An Energy-efficient MAC Protocol For Wireless Sensor Networks

Wireless sensor network(WSN) consists of massive small sensor nodes which are located in monitoring region, the target of which is to cooperatively sense, collect and process the information of objects in the coverage area, then send the information to the observer through wireless communication. It can be widely used in military applications, medical treatment, traffic, environment monitoring and so on .Medium Access Control (MAC) Protocol, which decides how to share the wireless channel, allocates the limited communication resource among nodes and a good MAC protocol can save lots of energy and reduce collision.Firstly the thesis analyzed the research background and the current situation at home and abroad, and then discussed the structural characteristics of wireless sensor networks and other content, in which indicating the energy consumption of the wireless sensor network; Then, the thesis compared and analyzed the MAC protocols of the wireless sensor Network, focusing on competition-based MAC protocol S-MAC, T-MAC protocol in detail. From the shortcomings of the thesis proposed a new study of the improved protocol basing on the random work sleep scheduling mechanism; Finally, the thesis simulated the improving the MAC protocol using NS2, showing that the performances of the improved protocol are better than the original in improving energy efficiency, delay, throughput and so on from the analysis of simulation results.The innovation of this thesis was to proposed a new improved protocol using random work sleep scheduling mechanism, and in the new protocol the nodes of a same virtual cluster didn't have fixed duty cycle, but could changing along of the network load, and only the nodes who had to communicate with others worked in synchronous mode, and the nodes who had no message to send worked in asynchronous mode, so that in a cycle it can provided more nodes communications services without affecting each other, similar to TDMA mode, and have improved the efficiency of time resources, and enhanced network the performance of the network at the same time not increased the complexity of the hardware nodes.