【作者】 姚伟斌；

【导师】 鲁东明； 董亚波；

【作者基本信息】 浙江大学 ， 计算机应用技术， 2008， 硕士

【摘要】 近年来,无线传感器网络的应用越来越广泛。特别它应用于野外的环境监测,如森林火灾、洪水地震、文物保护的监控。但无线传感器节点的传输距离近,在野外大规模部署的复杂环境下,传感器节点采集的数据如何快捷、可靠地获取是个难点。针对无线传感器网络远距离的数据采集,有很多应用采用了一种低成本的远距离透明传输设备,如数传电台、数传模块。它不依赖于电信基础设施,可靠传输距离达几公里。但传输速率低,无冲突检测和信道估计的功能,缺乏网络自组织能力,进一步限制了网络规模的扩大和传输可靠性的提高。为此,本文构建了一个多跳无线网络:该网络由一个路由节点和多个中继节点构成。中继节点负责将无线传感器网络中的数据转发到路由节点。路由节点负责将数据从中继节点转发到Internet网络。路由节点通过源路由的方法对中继节点进行轮询,并获取数据,轮询路径可以多跳,轮询路由在路由节点中集中计算,各节点间的信道质量也从中继节点得到。在针对上述网络的协议中,由于中继节点的硬件没有信道估计的能力,本文运用统计包传输成功率的方法估计自身与邻居节点的信道质量。在被路由节点轮询到时,各中继节点将这些信道质量连同数据一起发给路由节点。路由节点在获取了整个网络节点间的信道质量之后,集中式地计算各链路的通信代价,通过Dijkstra算法找出到每个中继节点代价最小的链路。然后,路由节点即可运用源路由的方式轮询中继节点。该协议能使网络中的各节点避免信号冲突,使各链路的传输效率达到最优。基于上述协议,本文设计了路由节点和中继节点的软硬件体系结构。在路由节点中采用的嵌入式数据库存储数据,并使用带确认的网络通信协议发送数据,实现了可靠的数据存储与传输。实验和现场应用证明,本文设计的多跳无线轮询网络自组织性强,易于部署,效率高,在远距离野外环境的数据采集方面取得了良好的效果。更多还原

【Abstract】 In recent years,WSN(Wireless Sensor Network)becomes more and more popular in data gathering applications,especially in wildland environment monitoring of the forest-fire,flood,earthquakes and heritages.However real-time remote data gathering is hard to achieve due to the limited coverage area of WSN node.At present,data RF module based devices are widely used for data gathering.They are low in cost,and can transmit data in a long distance without pre-deployed infrastructure facilities.But the scalability and reliability of these devices are limited because of the lack of contention detection,link quality measurement and self-organization.This thesis constructs a wireless multi-hop network which consists of a Router(Route Node)and several Relayers(Relay nodes)to overcome above disadvantages.Relayer relays the data from WSN to the Router.Router transmits the data from the Relayers to the server of Internet.Router polls Relayers for data gathering by using multi-hop polling paths based on DSR(Dynamic Source Route)which are centrally computed.Each Relayer estimates the link qualities to neighbor node.The protocol of above network follows below:At first,Relayers estimate the link qualities by counting the sequence of packets received from neighbors.Once a Relayer is polled,it transmits the link qualities and sensors’ data to the Router.After obtaining the link qualities information of entire network,the Router calculates the link costs and finds the shortest path to each Relayer with Dijkstra algorithm and can start polling.Every node in the network now is contention-free,and achieves the optimal channel utilization.This thesis designs a hardware platform and software implementation for Router and Relayer.In order to make the data delivery more reliable, the Router stores the data in an embedded database,transmits the data with an ARQ(Automatic Repeat-reQuest)socket protocol.Experiments and the field application of the wireless multi-hop polling network prove effectiveness in remote data gathering,and the scalability,reliability,easy deployment and high channel utilities of the system is further analyzed in the thesis.更多还原