Research On Topology Control Algorithm For Wireless Sensor Networks

Wireless sensor networks are self-organized multiple-hop networks which are composed of lots of low-cost sensors with abilities of sensing, data processing and wireless communication. In wireless sensor networks, the power of the nodes is usually supplied by batteries which energy is limited, and the nodes work in complicated and dangerous regions, so their energies could not be supplemented or replaced. Consequently, reducing power consumption, improving validity of network, and prolonging the network lifetime are the most important problems of wireless sensor networks. It is especially important to design appropriate and efficient energy-used topology control algorithm for sensor networks.LEACH algorithm is a kind of hierarchical topological control algorithm for wireless sensor network. It distributes energy consumption averagely throughout the nodes in the network through selecting cluster nodes randomly. Compared with conventional routing protocols, LEACH can prolong the network lifetime. However, assumptions of LEACH algorithm cannot guarantee cluster heads averagely distributed in actual applications. It will burden some cluster heads, reduce energy utilization. Based on the analysis of LEACH algorithm, an improved algorithm(AOW-LEACH) is proposed in this paper. This algorithm optimizes the selection of cluster head in LEACH algorithm. By setting weights including the residual energy of nodes, the average distances between nodes and nodes' degrees, the best nodes can be chosen as cluster headers. At the same time, the improved algorithm will no longer cluster after clumping in the initial stage, just update cluster head in the original cluster, and adjust locally according to the actual situation. It can reduce the energy consumption of cluster dynamically in the entire network, improve validity of network, ensure the advantages of LEACH algorithm. Simulation results show that the improved algorithm is much better than LEACH in lifetime, LBF and HFLIn addition, although the design between power control and clustering algorithm with different emphasis, their effects all have advantages. Therefore, another work of this article is to combine power control and cluster algorithm. In this program, first the nodes' degrees, the residual energy of nodes and so on will be considered in the cluster head selection, and a optimized network clustering will be obtained, then the power control can be used in regulating the transmit power of cluster heads to make the cluster capacity reasonable. So the aim reducing the network energy consumption from two aspects will be achieved. This clustering algorithm optimizes cluster head choosing, balances the whole networks energy consumption, and prolongs the networks lifetime. Finally the simulation demonstrates the effect of this algorithm.