Research On The Energy Optimization Of WSN Based On Improved SEP Protocol

Wireless Sensor Network(WSN)has a wide range of application scenarios,which is a new type of wireless network.However,the energy constraints of WSN restrict the application of WSN seriously,which is an urgent problem and must be solved.This thesis will mainly studies the efficiency and balance of energy consumption in WSN.The Stable Election Protocol(SEP)will be improved to balance energy consumption and enhance utilizatione of energy consumption to prolong the life cycle of WSN,which is a clustering protocol for energy heterogeneous WSN.The main work of this thesis is as follows:(1)The architecture,the characteristics,applications and key technologies of WSN are studied.Clustering protocols and energy routing protocols of WSN are studied.The classification of clustering protocols and routing protocols are summarized.Low Energy Adaptive Clustering Hierarchy(LEACH)and SEP protocol including their advantages and disadvantages are researched.The working mechanism of energy routing and energy multipath routing is analyzed.(2)There are several problems in SEP protocol,such as the problem of the cluster head election where the residual energy of each surviving node is not considered.The energy reference factor is used to improve the cluster head election formula of WSN,which is obtained by calculating the difference between the residual energy of each surviving node and the average residual energy of surviving nodes.Nodes with large residual energy are more likely to become cluster heads by the improved method.Member nodes in a cluster which with low residual energy but far from cluster head are defined as “dangerous nodes” in this thesis.The problem of premature death of “dangerous nodes” has not been solved in SEP protocol too.So the distinguishing mechanism of "dangerous" nodes” is proposed to balance the energy consumption of nodes and prolong the life cycle of WSN,which allow qualified nodes to use other nodes with sufficient residual energy to transmit information indirectly.(3)In view of the lack of energy-efficient routing mechanism in SEP protocol,the heuristics and global pheromone updating formulas are improved based on ant colony system(ACS)which has strong robustness and the ability to adapt to topology transformation of WSN.On the basis of the improved SEP protocol and the improved ACS-based routing,the transmission process from cluster head to sink node is improved.