结合资源预留的分布式QoS组播路由算法

针对网络资源信息的动态变化对QoS组播路由算法的巨大影响,该文提出了一种与资源预留结合的分布式组播路由算法DQMTR。DQMTR通过在路径探索过程中进行资源预留克服网络信息变化对QoS路由算法的影响。DQMTR还通过记录预约资源的数量解决资源的过预约问题,并利用DiffServ体系下QoS路由算法的特点使算法能够适用于DiffServ网络。仿真实验表明,DQMTR提高了组成员加入的成功率,优化了平均路径代价值。     

基于QoS的动态组播路由算法

在分析了网络中基于QoS的组播路由问题的基础上,本文提出了一种新的动态算法,并进行了实验和分析,文中构造的路由方案成功地解决了当网络中存在多个组播及组播节点动态变化情况下的QoS路由选择问题,此方案不仅保证了带宽,端到端延时和延时抖动,优化了路由树的代价,而且有效地控制了算法的复杂性并可适用于大规模的网络中。     

基于蚁群算法的Ad Hoc网络QoS组播路由研究

在解决Ad Hoc网络QoS组播路由问题上,针对蚁群算法缺点,提出了一种融合粒子群优化思想的改进蚁群算法.该算法融合PSO思想以加速蚁群算法在路由发现及维护时的收敛速度.仿真结果表明,该算法具有较好的性能,是解决Ad Hoc网络QoS组播路由问题的有效方法.     

下一代网络中多约束路由算法述评

随着新业务的不断涌现,对网络QoS的需求也呈现出多样性,未来网络必然需要提供多约束的QoS路由能力.首先介绍了QoS路由及其路由策略和路由信息发布机制,并在对路由中特征值的选择和构成规则进行分析的基础上,着重讨论了当前多约束路由算法几种类型,分析了算法的性能和特点.最后,分析探讨多约束路由未来可能的研究方向.     

基于遗传算法优化的QoS组播路由算法

QoS组播路由技术作为网络多媒体信息传输的一种核心技术,下一代网络中的QoS组播路由的优化算法已经成为目前研究的一个热点。针对QoS组播的网络模型,提出一种适用于下一代网络的组播路由算法能够更好的满足下一代网络的QoS组播需求显得尤为重要。本文讨论了遗传算法优化的QoS组播路由算法,最后探讨了下一代网络QoS组播路由算法的研究方向。     

一种基于延时及带宽受限的启发式组播路由算法

在分析了网络中基于延时和带宽受限的组播路由优化问题的基础上,本文提出了一种新的启发式算法,并进行了实验和分析.结果表明文中构造的路由方案成功地解决了当网络中存在多组组播业务时的QoS路由选择问题.此方案不仅保证了带宽、端到端延时,优化了路由树的代价,而且有效地控制了算法的复杂性并可适用于大规模的网络中.     

基于自适应蚁群的多约束QoS组播路由算法

结合多约束QoS组播路由的特点,应用一种自适应蚁群优化算法解决组播路由问题.考虑到实际通信中链路利用率对网络的影响,将网络中链路的带宽转化为链路的代价问题,并在蚁群算法中根据蚂蚁所选路径的代价进行信息素更新,增加了信息素调整的自适应性,同时加快了算法的收敛速度,使得组播路由算法在考虑网络QoS约束的基础上进一步贴合实际网络的需求.     

基于遗传算法的QoS组播路由算法的改进

QoS组播路由技术在网络技术发展中占有很重要的地位,是一种关键的技术。在分析网络模型的基础上,建立了组播问题的数学模型。遗传算法是一种经典的寻优算法,应用广泛,提出了改进的算法。并且结合改进Dijkstra算法,使算法能很好地体现实际组播路由问题的特点。试验表明,这种新的算法可靠性更高,适应了当今网络性能优化的需要。     

一种基于蚁群优化的多媒体传感器网络 服务感知路由算法

本文针对多媒体传感器网络中三类基本服务:异常事件告警服务、信息查询服务以及流媒体查询服务,分析了不同服务的QoS需求,并抽象出多媒体传感器网络QoS路由模型.进而,利用改进的蚁群算法,设计了一个基于蚁群优化的服务感知路由算法ASAR (Ant-colony optimization based Service Aware Routing).本文设计服务感知的路由协议,旨在依据各类媒体数据包不同的QoS需求,选择相应的路由以合理利用全网资源、提高网络性能.最后,我们通过NS2仿真表明了较其他路由算法,本文提出的方法能够为多媒体传感器网络的多种服务提供更好的QoS保障,同时,比传统的蚁群算法具有更好的收敛性.     

