Wireless Sensor Network Node Scheduling Algorithm

Wireless sensor network (WSN) is composed of a large number of sensor nodes limited by finite energy, so to save energy and prolong the network lifetime, is the main purpose of designing algorithms in WSN. As the core issue of WSN, network coverage control technology through node scheduling and other means to make the redundant nodes work in turn without affecting the original network coverage performance, so as to reduce the nodes' energy consume, extend the network lifetime, optimize the network coverage.This paper introduced the frame, advantages, key technologies as well as the development and trend of WSN in brief initially, after that analysed the theory basis, node coverage model, typical node scheduling algorithm that related to coverage problem in WSN. Then the paper provided a coverage-preserved algorithm CPNS based on bool coverage model and a node scheduling algorithm NSBP based probability coverage model respectively. Many redundant nodes after random deployment in WSN would increase unnecessary energy consume. The main purpose of algorithms proposed in this paper is to reduce node's energy consume and extend the network lifetime. CPNS gave a method to judge whether a node is redundant in the beginning, and then involved the elements of energy and neighbor information during node scheduling, the node with lowest energy executed the redundance judgement first. If nodes have the same weight, nodes with bigger ID went first. Thus, node's energy can be balanced better. NSBP firstly defined the concepts like coverage point, network coverage percentage, total coverage point, then to estimate a redundant node under probability coverage model.After that, node scheduling began. Probability coverage model can response the WSN's application environment more reasonable.The simulation results show that, CPNS has a good performance of energy efficiency and load balancing. Compared with Sponsored Sector algorithm, CPNS used less active nodes to guarantee the network coverage, reduce the coverage redundance better, and CPNS greatly extended the node's lifetime. NSBP had a good ability to describe the network coverage, it can obtain better network coverage.