【作者】 何芳；

【导师】 刘晓明；

【作者基本信息】 重庆大学 ， 信号与信息处理， 2010， 硕士

【摘要】 无线个域网(WPAN)的应用越来越广泛,但为了满足用户更高的需求,还需要在保证QoS的前提下进一步提高系统的覆盖范围和数据传输速率。无线Mesh网络是一种高速率高容量的分布式多跳网络,可以较大地扩展接入点的覆盖范围,提高系统的数据传输速率。将Mesh思想应用于WPAN的构建能够解决WPAN的一些缺陷,因此,研究基于WPAN的无线Mesh网络路由协议对于无线Mesh网络的应用具有重要意义。本论文从应用的角度,分析了无线Mesh网络的网络结构类型,着重阐述了其技术优点;重点研究了IEEE802.15.4协议的物理层(PHY)和媒体访问控制层(MAC);在IEEE802.15.4协议基础上构建了Mesh子层;讨论了逻辑地址分配和网络自配置中的地址溢出问题;针对该问题提出了分区网状自适应树路由算法,以更进一步改进网络性能。Mesh子层的构建是实现基于WPAN的无线Mesh网络的关键所在。论文在重点研究了IEEE802.15.4协议PHY层和MAC层后,在MAC通用部分子层和特定业务汇聚子层之间构建了Mesh子层,并根据IEEE802.15.4协议中PHY和MAC层的超帧结构设计了Mesh子层帧结构;在Mesh网络地址分配中引入自适应块地址分配,并详细阐述了Mesh网络的组网过程。路由协议是提高网络系统性能的关键。论文通过对已有的簇树算法、AODVjr和网状自适应树路由协议进行分析,提出了WPAN Mesh网络存在的地址分配和网络覆盖的问题;通过采用分区树,将网络划分成若干个逻辑分区,构建了一种新的分区网状自适应树,并提出了一种改进的分级网状自适应树路由算法以适应WPAN Mesh网络。最后,论文利用NS2软件完成了对算法的仿真,仿真结果表明,在WPAN中引入Mesh结构,有效回避了路由中的单点失败问题,并且在不增加路由开销和网络负载的情况下扩大了网络覆盖范围,并有效减小了端到端时延,提高了报文发送成功率和通信效率,在不同规模的网络中均保持了较好的性能,为提高无线个域网的覆盖性和可靠性提供了理论依据。更多还原

【Abstract】 The application of wireless personal area network(WPAN) is more and more widely. However, in order to meet the more needs of users, the data transfer rate and network coverage need to be further improved under the premise of guaranteeing QoS. Wireless mesh network is a high-speed and high-capacity distributed multi-hop network.The coverage of access points can be expanded in large-scale. The transmission rate and reliability of the system also can be improved. Thus, the construction of mesh applied to WPAN can solve some flaws in WPAN. So the research of wireless mesh network protocol based on WPAN is important for the application of wireless mesh network.As the view of application point, the type of network structure and technical merits in wireless mesh network were analyzed. The physical layer and media access control layer of IEEE802.15.4 protocol were mainly studied. The mesh sublayer was built on IEEE802.15.4 protocol. The questions of logical address assignment and the address overflow in network selfconfiguration were discussed. Subtree mesh adaptive routing algorithm was put forward against the question to improve the performance of the network.The construction of is the key to achieve wireless mesh network in WPAN. After a careful study of physical layer and media access control layer of the IEEE802.15.4 protocol, the mesh sublayer was constructed between MAC common part sublayer and the service specific convergence sublayer. According to superframe structure in PHY and MAC layer of IEEE802.15.4 protocol, the mesh superframe structure was designed. The adaptive block address allocation was introduced in address allocation of the mesh network. The process of mesh device joining or leaving the network was described.Routing protocol is the key to improve the performance in the network. The existing mesh routing protocol such as cluster tree algorithm,AODVjr and mesh adaptive tree routing protocol were analyed. The issues in address allocation and network coverage was proposed in WPAN mesh network in this paper. The network was divided into several logical subtree through the use of subtree. A new subtree mesh adaptive tree was constructed. At the same time, an improved hierarchical mesh adaptive tree routing algorithm was proposed to accommodate WPAN mesh network. Finally, the simulation of the algorithm was completed by NS2. The simulation results show that the introduction of WPAN mesh structure effectively avoid a single point of failure problem of the routing, and the algorithm expand the network coverage with not increasing the routing overhead and network load. It also effectively reduces the end-to-end delay, increases the packet delivery ratio and communication efficiency. It maintains a good performance in the networks of different size. It provides a theoretical basis for enhancing the coverage and reliability of WPAN.更多还原