Research On The MAC Protocol Based On The DBTMA In Wireless Ad Hoc Networks

The medium control access protocol is used to decide how to share the finite channel resource. Firstly the protocol is designed to guarantee the fairness, and all the nodes share the channel fairly . and secondly the efficiency of channel utilization should be high comparatively, and insure that the limited frequency resource should be made use of adequately. In Ad Hoc network the hidden and exposed terminal problems have an severe impact on the performance of the MAC protocol, so some research based on the Dual Busy Tone Multiple Access (DBTMA) scheme has been presented to sovle the hidden and exposed problems, and intend to have high channe utilization efficiency, low delay and better fairness correspondingly, which are the focus of this paper.Firstly this paper introduces the hidden and exposed problems existing in the wireless channel, and gives an analysis on the problems and challenge which the research of the MAC protocols is in face of. Discussion and contrast of the means to solve the hidden and exposed problems have been made. The strength and the weakness of each method and their applicable occasions are pointed out, which are the foundation of the application.Secondly , a thorough research of the busy tone detection scheme has been presented based on the detailed discussion of RTS/CTS scheme of the single and multi- channel, and DBTMA protocol has been discussed emphatically. The performance of the DBTMA protocol is analysed, and improved opinions in two aspects are summarized as follow. First, aimed at the fairness issue, an improvement of the busy tone detection scheme has been presented. This paper attempts to get rid of the transmission busy tone to guarantee the fairness of the protocol, meanwhile reducing the complexity and shortening the delay of the protocol. The scheme could improve the exposed-terminal problem caused by the transmission busy tone. The result of simulation shows that the scheme improves the equality of the protocol with slight performance degradation. Second, an improvement of the dual channel has been...