Research Of MAC Protocol In Wireless Sensor Network Based On Competition

Wireless sensor network is a set of informational collection, informational processing, informational transmission and information management. It applied to an integrated intelligent information system. By combining sensing technology with wireless communication technology, wireless sensor networks provide a new effective method for human interaction and the objective physical world. It is precisely because of its potentially enormous value, wireless sensor network has become one of the most active research filed in today's computer information field.In wireless sensor networks, the MAC layer protocol determines how to assign the channel among sensor nodes. A fair, robust and efficient MAC protocol is very essential in improving the performance of wireless sensor networks. Based on the analysis of several typical MAC protocols of wireless sensor networks,this thesis studies the classic S-MAC protocol which is based on competition. By inheriting the excellent idea of S-MAC protocol, this thesis improves it for the shortage that the node idle listening time is too long. The improved protocol reduced the idle listening time of the nodes which have no data to send and the energy consumption through a unified data delivery time, in another way, it reduced the number of boundary nodes and enhanced the network connectivity through virtual cluster fusion technology. Both theoretical analysis and simulation results show that the improved S-MAC protocol further reduced network energy consumption under the premise of maintain the original communication latency, and prolonged the lifetime of the network.As application example, this thesis describes a wireless sensor network application project--intelligent transportation system based on wireless sensor networks. It described the overall design of the system and the design idea of system nodes'software and hardware.