Research In Intelligent Multiple Access Technology For Distributed Wireless Network

Wireless distributed network has attracted more and more attention as a rapidly developing technology in telecommunication. The most important part in developing a distributed wireless network is to design the media access control (MAC) protocol, which is focused on the sharing of limited channel resource among different users. At present the commonly used MAC protocols are TDMA and CSMA protocol.In this paper, a hybrid MAC protocol, which we called H-MAC, is proposed to achieve better multiple access performance in single-hop wireless distributed network. We find out the points of intersection on the basis of simulating the throughput curves of CSMA and TDMA. Then we choose a suitable point of switched from the points of intersection. In accordance with current traffic, we choose CSMA protocol when the arrival rate is low in order to make good use of channel, and we choose TDMA protocol when the arrival rate is high in order to avoid collision. The simulation results show H-MAC protocol gives better performance when the channel access delay and the rate of success are within a certain range.Then an improved dynamic TDMA protocol base on traffic is proposed for the shortage of H-MAC protocol. Simulate the throughput of network, channel access delay and rate of success with different number of stations and different channel rates. In accordance with results, we adjust the dynamic access probability, called q. Results of the simulation shows that the new dynamic TDMA protocol gives good adaptation and performance.