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Algorithm for Delay-Constrained Minimal Cost Group Multicasting 总被引：1，自引：0，他引：1
Group multicast routing algorithms satisfying quality of service requirements of real-time applications are essential for high-speed networks. A heuristic algorithm was presented for group multicast routing with bandwidth and delay constrained. A new metric was designed as a function of available bandwidth and delay of link, And source-specific routing trees for each member were generated in the algorithm by using the metric, which satisfy member＇s bandwidth and end-to-end delay requirements. Simulations over random network were carried out to compare the performance of the proposed algorithm with that from literature. Experimental results show that the algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover,the algorithm can avoid link blocking and enhance the network behavior efficiently. 相似文献
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保证服务质量的QoS路由（Quality of Service Routing）是网络中解决QoS问题的一项关键技术。QoS路由的主要目标是为接入的业务选择满足服务质量要求的传输路径,同时保证整个网络资源的有效利用。度量参数选择问题、寻路问题和路由信息不准确问题是QoS路由中的几个主要研究内容。多约束QoS路由算法通常是NPC问题,本文先对QoS路由中的问题进行分娄,再对当前研究的一些多约束QoS路由算法进行了归纳与分析。这些算法对于在Internet中实现QoS有着重要的指导意义。 相似文献
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随着移动自组织网络(MANET)的应用领域日益扩大,要求它必须提供一定的服务质量(QoS)保证,而QoS路由协议是MANET支持QoS的一个关键理论和技术,也是目前的一个研究热点。本文对当前自组织网络的QoS主要路由协议进行了详细的分析与研究,并从路由机制、单向链路的支持、多播功能、QoS参数选择以及节能几个方面进行了比较和分析;最后指出了今后的研究方向。 相似文献
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刘莞 《福建工程学院学报》2009,7(3)
提出一种新的基于代理的系统--应用层自适应多播AALM系统,改善网络的异构性和传输实时性.在局域范围内采用高效率的IP multicaat进行数据传输,每个多播域中设置一个代理服务器MAN,MAN之间的主干网络通过应用层多播进行数据传输,实现在Internet范围内的多点数据通信.采用了XML驱动的服务定制机制,可以满足不同应用需求,节省大量的网络资源,提供网络吞吐量,提高视频服务质量. 相似文献
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互联网络RCP(Ringed Crossed cube Petersen)拓扑结构被提出后并没有给出组播算法.本文利用RCP(n)网络的正则性、良好的可扩展性,以及比Qn,HP(n),RHP(n)网络直径更短和构造开销更小这些特性,按照构造组播树的方法,给出了RCP(n)网络的组播路由算法,并对该算法作了性能分析. 相似文献
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在分析IP over WDM光网络综合路由原理的基础上,提出了一种全新的基于QoS约束的IP over WDM网络综合路由算法.并通过与最短路径—首次命中标准算法进行仿真比较,证明该路由算法可以有效地降低总业务与QoS业务的阻塞率,更好地提供QoS服务保证. 相似文献
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In order to share multimedia transmissions in mesh networks and optimize the utilization of network resources, this paper presents a Two-stage Evolutionary Algorithm （TEA）, i.e., unicast routing evolution and multicast path composition, for dynamic multicast routing. The TEA uses a novel link-duplicate-degree encoding, which can encode a multicast path in the link-duplicate-degree and decode the path as a link vector easily. A dynamic algorithm for adding nodes to or removing nodes from a multicast group and a repairing algorithm are also covered in this paper. As the TEA is based on global evaluation, the quality of the multicast path remains stabilized without degradation when multicast members change over time. Therefore, it is not necessary to rearrange the multicast path during the life cycle of the multicast sessions. Simulation results show that the TEA is efficient and convergent. 相似文献
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Mobility and resource-limitedness pose challenging issues to service configuration for quality of service （QoS） management in ubiquitous computing environments. Previous configuration approaches, such as static resource reservation, dynamic resource allocation and single service composition are not valid in the environments. In this study, we present an adaptive service configuration approach. Firstly, we reduce the dynamic configuration process to a control model which aims to achieve the variation of critical QoS on minimal level with less resource cost. Secondly, to deal with different QoS variations, we design two configuration strategies--service chain reconfiguration and QoS parameter adjustment--and implement them based on fuzzy logic control theory. Finally, a configuration algorithm is developed to flexibly employ the two configuration strategies in tune with the error of critical QoS in configuration process. The results of simulation experiments suggest that our approach outperforms existing configuration approaches in both QoS improvement and resource utilization. 相似文献
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为了解决现有多播存在的问题,加速多播的应用,近年来提出了应用层多播(ALM)。根据ALM构建转发树的策略,可以将应用层多播分成集中式和分布式两类。由于ALM的开放性带来了一定的安全隐患,我们引入RBAC来解决该问题。该文基于集中式ALM的特点,提出了相应的RBAC模型—CALM-RBAC,并对该模型进行了UML语言的描述。 相似文献
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Multicasting is a communication service that allows an application to efficiently transmit copies of data packets to a set of destination nodes. The problem of finding a minimum cost multicast tree can be formulated as a minimum Steiner tree problem in networks, which is NP-completeness. MPH (minimum path cost heuristic) algorithm is a famous solution to this problem. In this paper,we present a novel solution TPMPH (two phase minimum path cost heuristic) to improve the MPH by generating the nodes and the edges of multicast tree separately. The cost of multicast tree generated by the proposed algorithm with the same time as MPH is no more than that of MPH in the worst case. Extensive simulation results show that TPMPH can effectively improve the performance on MPH, and performs better in large-scale networks and wireless networks. 相似文献
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探讨了波分多路网络 (WDM)中基于流量的多播路由问题 ,并建立了该问题与实际网络极其相近的模型 ,将该模型转化为最快路问题 ,利用最快路算法可在多项式时间内求解该问题 . 相似文献
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With the rapid growth of service scale, there are many services with the same functional properties but different non-functional
properties on the Internet. There have been some global optimizing service selection algorithms for service selection. However,
most of those approaches cannot fully reflect users’ preferences or are not fully suitable for large-scale services selection.
