共查询到20条相似文献,搜索用时 656 毫秒
1.
针对Ad Hoc网络中带QoS约束的多播路由问题,提出了一种新的结合MAODV多播路由发现方法和粒.子群优化算法的QoS多播路由发现算法。仿真试验显示该算法较好地改进了端到端传输的代价、延时和带宽利用率,能够找到一棵消耗趋于最小、状态稳定的多播路由树。 相似文献
2.
3.
4.
移动Ad Hoc网络是指由一组带有无线收发装置的移动节点组成的一个多跳的、不需要固定中心接入点或者基站支持的自治系统。对移动Ad Hoc网络多播路由中的MAODV协议进行理论分析,采用OPNET软件对该协议在AdHoc网络中的分组投递速率和延迟等关键参数进行仿真统计,并分析了节点移动速率对路由协议性能的影响。 相似文献
5.
6.
7.
传统的单目标路由协议很难完全满足Ad hoc网络业务量增加的需求.多目标路由协议在传输过程中可以构建最佳的多目标路由树,链路带宽消耗较小,节点的处理较少,分组交付时延较短,从而降低了通信开销.对Adhoc网络中的典型多目标路由协议MAODV和ODMRP协议进行性能分析,并用仿真工具NS2对它们进行仿真.仿真结果表明:多目标路由协议只有采用更加合理的算法和策略才能使其更稳定和更高效. 相似文献
8.
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
9.
10.
本文主要研讨了具有QoS约束的动态多播路由问题.文中描述了一种适用于QoS多播路由的网络模型,提出了一种动态QoS多播路由协议(DQMRP),该协议能操作在单播路由协议的顶层,它只要求网络链路(或节点)的局部状态信息,不需要维护全局状态信息.DQMRP可有效地减少构造一棵多播树的开销,多播组成员可动态地加入/退出多播会晤.该协议可搜索多条可行树枝,并能选择一条最优(或近优)树枝将新成员连接到多播树.文中给出了DQMRP的正确性证明和复杂性分析,并通过仿真实验验证了该协议的可用性和有效性. 相似文献
11.
The paper addresses the issue of minimizing the number of nodes involved in routing over a multicast tree and in the maintenance of such a tree in a datagram network. It presents a scheme where the tree routing and maintenance burden is laid only upon the source node and the destination nodes associated with the multicast tree. The main concept behind this scheme is to view each multicast tree as a collection of unicast paths and to locate only the multicast source and destination nodes on the junctions of their multicast tree. The paper shows that despite this restriction, the cost of the created multicast trees is not necessarily higher than the cost of the trees created by other algorithms that do not impose the restriction and therefore require all nodes along the data path of a tree to participate in routing over the tree and in the maintenance of the tree 相似文献
12.
I-Shyan Hwang San-Nan Lee Zen-Der Shyu Kang-Peng Chen 《Photonic Network Communications》2009,18(3):275-286
This paper proposes a novel dynamic core-based selection (DCS) algorithm for the multicast restoration in WDM mesh networks.
The core-based fault tolerance scheme provides a flexible way to control a number of core nodes with less control overheads
for searching the routing path, wavelength assignment (RWA), and restoration paths when fault occurs in the one-to-many multicast
domain. Compared with the source-based scheme, core-based schemes are easier to maintain, and specifically scalable in large-scale
topologies. In the core-based fault tolerance scheme, k-tuple domination nodes are selected to form a minimum sized vertex subset such that each vertex in the graph is dominated
by at least k vertices, where the k is defined as two in this paper. The proposed DCS algorithm is defined as each node in multicast tree session must be directly
connected to at least one core node in multicast tree session and also has to be directly connected to at least one core node
out of multicast tree session. The primary aim of this work is to provide the scalable and fast local survivability based
on the information from core nodes. Simulation results show that the proposed algorithm outperforms the Dual Tree and MRLR
algorithms in terms of total hop counts needed for all recovery paths and blocking probability for different network topologies. 相似文献
13.
针对无线网络中资源受限的组播路由问题,考虑网络节点的节点度限制和网络链路的带宽约束,以最小化组播路由开销为目标,提出了一种二进制编码方式的基于灰狼优化算法的组播路由策略.在给定的网络拓扑下,基于灰狼优化算法的组播路由策略可以迅速找到一棵包含源和目的节点的最小开销组播树.仿真结果表明,相比于遗传算法,所提出的基于灰狼优化算法的组播路由策略可以得到一棵开销更小的组播树,并且在相同的时间复杂下具有更强的算法稳定性. 相似文献
14.
Yu Quan Wu Kejun Luo Guoming Jin Yongxin 《电子科学学刊(英文版)》2007,24(3):412-416
A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR, multicast sessions are created and released only by source nodes. In each multicast session process, the source node keeps a list of intermediate nodes and destinations, which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing, the shortest virtual hierarchy routing tree is constructed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes, which are computed through the tree. No control packet is transmitted in the process of multicast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks. 相似文献
15.
In this work, we study dynamic provisioning of multicast sessions in a wavelength-routed sparse splitting capable WDM network
with an arbitrary mesh topology where the network consists of nodes with full, partial, or no wavelength conversion capabilities
and a node can be a tap-and-continue (TaC) node or a splitting and delivery (SaD) node. The objectives are to minimize the
network resources in terms of wavelength-links used by each session and to reduce the multicast session blocking probability.
