Research On Wireless Sensor Networks Routing Protocol And Node Localization Technology

Wireless sensor network(WSN)is spontaneously composed by a large number of micro sensor nodes deployed in surveillance area,which is a multi-hop self-organizing network.It's recognized that WSN is data-centric.It's vital that nodes' data be transmitted to base station with highly efficient.Firstly,PEGASIS is studied and E-PEGASIS is proposed according to the correction of PEGASIS in this dissertation.The network is divided into grids,and the communication link is constructed grid by grid in E-PEGASIS.The link avoids long communication distance in the communication link which is constructed through greedy method by PEGASIS.A method of computing probabilities of nodes being cluster heads is proposed in E-PEGASIS.The nodes cost more will have less chance to become cluster heads.Meanwhile,the node with most energy is chosen as cluster head in every round,which belongs to the possible cluster head set.The method balances energy among nodes and fully uses the two nodes in link end.Secondly,TECH(tree-based energy-efficient clustering hierarchy)is proposed based on E-PEGASIS,which is scale adaptive.The network is divided layer by layer from the base station,which is located at the center of network.A number of small clusters are established in each layer.Then,clusters,which are adjacent,will balance their sizes.And E-PEGASIS is used in each cluster.Finally,uniting theory with practice,this dissertation proposes an indoor positioning system,which combines ZigBee and ultrasonic wave.The system consists of computing terminal,mobile node and fixed nodes.The fixed nodes are located at the same plane and the mobile node lie below them.The mobile node sends the data to computing terminal after receiving at least three fixed nodes' TDOA data of ZigBee and ultrasonic wave.The computing terminal computes the position of mobile node using the trilateral measurement method.The simulation results show that the proposed E-PEGASIS prolongs network lifetime and the energy between nodes is balanced.The proposed TECH works efficiently and steady with network scale increasing.The positional accuracy of proposed indoor positioning system is less than 10 centimeters.