Design And Improvement Of Routing Protocol For Wireless Sensor Networks

The availability of low-cost hardware such as CMOS cameras and microphones has fostered the development of Wireless Sensor Networks (WSNs), i.e., networks of wirelessly interconnected devices that are able to retrieve multimedia content such as video and audio streams, still images, and scalar sensor data from the environment. It is receiving increasing attention from all lines due to its wide application future.There are various kinds of application-specific routing protocols devised for wireless sensor networks by researchers around the world.A sensor network is a set of sensor nodes that communicate by sending messages over wireless links either directly to destination node or indirectly over a sequence of intermediate nodes. Energy is the most critical resource in the life of a wireless sensor node. Therefore, its usage must be optimized to maximize the network life. That is, the period of time during which the network is operational depends on battery lifetime. Energy conservation is truly a critical issue in WSN, so how to prolong the networks'lifetime is the fast question we should consider because of the limited batteries.LEACH protocol is one of the earliest hierarchical sensor network protocols. The number and position distribution of cluster heads generated by its cluster head election algorithms are unstable. This will reduce the lifetime of the networks.This paper proposes a competitive cluster-head selection algorithm based on energy efficiency, in which additional parameters including the number of chuster heads, the remaining energy level of candidates and their energy cost for transmission are synthetically considered to optimize the process of cluster-head selection. The main idea of our algorithm is to avoid choosing nodes with lower residual energy as cluster-heads, thus to ensure balanced energy-usage among the nodes in the network.Preliminary simulation results show that our protocol greatly improves the performance and efficiently prolongs the network lifetime by about 20%-30%.