下—代网络中多约束路由算法述评

随着新业务的不断涌现，对网络QoS的需求也呈现出多样性，未来网络必然需要提供多约束的QoS路由能力。首先介绍了QoS路由及其路由策略和路由信息发布机制，并在对路由中特征值的选择和构成规则进行分析的基础上，着重讨论了当前多约束路由算法几种类型，分析了算法的性能和特点。最后，分析探讨多约束路由未来可能的研究方向。     

多点并行蚁群搜索在多限制动态组播中的应用研究

随着Internet的快速发展和商用化的提高，多媒体组播通信越来越引起人们的广泛关注。以往的研究成果大多是集中在固定的多点模型上，而许多服务是无法应用这种应用模型的。本文在充分研究以往组播通信的基础上，针对没有固定组成员的动态组播通信提出了运用蚁群算法进行并行寻路的算法模型。同时，为了加快蚁群算法的收敛速度，对该算法进行了一定的改进。仿真试验表明，该算法是一种有效的适应动态组成员的组播路由算法，具有一定的实用价值。     

Multicast routing and its QoS extension: problems, algorithms, andprotocols

Multicast services have been increasingly used by various continuous media applications. The QoS requirements of these continuous media applications prompt the necessity for QoS-driven, constraint-based multicast routing. This article provides a comprehensive overview of existing multicast routing algorithms, protocols, and their QoS extension. In particular, we classify multicast routing problems according to their optimization functions and performance constraints, present basic routing algorithms in each problem class, and discuss their strengths and weaknesses. We also categorize existing multicast routing protocols, outline the issues and challenges in providing QoS in multicast routing, and point out possible future research directions     

A ring-based multicast routing topology with QoS support in wireless mesh networks

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.     

一种基于计算智能的组播路由算法

在通信网络中,多约束组播通信是提高网络运行效率和服务质量的重要途径。一些启发式的算法已经被用来解决多约束条件下的组播路由问题,如模拟退火算法,遗传算法,蚁群算法和粒子群优化算法等。然而,这些算法在求解多约束组播路由问题时存在收敛速度低和计算复杂度高的问题。萤火虫群优化(GSO)算法是一种近期在计算智能领域出现的卓越算法,它可以在一定程度上解决多约束组播树生成过程中收敛速度低和计算复杂度高的问题。提出了一种基于GSO的多约束组播树生成算法(GSO-MCM)。该算法可有效生成满足多约束要求的组播路由树。仿真结果表明提出的GSO-MCM算法在求解和收敛速度,以及网络规模适应性方面均有良好的性能。     

QoS-aware multicast routing for the Internet: the design andevaluation of QoSMIC

One of the main problems of the current Internet infrastructure is its inability to provide services at consistent quality-of-service (QoS) levels. At the same time, many emerging Internet applications, such as teleeducation, and teleconferencing, require multicast protocols that will provide the necessary QoS. In this paper, we propose QoSMIC, a multicast routing protocol for the Internet, that provides QoS-sensitive paths in a scalable, resource-efficient, and flexible way. QoSMIC differs from the previous protocols in that it identifies multiple paths and selects the one that can provide the required QoS. Two other key advantages of QoSMIC are its flexibility and adaptivity. First, the distribution tree does not have to be rooted at a preselected core router. Second, we can tradeoff between efficiency metrics depending on our needs; for example, we can tradeoff routing efficiency for a reduction in the control messages. Extensive simulations show that our protocol improves the resources utilization and the end-to-end performance compared to the current protocols. Specifically, our protocol reduces the call blocking probability by a factor of six and reduces the end-to-end delay by as much as 90% compared to the PIM protocol     

