能耗均衡的无线传感器网络无标度容错拓扑模型

摘要

Network lifetime is an important indicator to evaluate the performance of wireless sensor networks.The fault tolerance of scale-free topology is beneficial to prolong the network lifetime,but the uneven construct will lead the imbalanced energy consumption,then the imbalanced energy consumption will shorten network lifetime.In order to solve the problem,a network energy consumption model is established based on the residual energy of node and the distance between nodes,and the network lifetime is evaluated according to this model.The influence of node energy and node distance on network lifetime is analyzed.We found that node energy is positively related to network lifetime,and the node distance is negatively related to network lifetime.Then the influencing relationship is introduced into the preferential connection mechanism of scale-free topology,a dynamic evolution model which can balance the energy consumption and tolerant node failure is proposed in this paper.In the model,the ratio of distance between the nodes to residual energy of the nodes is regarded as fitness function,the addition of new links and reduction of some old links are also introduced into this model,and the power-law distribution characteristic of node degree in this evolution model is analyzed by the mean field theory.Thus a topology which has scale-free and fault-tolerant properties is obtained.To verify the correctness of the theoretical analysis and analyze the network performance,extensive simulation experiments are carried out in the MATLAB simulation platform.Compared with other classical models,the simulation results show that the degree distribution of the topology obeys the power-law distribution characteristic,and it can not only balance the energy consumption of nodes and network,prolong the network lifetime,but also enhance the capacity of fault tolerance and intrusion tolerance.%网络生命期是衡量无线传感器网络性能的重要指标,无标度拓扑对节点随机失效的强容错性在一定程度上能够延长网络生命期,但是其拓扑结构的不均匀会造成网络能耗的不均衡.为此,针对无标度拓扑能耗不均衡导致网络生命期缩短的问题,该文考虑节点剩余能量和节点间距离,建立能耗模型,根据此模型评估网络的生命期,分析节点能量和节点间距离对网络生命期的影响,得出网络生命期与节点能量正相关,与节点间距离负相关的关系.将此关系应用于无标度拓扑演化规则的择优连接机制中,提出一种能够均衡网络能耗的无线传感器网络容错拓扑动态演化模型.在建模过程中,将节点剩余能量与节点间距离的比值作为适应度函数,并考虑网络拓扑变化时存在的链路增减的动态行为,利用平均场理论分析此演化模型节点度分布的幂率特性,最终得到一个具有无标度特性的容错拓扑.在MATLAB仿真平台下,分析由所提演化模型形成拓扑的度分布形式,验证出该拓扑的度分布服从幂率特性.同时,将此模型与其他经典模型进行网络性能对比分析,验证出该模型不仅能够均衡节点和网络的能量消耗,延长网络的生命期,还能够增强网络的容错和容侵能力.