In this paper, an ant colony optimization (ACO) algorithm for the model of global optimizing service selection with various
quality of srevice (QoS) properties is employed, and a user-preference based large-scale service selection algorithm is proposed.
This algorithm aims at optimizing user-preferred QoS properties and selecting services that meet all user-defined QoS thresholds.
Experiment results prove that this algorithm is very efficient in this regard. 相似文献
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MOU Yu-jie CAO Jian ZHANG Shen-sheng ZHANG Jian-hong 《浙江大学学报(A卷英文版)》2006,7(4):483-492
INTRODUCTION Web service technologies are immerging as a powerful vehicle for organizations that participate in Web based dynamic collaborations. An organization can publish its business processes as Web services to the Internet for potential customers to discover and use them. Compared with traditional fixed inter-orga- nization collaboration relationship, the Web-based dynamic collaboration brings service providers more customers and more profits, and enables consumers to search in a w… 相似文献
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本文主要研究Internet区分服务体系提供服务质量保证问题,分析了端到端服务质量体系结构、纽播技术,以及区分服务中存在着一些问题,以此,结合网络编码技术,本文提了基于网络编码的最大流单源组播路由算法。 相似文献
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提出了基于mesh结构的低功率消耗率组播路由(LPDMR)协议算法. 采用计分机制选择组播群首,而群首之间以最低功率消耗率来选择路经,并以按需方式组播,群内使用表驱动路由协议.结果表明提出的LPDMR路由算法可以大大提高包到达率和网络吞吐量,特别是提高了网络生命周期. 相似文献
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WANG Yang ZHAN Yi-chun YU Shao-hua 《重庆大学学报(英文版)》2007,6(4):265-272
This paper investigates the routing among autonomous systems (ASs) with quality of service (QoS) requirements. To avoid the intractability of the problem, abstract QoS capability must be informed among ASs, because the routhing which constrained QoS has been proved to be nondeterministic polynomial-time (NP) hard even inside an AS. This paper employs the modified Dijkstra algorithm to compute the maximum bottleneck bandwidth inside an AS. This approach lays a basis for the AS-level switching capability on which interdomain advertisement can be performed. Furthermore, the paper models the aggregated traffic in backbone network with fractional Brownian motion (FBM), and by integrating along the time axis in short intervals, a good estimation of the distribution of queue length in the next short intervals can be obtained. The proposed advertisement mechanism can be easily implemented with the current interdomain routing protocols. Numerical study indicates that the presented scheme is effective and feasible. 相似文献
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YOUSEFI Saleh FATHY Mahmood BENSLIMANE Abderrahim 《浙江大学学报(A卷英文版)》2007,8(12):1990-2004
Currently, there is a growing belief that putting an IEEE 802.11-like radio into road vehicles can help the drivers to travel more safely. Message dissemination protocols are primordial for safety vehicular applications. There are two types of safety messages which may be exchanged between vehicles: alarm and beacon. In this paper we investigate the feasibility of deploying safety applications based on beacon message dissemination through extensive simulation study and pay special attention to the safety requirements. Vehicles are supposed to issue these messages periodically to announce to other vehicles their current situation and use received messages for preventing possible unsafe situations. We evaluate the performance of a single-hop dissemination protocol while taking into account the quality of service (QoS) metrics like delivery rate and delay. We realize that reliability is the main concern in beacon message dissemination. Thus, a new metric named effective range is defined which gives us more accurate facility for evaluating QoS in safety applications specifically. Then, in order to improve the performance, the effects of three parameters including vehicle's transmission range, message transmission's interval time and message payload size are studied. Due to special characteristics of the safety applications, we model the relationship between communication-level QoS and application-level QoS and evaluate them for different classes of safety applications. As a conclusion, the current technology of IEEE 802.11 MAC layer has still some challenges for automatic safety applications but it can provide acceptable QoS to driver assistance safety applications. 相似文献