal of Mobile Multimedia. He is a guest editor of International Journal of Wireless and Mobile Computing
for a special issue on Applications, Services, and Infrastructures for Wireless and Mobile Computing.
Dr. Ng is currently the Region 10 Coordinator for the Chapter Activities Board of the IEEE Computer Society, and is the Coordinator
of the IEEE Computer Society Distinguished Visitors Program (Asia/Pacific). He is a senior member of the IEEE and has been
a member of the IEEE Computer Society since 1991. Dr. Ng has been an exco-member (1993–95), General Secretary (1995–1997),
Vice-Chair (1997–1999), Chair (1999–2001) and is the immediate past Chairman of the IEEE, Hong Kong Section, Computer Chapter.
Dr. Ng received the Certificate of Appreciation for Leadership and Service (2000–2001) from IEEE Region 10 and the IEEE Meritorious
Service Award from IEEE Computer Society at 2004. He is also a member of the IEEE Communication Society, and ACM.
Karl R.P.H. Leung received his Ph.D. from The University of Hong Kong. He is currently a Principal Lecturer in the Department of Information
and Communications Technology at the Hong Kong Institute of Vocational Education (IVE). He is the founder of the Compuware
Software Testing Laboratory in the IVE with a donation from the Compuware Asia Pacific Co. Ltd. His research areas include:
domain modeling, mission critical software engineering methodology, secure workflow systems, GSM-based location estimation,
and QoS of MPEG streaming. He is a Senior Member of the IEEE and IEEE Computer Society, and has held major office of the IEEE
Hong Kong Section Computer Chapter. While he was the chairman in 1998, the Chapter won the IEEE Most Outstanding Computer
Society Chapter Award. He is also a Chartered Engineer of Engineering Council (UK), a Chartered Information Systems Engineer
of British Computer Society (UK), an Engineer of Hong Kong Institution of Engineers, Registered Professional Engineer (Information)
of Hong Kong Engineers Registration Board, and a member of ACM, BCS, ACS, HKIE and HKCS.
Calvin Kin Cheung Hui received a B.Sc. (First Class Honours) in Computer Science, and a M.Phil. degree in Computer Science from Hong Kong Baptist
University in the years 1999, and 2002, respectively. Mr. Hui's research interests includes Real-Time Networks, VoD Systems,
Video Streaming, Multimedia Communication, and Distributed Systems Performance Evaluation. 相似文献
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16.
This is a review of a video consisting of clips from presentations made at the Second IEEE International Conference on Fuzzy Systems (1993) and the 1993 IEEE International Conference on Neural Networks. Each video clip describes significant achievements and current advances in the fields of fuzzy logic and neural networks contributed by researchers from around the world. 相似文献
17.
蚁群算法的随机自适应性使得它很适合应用于无线传感器网络( WSN)环境中,所以本文针对WSN中的数据拥塞、传输延迟、能量消耗等问题,提出了一种基于蚁群算法的QoS路由协议.协议将如何搜索最佳路径问题抽象为组合规划问题,根据最小费用流规则定义了高带宽和低时延路径的判决条件,利用蚁群优化算法,寻找到不同目标函数的路径,达到... 相似文献
18.
随着互联网的快速发展,稳定可靠的路由协议变得越来越重要。OSPF协议作为中型网络最常用的路由协议。文章对互操作性测试的关键问题例如协议形式化建模及协议的不确定性进行了深入的分析。采用扩展Petri网对OSPF协议进行建模,并依此模型分析了OSPF协议的互操作性测试中存在的不确定性。同时,依据Petri网模型和MSC消息序列图,给出了交互模型的生成算法,最后为全文总结及未来的研究工作。 相似文献
19.
基于QoS路由及保障路由实施是支持MANET应用的关键.为解决MANET中QoS问题,在移动预测机制下提出了一种基于QoS保障的组播协议.该协议通过簇头选举,移动预测和QoS控制策略在组播源与含目的节点的组播簇头间确定最稳传输路径,并采用基于动态资源管理的QoS路由模型来保障路由实施.仿真结果显示该方案可获得较高传输成功率和较低控制开销,能有效支持MANET中具有QoS需求的组播传输. 相似文献
20.
In wireless sensor networks, most routing protocols consider energy savings as the main objective and assume data traffic with unconstrained delivery requirements to be a given. However, the introduction of video and imaging sensors unveils additional challenges. The transmission of video and imaging data requires both energy efficiency and QoS assurance (end-to-end delay and packet loss requirements), in order to ensure the efficient use of sensor resources as well as the integrity of the information collected. This paper presents a QoS routing model for Wireless Multimedia Sensor Networks (WMSN). Moreover, based on the traditional ant-based algorithm, an ant-based multi-QoS routing metric (AntSensNet) is proposed. The AntSensNet protocol builds a hierarchical structure on the network before choosing suitable paths to meet various QoS requirements from different kinds of traffic, thus maximizing network utilization, while improving its performance. In addition, AntSensNet is able to use a efficient multi-path video packet scheduling in order to get minimum video distortion transmission. Finally, extensive simulations are conducted to assess the effectiveness of this novel solution and a detailed discussion regarding the effects of different system parameters is provided. Compared to typical routing algorithms in sensor networks and the traditional ant-based algorithm, this new algorithm has better convergence and provides significantly better QoS for multiple types of services in wireless multimedia sensor networks. 相似文献