Research On Topology Maintenance Algorithm For Mobile Wireless Sensor Networks

Because the mobile wireless sensor network is usually used in the mobile environment,and there are factors such as nodes movement,new nodes join the network,node failure,nodes exit network which made the topology is usually in a dynamic.The communication links between the nodes will be frequently interrupted and established because of the dynamic topology.This case will not only increase the communication overhead,but also accelerate the energy consumption of the node.Therefore,how to effectively maintain the dynamic network topology is a hot spot for mobile wireless sensor networks over the years.Firstly,the background and significance was summarized in the thesis,the concept,characteristics and application of the mobile wireless sensor network were introduced briefly,the current topology maintenance algorithm of mobile wireless sensor network were classified,and some typical algorithms were analyzed in detail.Secondly,the principle and the problems of NAPC algorithm are studied deeply,and the Power Adaptive based Topology Maintenance Algorithm(PATMA)was proposed in this thesis.PATMA algorithm mainly includes three mechanisms as follow: The relay node selection mechanism based on node energy consumption model.The node energy consumption model was used in this mechanism to select the relay node according to the size of the energy consumed that between the nodes send and receive unit data packets to each other,which is improved the overall energy efficiency of the network;The power adaptive adjustment prejudge mechanism.This mechanism will first to check whether there is another spare node in the forwarding set to replace the original relay node.If so,it is replaced directly.Otherwise,the predicting process is initiated.The power was adjusted adaptively according to the prejudge result by the nodes;The maintenance mechanism based on event triggering.The factors that cause the topology to change was classified in this mechanism and the Join events and Break events were set.The maintenance mechanism was triggered when the events were detected by the nodes.The simulation results show that the PATMA algorithm has a significant improvement in the average transmit power,packet loss rate,link average repair time and the number of surviving nodes in the network compared with the NAPC algorithm and XTC algorithm.Then,the general steps of clustering algorithms and topology maintenance algorithm were analyzed and compared.The problems of FDRC algorithm were analyzed and the Weighted Clustering based Topology Maintenance Algorithm(WCTMA)was proposed.The core idea of the WCTMA was calculated the node weight values based on the node mobility and the residual energy,and clustered the network.The control message for topology maintenance was designed.Those messages were used to judge whether the network topology has changed through the whether they were received normally between the nodes.The cluster topology maintenance strategy and inter-cluster topology maintenance strategy were designed according to the different factors such as node movement,new nodes join the network,may caused the topology changes.The simulation results show that compared with the existing FDRC algorithm,WCTMA algorithm has significant improvement in the average residual energy,packet delivery success rate and network life cycle.Finally,the whole work of the thesis was summaried,and the future research direction of topology maintenance algorithm for mobile wireless sensor networks was pointed out.