Wireless Sensor Networks, Clustering Routing Protocol

Wireless Sensor Networks (WSN) is consisted of a large number of micro-sensor nodes by wireless links. It is an integration of information collection, transmission and processing technology, also one of the top technology in future. The characteristics of low cost, flexible network make it has broad application prospect, such as military, environmental monitoring, medical and space exploration etc.Because the energy supply of WSN is restricted and cannot change battery, the networks always have a lifetime limit. In order to extend the lifetime, we had to control the energy consumption in networks. The network routing protocols is a key influence factor of energy consumption in data transmission. Related studies have shown that the hierarchical routing protocol of WSN is effective in saving energy.We did study aim at the clustering routing protocols, analyzed various clustering algorithms. Base on the analysis, an improved algorithm named Base Station Aided Clustering Routing (BACR) is presented in this paper. In BACR, an adjustment function is introduced into the process of cluster head election. This adjustment function use the energy factor of nodes, time factor and the relative position between nodes and base station as the parameters, which makes the distribution of cluster heads more reasonable both on time and space. We focused on various function to pick out a most efficient one for this algorithm. After describe the process of BACR, we also analyzed the influence on the suitable number of cluster head by using BACR, then we also analyzed the routing rules after cluster constituted. At last we improved LEACH protocol by BACR, called LEACH-BACR.We simulated the both protocols LEACH and LEACH-BACR in NS2 environment. Simulation result shows that LEACH-BACR is more efficient than LEACH in cluster head distribution, the first node death time and the balance of energy consumption. The simulation verified the effectiveness of BACR.