【作者】 任光玺；

【导师】 吴玉成；

【作者基本信息】 重庆大学 ， 电路与系统， 2008， 硕士

【摘要】 随着Ad Hoc网络传输多媒体业务需求的增加,相应地提出了服务质量(QoS)的要求。由于Ad Hoc网络本身具有分布式控制、无线信道容量受限以及节点、链路和网络拓扑状态不断变化等特点,支持QoS要求是一项具有挑战性的任务。本文在Ad Hoc网络中QoS问题现有研究的基础上通过分析总结,提出了一些改进算法,构造了一种支持实时业务的Ad Hoc网络QoS服务机制。Ad Hoc网络是由一组带有无线收发装置的移动终端组成的一个多跳的临时性自治系统。随着人们对通信业务要求的不断提高,对带宽、时延、误码率等性能参数提出了不同程度的保障要求,因此要求Ad Hoc网络能够为某些业务提供服务质量(QoS)保障。但由于Ad Hoc网络无线链路的时变特性、网络拓扑结构的动态变化、移动终端设备电池容量受限等特点,使其相对于固定无线网络及有线网络提供有保证且稳定的QoS保障要困难得多,非常具有挑战性。本文首先对目前几种基于带宽和时延约束的QoS路由协议进行了介绍。改进了DSR动态源路由协议使其支持QoS要求。DSR协议是专用于Ad Hoc网络的简单有效的按需路由协议,主要由路由发现和路由维护两个机制组成。DSR协议具有以下优点:允许到目的节点有多条路径、允许由于负载均衡和健壮性等要求选择不同传输路径、容易避免环路、支持单向链路和针对网络拓扑变化可以快速的修护路由。本文总结了当前DSR协议的QoS研究进展,对不同的改进方案加以分类比较,指出了存在的问题。针对Ad Hoc网络中基于资源预留的QoS算法所带来的复杂度问题,本文提出了适合该网络的测量可用带宽算法,并且改进DSR协议使其支持QoS。仿真结果表明,这种改进的QoS路由比原有的路由性能上有较大改进。更多还原

【Abstract】 The general field of mobile Ad Hoc networks is still in its infancy. Particularly, the challenge of providing quality of service (QoS) support is an open problem and remains relatively uncharted territory because of the lack of centralized control, limited node capability, and variability of the links and network topology. This paper, based on the current research, does extensive research and introduces the modified QoS algorithm in mobile Ad Hoc networks.Firstly, dynamic source routing (DSR) is modified to support the QoS requirement. DSR is a simple and efficient routing protocol designed specifically for use in mobile Ad Hoc networks. The protocol allows multiple routes to any destination and allows each sender to select and control the routes used in routing its packets, for example for use load balancing or for increased robustness. Other advantages of the DSR protocol include easily guaranteed loop-free routing, support for use innetworks containing unidirectional links, and very rapid recovery when routes in the network change. It’s presented that a survey of the current research that has addressed the basic concepts and the implementation of QoS routing in the Ad Hoc networks. However, these protocols bring much complexity and the application is different, if not impossible. In this paper, we first develop detailed computations that allow us to estimate the available bandwidth in Ad Hoc networks, and then modify DSR followed by extensive simulation to verify the effectiveness with different environment.After analysis the existiing quality - of - service in mobile Ad Hoc network, bases on AODV protocol draft, this article presents a new QoS routing algorithm. It can be applied in the network which has a QoS operation demand. We also compare this new arithmetic with the Greedy arithmetic, the simulation results indicate that the new arithmetic has low control cost, higher end-to-end connectivity and low transmitting fluctuation.更多还原