QoS Multicast Routing Based on Ant Algorithm in Internet

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A novel multicast traffic engineering technique in SDN using TLBO algorithm

In recent years, multicast communication is widely used by network providers to deliver multimedia contents. Quality of service (QoS) provisioning is one of the most important issues while transmitting multimedia contents using multicast. Traditional IP multicasting techniques suffer from reliability, scalability and have limitations to provide appropriate QoS for multimedia applications based on service level agreement (SLA). Nowadays, the advent of software defined networking (SDN), enables network providers to manage their networks dynamically and guarantee QoS parameters for customers based on SLA. SDN provides capabilities to monitor network resources and allows to dynamically configure desired multicasting policies. In this paper, we proposed a novel multicasting technique to guarantee QoS for multimedia applications over SDN. To deliver multimedia contents in an efficient manner, our proposed method models multicast routing as a delay constraint least cost (DCLC) problem. As DCLC problem is NP-Complete, we proposed an approximation algorithm using teaching–learning-based optimization to solve this problem. We evaluated our proposed method under different topologies. Experimental results confirmed that our proposed method outperforms IP multicast routing protocol, and it achieves a gain of about 25% for peak signal-to-noise ratio.     

Bandwidth-satisfied multicast trees in large-scale ad-hoc networks

The purpose of this paper is to construct bandwidth-satisfied multicast trees for QoS applications in large-scale ad-hoc networks (MANETs). Recent routing protocols and multicast protocols in large-scale MANETs adopt two-tier infrastructures to avoid the inefficiency of the flooding. Hosts with a maximal number of neighbors are often chosen as backbone hosts (BHs) to forward packets. Most likely, these BHs will be traffic concentrations/bottlenecks of the network. In addition, since host mobility is not taken into consideration in BH selection, these two-tier schemes will suffer from more lost packets if highly mobile hosts are selected as BHs. In this paper, a new multicast protocol is proposed for partitioning large-scale MANET into two-tier infrastructures. In the proposed two-tier multicast protocol, hosts with fewer hops and longer remaining connection time to the other hosts will be selected as BHs. The objective is not only to obtain short and stable multicast routes, but also to construct a stable two-tier infrastructure with fewer lost packets. Further, previous MANET quality-of-service (QoS) routing/multicasting protocols determined bandwidth-satisfied routes for QoS applications. Some are implemented as a probing scheme, but the scheme is inefficient due to high overhead and slow response. On the contrary, the others are implemented by taking advantage of routing and link information to reduce the inefficiency. However, the latter scheme suffers from two bandwidth-violation problems. In this paper, a novel algorithm is proposed to avoid the two problems, and it is integrated with the proposed two-tier multicast protocol to construct bandwidth-satisfied multicast trees for QoS applications in large-scale MANETs. The proposed algorithm aims to achieve better network performance by minimizing the number of forwarders in a tree.     

QoS multicast routing in cognitive radio ad hoc networks

In this paper, we discussed the issues of QoS multicast routing in cognitive radio ad hoc networks. The problem of our concern was: given a cognitive radio ad hoc network and a QoS multicast request, how to find a multicast tree so that the total bandwidth consumption of the multicast is minimized while the QoS requirements are met. We proposed two methods to solve it. One is a two‐phase method. In this method, we first employed a minimal spanning tree‐based algorithm to construct a multicast tree and then proposed a slot assignment algorithm to assign timeslots to the tree links such that the bandwidth consumption of the tree is minimized. The other is an integrated method that considers the multicast routing together with the slot assignment. Extensive simulations were conducted to show the performance of our proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.     

下一代网络中基于遗传算法的QoS组播路由算法

向用户提供多媒体业务是下一代网络业务最基本、最重要的要求,QoS组播路由技术是网络多媒体信息传输的核心技术之一。该文给出了支持QoS组播的网络模型,对已有的QoS组播路由算法进行了优化,提出了适用于下一代网络的基于遗传算法的QoS组播路由算法。仿真实验表明,这种算法收敛速度快,可靠性高,能够很好地满足下一代网络QoS组播的需求。