【作者】 肖百龙；

【导师】 郭伟；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2009， 博士

【摘要】 移动自组织网络是由一组带有无线收发装置的移动节点组成的，无需基础设施支持的动态可重构多跳自组织网络，能够在不能或不便利用现有网络基础设施的情况下快速展开。它拓宽了移动通信网络的应用场合，可以广泛应用于战场、抢险救灾、应对突发事件、会议或集会等无法得到有线网络支持或只是临时需要通信的环境，是下一代网络的重要组成部分。移动自组织网络所具有的分布式、自组织、多跳、动态拓扑、时变信道、资源受限等特点，给网络协议的设计带来了很大的挑战。本文围绕移动自组织网络的MAC协议和路由算法进行了研究，主要研究了移动自组织网络的MAC层能量消耗模型和基于时隙预约的节能管理模式，以及基于能量有效的伪流言路由算法、基于链路稳定性的伪流言路由算法、路由局部修复算法等。移动自组织网络的寿命很大程度上依赖于节点电池能量的有效利用，设计能量有效的算法来延长网络寿命成为其核心的问题。在第二章中首先建立了MAC层的能量消耗模型，模型包括了节点的发送、接收、空闲和睡眠等状态，考虑了整个网络中所有节点的干扰，分析了冲突引起的重传以及节点偷听导致的能量消耗。在此模型基础上，分析了减少能量消耗的策略，提出了一种基于时隙预约的节能管理模式，传输只在预约的时隙进行，节点在参与通信时保持苏醒而在其余时隙进入睡眠状态，减少了隐藏终端和暴露终端带来的冲突，减少了MAC层的能量消耗。在使用洪泛的路由协议中，很多路由消息的传输是多余的，而流言机制可以显著减少冗余路由消息的发送。第三章在MAC层的能量消耗模型和流言机制的基础上提出了一种基于能量有效的伪流言路由算法。它通过让剩余能量较多的节点优先参与路由建立过程以平衡网络的能量消耗和保证业务的顺利传输，并限制其余节点的参与来节约能量和带宽资源。分析和仿真实验都表明该算法能降低路由控制开销、减少能量消耗，并实现了能量的平衡消耗，延长了网络的运行寿命。为了适应网络拓扑的动态变化，减少路由的失效，需要能发现寿命更长的稳定路由。由于边缘效应，最短路径路由的寿命较短，在节点分布密集的网络中表现更为明显。第四章分析了移动自组织网络中链路和路径有效性的统计特性，并在此基础上提出了一种基于链路稳定性的伪流言路由算法。该路由算法可以发现更稳定的路由，并减少路由控制开销，能较好地适应网络拓扑的动态变化，显著地提高了网络的性能。当多跳路径失效时，路由协议需要对其进行修复，而已有的修复机制会引起很多的开销和很长的端到端时延。第五章针对已有修复机制的不足，提出了一种新的路由局部修复算法，将修复尽量限制在断链的局部范围内，以减少对链路断裂的反应时间和降低路由维护的开销，而且不用考虑失效链路在整个路径上的相对位置，都可以对其进行修复，提高了修复失效路径的能力，有利于提高MANET的可扩展性。仿真表明，这种新的路由局部修复算法明显地提高了网络分组成功接收率和端到端时延等多方面的性能。最后对全文进行了总结，回顾了前面所述的研究工作，并根据目前的情况对未来的研究热点问题作了展望。更多还原

【Abstract】 Mobile Ad Hoc Network (MANET), which consists of a group of mobile nodes equipped with transceivers, is a dynamic reconstructable multi-hop network without the support of fixed infrastructures. It can be rapidly deployed in places where the networking infrastructure neither available nor economical to build. It expands the using of mobile communication networks and can be used widely in tactical battlefield, civilian emergency communication, meetings or conventions. MANET has some characteristics such as distributed, self-organizing, multi-hop, dynamic topology, time-variant channels and limited resources etc., which pose lots of challenges on its protocols. The medium access control (MAC) and multi-hop routing are key technologies in MANET. The dissertation mainly does research on the following content: the energy consumption model of MAC protocol, Slot-Reservation Power Saving Mode (SR-PSM) algorithm, Energy-Efficient based Pseudo Gossip Routing (EEPGR) algorithm, Link Stability based Pseudo Gossip (LSPG) routing algorithm and a new local route repair algorithm.An energy consumption model of MAC protocol is presented for MANET in chapter 2. The MAC modeling includes all operation modes of nodes such as transmission, reception, idle and sleep states. Moreover, the energy consumed in overhearing state and retransmission due to collision is considered. The model takes into account the interference of nodes in the entire system. Based on the analytical model, a Slot-Reservation Power Saving Mode (SR-PSM) algorithm is proposed, in which the transmission will only cocure in the reserved time slots and nodes are just awake when they are a part of a transmission and turn into sleep mode during the remaining time. The mechanism can avoid collisions due to hidden terminal and exposed terminal problems and save more energy than Power Saving Mode (PSM).In routing protocols that use flooding, many routing messages are propagated unnecessarily. Gossiping can be used to significantly reduce the number of routing messages sent. Based on the energy consumption model in MAC protocol and gossip scheme, an Energy-Efficient based Pseudo Gossip Routing (EEPGR) algorithm is presented for MANET in chapter 3. In EEPGR, nodes with more residual energy take priority of participating in routing to balance the energy consumption over the network, meanwhile, the others are confined to save energy and bandwidth resource. The simulations show that EEPGR can decrease the routing overhead, reduce and balance energy consumption and then prolong the network lifetime, so it is feasible and preferable for MANET.When a route is broken for node mobility, route recovery and maintenance are executed. However, these procedures consume many resources and lead to increased delay. To minimize route breaking, it’s important to find a route that lasts longer time. Shortest path route has short lifetime especially in highly dense MANET due to the edge effect. In chapter 4, the statistic results of link and path availability properties in MANET are derived. According to the analysis, a pseudo gossip routing algorithm based on the link stability is proposed. This routing algorithm can select reliable path that can last longer by using fewer routing messages as to be shown by the simulation results.If multi-hop route is failed, routing protocol should maintain it. The previous route repair mechanism causes high control overhead and long packet delay. The problem worsens when mobility is high and many real-time applications do not tolerate such long delays. In chapter 5, a new idea on local route repair which confine the repair to the vicinity of broken links is proposed to decrease the reaction time of route breakage and the overhead of route maintenance. Furthermore, the approach can repair failure links without taking into account of their relative position on the whole path. It improves obviously the ability of dealing with failure links in MANET. Simulations show that the new local route repair algorithm resulted in significant performance improvement, such as packet delivery ratio and end-to-end packet delay.Finally, chapter 6 summarizes the dissertation, reviews the above research work and presents the future research directions.更多还原