Research On Prolonging The Lifetime Of Wireless Sensor Network Based On Grid Algorithm

Wireless Sensor Networks(WSN),which is composed of the convergence of sensor, nested computation, networks and wireless communication technologies, is a novel technology about acquiring and processing data information. WSN can be found applications with great foreground and dominance in many fields, such as environment, health, military, space exploration, disaster prevention and so on. More and more researchers from academic circles are engaged in the development of WSN. Sensor nodes usually work outdoors and are battery-powered, which limits the lifetime of WSN.This paper pays special attention to how to save energy and prolong network lifetime. Firstly, it introduces characteristics, applications, related research areas and foreground. Then current routing protocols in wireless sensor networks are gived a comparative analysis. In view of the existing energy-saving strategies, we make the study from the following three aspects:Some protocols only consider energy consumption of the entire network and ignore that of the single node, which lead to the failure of WSN. In order to prolong system lifetime and enhance energy efficiency, a novel grid-based energy efficient routing (GEER) algorithm for WSN is presented. Through formula extrapolation this algorithm gives the optimum grid size to save energy. GEER uses a cost function of both distance and residual energy as a routing metric to elect the best route. GEER and traditional routing algorithms are evaluated in NS-2. Simulation results show that GEER has greater number of nodes alive, longer lifetime of network and better scalability.A new energy efficient routing (Weight-Directed Energy Efficient, WDEE) algorithm to meet the requirements of the continuous application model is also proposed in this paper. This algorithm groups nodes within grids and expresses the residual energy by a small number of energy levels. WDEE can transfer data quickly to the sink using the directional information and route weight value of grids as well as balance total energy consumption of all grids. Detailed simulations of sensor network environments indicate that this algorithm improves energy efficiency and proportions energy consumption of all sensor nodes to extend network system lifetime.Nodes in the practical WSN are distributed densely and their sensing ranges overlap each other, which produce much redundant data. Therefore, how to conserve energy by decreasing redundancy is an essential problem. Based on the concept of sensing radius, we presents an algorithm of active node selection to extend the lifetime further, which combines the active node selection algorithm and WDEE algorithm. Thus, it increases the number of nodes in the sleep state to prolong network system lifetime.