The problem is to route the multicast session from each source to the members of every multicast session, and to assign an
appropriate wavelength to each link used by the session. We propose an efficient online algorithm for dynamic multicast session
provisioning. To evaluate the proposed algorithm, we apply the integer linear programming (ILP) optimization tool on a per
multicast session basis to solve off-line the optimal routing and wavelength assignment given a multicast session and the
current network topology as well as its residual network resource information. We formulate the per session multicast routing
and wavelength assignment problem as an ILP. With this ILP formulation, the multicast session blocking probability or success
probability can then be estimated based on solving a series of ILPs off-line. We have evaluated the effectiveness of the proposed
online algorithm via simulation in terms of session blocking probability and network resources used by a session. Simulation
results indicate that our proposed computationally efficient online algorithm performs well even when a fraction of the nodes
are SaD nodes. 相似文献
16.
Prompt and reliable communication between vehicular nodes are essential as its limited coverage and dynamic mobility rate introduces frequent change of network topology. The key feature of vehicular communication that establishes direct connectivity or Road Side Unit-based data transfer among vehicular nodes is responsible for sharing emergency information during critical situations. Multicast routing data dissemination among vehicular nodes is considered to be the potential method of parallel data transfer as they facilitate the option of determining an optimal multicast tree from feasible number of multicast trees established between the source and destinations. This estimation of optimal multicast tree using meta-heuristic techniques is confirmed to improve the throughput and reliability of the network when QoS-based constraints are imposed during multicast routing. An Improved Shuffled Frog-Leaping Algorithm-Based QoS Constrained Multicast Routing (ISFLABMR) is proposed for estimating an optimal multicast tree that confirms effective multi-constrained applied multicast routing between vehicular nodes. ISFLABMR minimizes the cost of transmission to 22% by reducing the number of multicast clusters formed during multicasting through the utilization of local and global-based optimizations. The simulation results of ISFLABMR proveits predominant reduction rate of 24% and 21% in average packet latency and energy consumptions incurred under multicast routing. 相似文献
17.
In this article we study the multicast routing problem in all-optical WDM networks under the spare light splitting constraint.
To implement a multicast session, several light-trees may have to be used due to the limited fanouts of network nodes. Although
many multicast routing algorithms have been proposed in order to reduce the total number of wavelength channels used (total
cost) for a multicast session, the maximum number of wavelengths required in one fiber link (link stress) and the end-to-end
delay are two parameters which are not always taken into consideration. It is known that the shortest path tree (SPT) results
in the optimal end-to-end delay, but it can not be employed directly for multicast routing in sparse light splitting WDM networks.
Hence, we propose a novel wavelength routing algorithm which tries to avoid the multicast incapable branching nodes (MIBs,
branching nodes without splitting capability) in the shortest-path-based multicast tree to diminish the link stress. Good
parts of the shortest-path-tree are retained by the algorithm to reduce the end-to-end delay. The algorithm consists of tree
steps: (1) a DijkstraPro algorithm with priority assignment and node adoption is introduced to produce a SPT with up to 38%
fewer MIB nodes in the NSF topology and 46% fewer MIB nodes in the USA Longhaul topology, (2) critical articulation and deepest
branch heuristics are used to process the MIB nodes, (3) a distance-based light-tree reconnection algorithm is proposed to
create the multicast light-trees. Extensive simulations demonstrate the algorithm’s efficiency in terms of link stress and
end-to-end delay. 相似文献
18.
19.
Performance assessment of multicast node placement for multicast routing in WDM networks with sparse light splitting 总被引:1,自引:0,他引:1
This article examines all-optical multicast routing for wavelength-routed optical networks with sparse Multicast Capable (MC)
nodes in two phases. The first phase is MC node placement and use of a simple and straightforward Maximum Path Count First
(MPCF) algorithm to obtain candidates for MC nodes. The second phase is multicast routing with MC-based schemes that minimizes
the number of wavelength channels with minimum transmission delay as required by a given multicast session, in that a light-tree
is first constructed to connect MC nodes in a multicast group by using two algorithms, namely, the Pre-computing Minimum Cost
(PMC) tree algorithm and the Pre-computing Shortest Path (PSP) tree algorithm. System performance of the proposed MPCF MC
node placement algorithm is compared with that of the Normalized Cuts (NC) MC node placement algorithm for both PMC and PSP
multicast routing. Furthermore, simulation results compare PMC and PSP multicast routing based on MPCF and NC node placement
with Re-route-to-Source (RTS), Re-route-to-Any (RTA), Member-First (MF), and Member-Only (MO) multicast routing based on a
light forest for a given multicast session in terms of average number of wavelengths needed, average blocking probability,
and mean maximum transmission delay.
相似文献
Tsung-Ching LinEmail: |
20.
The advances in wavelength-division multiplexing (WDM) technology are expected to facilitate bandwidth-intensive multicast
applications through light splitting. Due to complexity and cost constraints, light splitting (or optical multicast) nodes
are sparsely configured in a practical WDM network. In this article, we investigate the multicast routing problem under the
sparse light-splitting constraint. An efficient sparse splitting constrained multicast routing algorithm called Multicast
Capable Node First Heuristic (MCNFH) is proposed. The key idea of MCNFH is to include the shortest path, that includes most
of the multicast capable nodes, for configuring the multicast tree. Simulations and comparisons are used to demonstrate the
performance of MCNFH. Simulation results and analysis show that MCNFH builds multicast trees with the least wavelength channel
cost and with the smallest number of wavelengths used per link. In addition, MCNFH requires only one transmitter at the source
node. 相似文献