Research On Routing Protocol Based On Hierarchical Wireless Sensor Networks

Wireless sensor networks(WSNs)are widely used,and the network scale is generally large,requiring a large number of sensors to perform environmental sensing tasks.In most cases,the sensors rely on battery power and cannot continue to work once the power is exhausted.Therefore,reducing the working energy consumption and prolonging the working time of sensors become the focus of research on wireless sensor networks.Structure determines the characteristics and performance of the WSNs,and hierarchical structure is one of the most widely used structures of WSNs because of its broad expansibility and route maintenance.The complete routing protocol of hierarchical WSNs is divided into two parts:the first part is cluster establishment;the second part is data transmission between clusters.In this thesis,the two parts are studied respectively,and the effectiveness of the proposed method is verified.In this thesis,multi-layer energy-efficient unequal clustering routing protocol is proposed to improve the first part,and Dijkstra algorithm is selected as the data transmission method between clusters in the second part of the protocol.In this thesis,the whole sensing region is divided into several concentric rings.In order to alleviate the common "hot spot"problem of hierarchical routing protocols of WSNs,a multi-layer correction factor is proposed.According to the characteristics of the network,this thesis deduces the optimal cluster head selection ratio and proposes to replace the classical circular clustering model with the energydistance weighted Voronoi polygon clustering model.Simulation results show that the proposed method can save energy,prolong the network lifetime,and improve the energy efficiency of the network compared with some existing methods.This thesis proposes an improved ACO(Ant Colony Optimization)routing protocol based on multi-layer unequal clustering to improve the second part,and the first part of the protocol adopts the improved method proposed above for the first part.An improved ACO method is proposed for the path planning of data transmission between clusters.Based on the parameters of the classical ACO,the heuristic factors such as the degree of nodes,the times of relay and the remaining energy of nodes are introduced into the algorithm.When selecting the next hop node for cluster heads,the transition probability of each reachable node should be calculated according to the formula of improved ACO,and the next hop should be selected by roulette.In this thesis,the calculation of pheromone concentration increment is adjusted according to the characteristics of hierarchical WSNs.Simulation results show that the proposed method is superior to some existing protocols in terms of energy saving and network lifetime prolonging.