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基于数字证书的树型结构安全多播方案 总被引:1,自引:0,他引:1
该文提出一种基于数字证书的安全多播方案,采用树型的多播拓扑结构。多播树中的每个节点都有一个标识其身份的数字证书,除了成员身份认证外,还可以安全地分发会话密钥和实现会话数据的认证,因而减少了多播群密钥管理的复杂度;由于采用分层的树型多播结构,成员加入和退出有了更大的可扩展性。 相似文献
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容迟容断网络的移动性、间歇连通性和动态拓扑等动态特性使得当前应用于静态网络拓扑和固定多播容量的静态随机网络编码难以适应DTN网络环境的网络编码传输,为此提出了一种DTN网络环境下动态随机网络编码传输方法。该方法以马尔科夫信道模型为基础,根据节点的数据状态动态监测信道速率,在信源节点构造了带信道容量的网络流图,并计算和预测当前网络多播容量,最后根据多播容量的变化动态扩展和裁剪随机网络编码方案,实现DTN网络环境下数据的动态网络编码传输。仿真结果表明,相比传统的固定多播率编码方法,动态随机网络编码方法降低了数据的平均传递延迟,提高了数据投递率。 相似文献
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研究了多播路由协议及多播源分发数据报文的机制,提出一种新型的基于主动网络层次的多播体系结构,在自治系统AS中的分枝节点,亦可以根据该策略,构造以分枝节点为根的动态管理方式,从而可以动态地构造层次多播体系结构,在动态层次多播路由的具体实现中引入了agent和主动网络的概念,从而可以动态的加载多播路由,使得网络体系结构灵活与可编程. 相似文献
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传统网络采用调度前复制和扇出拷贝方式的多播交换模型不具备大规模可扩展能力。面向可重构基础网络,提出了一种部分扇出多播交换模型,该模型采用2×2布尔单元和布尔群组集线器建立基本交换结构,采用部分扇出拷贝方式和四状态分割编码实现自路由路径选择,进而推导了该模型在单多播混合业务源输入下的单播阻塞率、多播阻塞率和多播扇出率迭代过程。仿真实验表明:该模型在Bernoulli均匀业务源条件下,单播归一化负载强度为0.2时,多播阻塞率在10 10~10 2之间,多播时延总小于百纳秒量级上限,能够为到达业务提供时延上限保障。 相似文献
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综述了现存差错控制机制在处理大规模多播业务时的优缺点,并针对仍然存在的问题提出了一种新的适应于大规模多播业务的差错控制机制。除了具有良好的局部恢复性能外,本机制较好地实现了与现有IP模型的融合,降低了恢复时延,减少了重复恢复现象的发生,适应群组成员和拓扑结构的动态变化。 相似文献
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提出HMRB(Hierarchical Rings Based)协议,并对其性能进行仿真评估.HMRB建立在层次多环拓扑之上,是-可扩展的应用层多播协议.该方案设计提出区间划分机制.通过该机制可以简单快速地建立起转发树转发数据.利用p2psim,对HMRB进行性能仿真并和NICE协议作比较.仿真结果表明:和NICE相比,HMRB带宽利用率高、平均路径长度小、链路压力低. 相似文献
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Amr Alasaad Hasen Nicanfar Sathish Gopalakrishnan Victor C. M. Leung 《Wireless Networks》2013,19(7):1627-1651
Wireless mesh networking (WMN) is an emerging technology for future broadband wireless access. The proliferation of the mobile computing devices that are equipped with cameras and ad hoc communication mode creates the possibility of exchanging real-time data between mobile users in wireless mesh networks. In this paper, we argue for a ring-based multicast routing topology with support from infrastructure nodes for group communications in WMNs. We study the performance of multicast communication over a ring routing topology when 802.11 with RTS/CTS scheme is used at the MAC layer to enable reliable multicast services in WMNs. We propose an algorithm to enhance the IP multicast routing on the ring topology. We show that when mesh routers on a ring topology support group communications by employing our proposed algorithms, a significant performance enhancement is realized. We analytically compute the end-to-end delay on a ring multicast routing topology. Our results show that the end-to-end delay is reduced about 33 %, and the capacity of multicast network (i.e., maximum group size that the ring can serve with QoS guarantees) is increased about 50 % as compared to conventional schemes. We also use our analytical results to develop heuristic algorithms for constructing an efficient ring-based multicast routing topology with QoS guarantees. The proposed algorithms take into account all possible traffic interference when constructing the multicast ring topology. Thus, the constructed ring topology provides QoS guarantees for the multicast traffic and minimizes the cost of group communications in WMNs. 相似文献
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The stationary nature of nodes in a mesh network has shifted the main design goal of routing protocols from maintaining connectivity between source and destination nodes to finding high-throughput paths between them. Numerous link-quality-based routing metrics have been proposed for choosing high-throughput routing paths in recent years. In this paper, we study routing metrics for high-throughput tree or mesh construction in multicast protocols. We show that there is a fundamental difference between unicast and multicast routing in how data packets are transmitted at the link layer, and accordingly how the routing metrics for unicast routing