The Research On Survivablity Measure Model And Topology Optimization Of Wireless Sensor Network

Wireless sensor network is formed by sensor nodes through self-organized way, which have signal acquisition, data processing, wireless communication and other functions. It is widely applied in military surveillance, environmental monitoring, medical and so on. Due to the sensor node’s energy, computing power and communication is limited by a certain degree of limitation, especially the network is deployed in easily damaged and can’t be contact environment, so ensure the Survivability of wireless sensor network is a priority problem when the network is designed.So the research on survivability of wireless sensor network(WSN) is one of the most important problems.In this dissertation two strategies of improving survivability of network are discussed:founds model of survivability and netwok topology optimization:1. Based on node betweenness centrality and entropy theory, a betweenness entropy measure model is proposed. The importance of node is significant to reliability analysis of networks and the design of topology structure. The concept of betweenness centrality is proposed in a "data-centric"approach by combining wireless sensor network.Using this evaluation method can effectively measure the importance of node. Based on this, we advanced the betweenness entropy measure model, to reflect the distribution of betweenness center in the network node, so as to achieve the aim of measuring survivability of wireless sensor network.The simulation results show that the evaluation method is reasonable and effective.2. According to the description of the cut point in the graph theory and the direction of data flow in wireless sensor network which has an important influence on the network node importance, the concept of wireless sensor network cut point is proposed. The sink node location is fully considered based on this concept. Based on the existing study of cut point determination algorithm, WSN cut point decision algorithm is proposed.Experiment results show that the algorithm can accurately identify the cut point existing in the network.3. Key wireless sensor network node failure often leads to the collapse of the entire network, especially cutting point in WSN.So the protection of the network cut point can assure the connectedness of network and improve survivability of wireless sensor network.In order to solve this problem, a strategy is advanced to protect the cut point:neighbor nodes of cut point constitute of2-connected Harary graph and make up local3-Connected graph with its neighbor nodes. Simulation results show that the strategy can effectively protect cut point, and achieve the goal of improving the survivability of wireless sensor network.