基于证据理论的无线传感器网络链式路由算法

摘要

目前存在的许多链式路由算法在链首选举时仅考虑了节点剩余能量,基于Pegasis的节能协议(energy-efficient Pegasis-based protocol,EEPB)算法虽然综合考虑了节点剩余能量与节点到基站的距离两方面因素,但简单地将这两方面因素加权的综合考虑并未完全消除两种因素判决结果的不一致性.基于此,提出一种基于证据理论的链式路由算法(chain routing algorithm based on evidence theory,CRET).首先,在链首选举时利用D-S证据理论,选用节点剩余能量和节点到基站的距离两个评价指标来确定节点是否能成为链首节点,分别建立隶属度函数,进而求得基本概率分配值,再利用D-S证据理论合成法则将两个评价指标进行融合判决1其次,为了避免长链的产生,CRET算法在建链阶段考虑了已经加入链的节点,并且所有节点都是与距离自己最近的节点相连成链.仿真结果表明,CRET算法在平衡节点能耗和延长网络寿命方面比EEPB算法具有更加优越的性能.%At present,only the remaining energy of nodes is considered when electing the leader node in existing chain routing algorithms.Although EEPB adopts the remaining energy of nodes and the distance between nodes and the base station(BS) to determine which node is qualified to be the leader node,simply weighting these two factors does not completely eliminate the inconsistency of the two decisions.Accordingly,a chain routing algorithm based on evidence theory called CRET is proposed.In the leader node election stage,CRET utilizes two evaluation indexes which are the remaining energy of nodes and the distance between nodes and the BS to confirm which node is chosen as the leader of the chain by Dempster-Shafer (D-S) evidence theory.In the CRET algorithm,two membership functions are respectively established to describe two evaluation indexes,and the basic probability assignment functions of the two indexes are acquired.Then the combination discipline of D-S evidence theory is used to determine the final results of two evaluation indexes.In the chain construction stage,in order to avoid the generation of long chain,the node which has joined the chain is taken into account,and each one is connected to its nearest node.Simulation results show that CRET has superior performance over EEPB on balancing energy consumption among the nodes and extending the network lifetime.