Design Of An Energy-efficient Double Rounds Clustering Protocol In Wireless Sensor Networks

Wireless Sensor Network (WSN) is one of the most active and important technologies in information area. Its development and application will greatly change our daily life. But as a new technologues, there are many difficult problems to be solved. One of the most important problems is sensor nodes' energy restriction. How to improve the node's energy efficiency must be considered before using it in large commercial area.Nowadays, experts in this area have done many researches about energy efficiency in WSN. As energy efficiency problem relates to nodes, networks, software, hardware and algorthm, there is no perfect solutions and uniform standard. Therefore, in this paper we focus on the communication aspect to present a new protocol for WSN to improve energy efficiency. It is called Energy-Efficient Double rounds Clustering Protocol (EEDCP) which can prolong the network lifetime.The EEDCP is based on the typical clustering protocol LEACH, but we have done many improvements. The main improvements are as follows:1. For the election of cluster head nodes, we improve the random probability of head election arithmetic of LEACH to introduce a new parameter, "residual energy", in EEDCP arithmetic for energy proportion.2. For EEDCP topology, as well as LEACH, we use the hierarchical topology. But we also combine flat topology with it. EEDCP allows the node solo, which doesn't cluster with others base on the distance between it to the sink and to the cluster heads. This hybrid topology can reduce energy consumption.3. For the inter-cluster communications, we change one hop routing of LEACH into a location-based routing which uses one hop or two hops based on the distance to sink node. It can solve the problem that father nodes will die earlier. So the nodes' energy-efficiency can be increased.4. Because it consumes much energy for nodes to send or receive control messages in the process of network clustering, our EEDCP uses double rounds clustering instead of every round clustering. That is to say, the clusters heads change once enery two rounds.5. we use TDMA, CDMA in intra-cluster and inter-cluster communications. We use the clock synchronization and node-sleeping strategy to improve the performance of EEDCP protocol.We simulate EEDCP on Matlab platform, comparing it with LEACH. The results show that our EEDCP is better than LEACH. It improves the energy performance of network by 33%～82%.