should be adapted for high-throughput multicast routing. We propose a low-overhead adaptive online algorithm to incorporate link-quality metrics to a representative multicast routing protocol. We then study the performance improvement achieved by using different link-quality-based routing metrics via extensive simulation and experiments on a mesh-network testbed, using ODMRP as a representative multicast protocol.Our extensive simulation studies show that: (1) ODMRP equipped with any of the link-quality-based routing metrics can achieve higher throughput than the original ODMRP. In particular, under a tree topology, on average, ODMRP enhanced with link-quality routing metrics achieve up to 34% higher throughput than the original ODMRP under low multicast sending rate; (2) the improvement reduces to 21% under high multicast sending rate due to higher interference experienced by the data packets from the probe packets; (3) heavily penalizing lossy links is an effective way in the link-quality metric design to avoid low-throughput paths; and (4) the path redundancy from a mesh data dissemination topology in mesh-based multicast protocols provides another degree of robustness to link characteristics and reduces the additional throughput gain achieved by using link-quality-based routing metrics. Finally, our experiments on an eight-node testbed show that on average, ODMRP using SPP and PP achieves 14% and 17% higher throughput over ODMRP, respectively, validating the simulation results. 相似文献
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组播协议由于能够有效的利用网络带宽并降低服务器的负担因而受到广泛的关注.其中的共享树组播协议由于具有良好的扩展性而得到更多的支持,然而目前的共享树组播协议在动态移动环境中的性能很差,一些改进协议(单核移动协议)虽然可以很好的提高原有协议的性能但是所需要的额外开销很大.针对这种情况,本文提出了一种新的共享树组播协议-动态多核协议,该协议能够根据组播成员的分布动态的渐进的调整组播树的形状,从而能够在低开销的情况下为移动用户提供良好的性能.计算机仿真和数学分析都表明动态多核协议要明显优于共享树组播协议和单核移动协议. 相似文献
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Jianfeng Guan Huachun Zhou Changqiao Xu Hongke Zhang Hongbin Luo 《Wireless Personal Communications》2011,61(4):657-677
Mobile multicast is based on the traditional multicast protocols and the mobility support protocols to provide the multicast services for the mobile subscribers. Several mobile multicast methods were proposed in the past few years, but most of them are based on Mobile IPv6 and its variants which require the mobile node to support the mobility function. Recently, Proxy Mobile IPv6 (PMIPv6) was proposed to provide the mobility support for the mobile node with or without mobility function, and the previous studies have shown that PMIPv6 can improve the performance in term of the handover performance and protocol cost. However, PMIPv6 mainly concerns on the mobility support for unicast routing and little considers the multicast routing. In this paper, we propose two multicast methods called the MAG (Mobile Access Gateway)-based method and LMA (Local Mobility Anchor)-based method based on the different multicast delivery transmission path to extend PMIPv6, and analyze their performance under the different scenarios. The analytical results show that the LMA-based method is suitable for the higher speed, bigger domain size, and larger network topology scenarios, whereas the MAG-based method is suitable for the lower speed, smaller domain size and smaller network topology scenarios. 相似文献
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In general topology networks, routing from one node to another over a tree embedded in the network is intuitively a good strategy, since it typically results in a route length of O(logn) links, n being the number of nodes in the network. Routing from one node to another over a ring embedded in the network results in route length of O(n) links. However, in group (many-to-many) multicast, the overall number of links traversed by each packet, i.e., the networks elements on which resources must possibly be reserved, is typically O(N) for both tree and ring embedding, where N is the size of the group. The paper focuses on tree versus ring embedding for real-time group multicast in