Research And Improvement Of Power Control Based Algorithm In Wireless Sensor Networks

Wireless sensor network consists of large number of sensor nodes with limited battery power, which are randomly deployed over certain area for several applications. Due to limitations of the application environment, replenishing energy by replacing and recharging batteries on hundreds of nodes in most of the sensor network applications, particularly in harsh terrains is very difficult and sometimes infeasible. Therefore, reducing the energy consumption of the network nodes to extend the network life cycle is one of the key issues in wireless sensor networks.In wireless sensor networks, communication activities using higher transmission power and forwarding of similar data packets along the multi-hop paths are main consumers of sensor energy. So, by adjusting the transmission power of nodes within the appropriate range, not only can effectively prolong the survival time of the network, but also improve network performance.In this paper, an improved power control based algorithm for the multi-hop wireless sensor network is proposed to construct an energy efficient tree topology. The algorithm is divided into three interrelated part, the first phase is the construction phase. It is initiated by the sink node, using the minimum transmission power to discover neighbor nodes. As gaps exist in the network, the construction phase will be ended in an certain time; then, group expansion phase begins; the prior completion of group members using the maximum transmission power to connect the nodes beyond the gap, and then calculate the effective power level according to the proposed algorithm respectively, these two phases alternate with each other; then a complete hierarchical network topology will be formed. Simulation results show that our distributed protocol can achieve energy conservation up to an optimum level and can extend the network lifetime as compared to original algorithm without any improvement.