which all packets should reach all the nodes in the group with a bounded end-to-end delay. Real-time properties are guaranteed by the deployment of time-driven priority in network nodes. In order to have a better understanding of the nontrivial problem of ring versus tree embedding, we consider static, dynamic and adaptive group multicast scenarios. Tree and ring embedding are compared using different metrics. The results are interesting and counterintuitive, showing that embedding a tree is not always the best strategy. In particular, dynamic and adaptive multicast on a tree require a protocol for updating state information during operation of the group. Such a protocol is not required on the ring where the circular topology and implicit token passing mechanisms are sufficient. Moreover, the bandwidth allocation on the ring for the three multicast scenarios is O(N), while on a general tree it is O(N) for the static multicast scenario and O(N/sup 2/) for the dynamic and adaptive multicast scenarios. 相似文献
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Pingyi Fan Chen Zhi Chen Wei Ben Letaief K. 《Selected Areas in Communications, IEEE Journal on》2009,27(5):749-762
We first consider a topology consisting of one source, two destinations and one relay. For such a topology, it is shown that a network coding based cooperative (NCBC) multicast scheme can achieve a diversity order of two. In this paper, we discuss and analyze NCBC in a systematic way as well as compare its performance with two other multicast protocols. The throughput, delay and queue length for each protocol are evaluated. In addition, we present an optimal scheme to maximize throughput subject to delay and queue length constraints. Numerical results will demonstrate that network coding can bring significant gains in terms of throughput. 相似文献
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Banerjee S. Seungjoon Lee Bhattacharjee B. Srinivasan A. 《Networking, IEEE/ACM Transactions on》2006,14(2):237-248
We introduce Probabilistic Resilient Multicast (PRM): a multicast data recovery scheme that improves data delivery ratios while maintaining low end-to-end latencies. PRM has both a proactive and a reactive components; in this paper we describe how PRM can be used to improve the performance of application-layer multicast protocols especially when there are high packet losses and host failures. Through detailed analysis in this paper, we show that this loss recovery technique has efficient scaling properties-the overheads at each overlay node asymptotically decrease to zero with increasing group sizes. As a detailed case study, we show how PRM can be applied to the NICE application-layer multicast protocol. We present detailed simulations of the PRM-enhanced NICE protocol for 10 000 node Internet-like topologies. Simulations show that PRM achieves a high delivery ratio (>97%) with a low latency bound (600 ms) for environments with high end-to-end network losses (1%-5%) and high topology change rates (5 changes per second) while incurring very low overheads (<5%). 相似文献
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To provide a multicasting service, several multicast protocols for mobile hosts (MHs) have been proposed. However, all of these protocols have faults, such as non‐optimal delivery routes and data loss when hosts move to another network, resulting in insecure multicast data transmissions. Thus, this paper presents a new reliable and efficient multicast routing protocol for mobile IP networks. The proposed protocol provides a reliable multicast transmission by compensating the data loss from the previous mobile agent when a MH moves to another network. In addition, an additional function allows for direct connection to the multicast tree according to the status of agents, thereby providing a more efficient and optimal multicast path. The performance of the proposed protocol is confirmed based on simulations under various conditions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献