Ad Hoc Wireless Access Layer Research

Ad Hoc network is a self-organizing wireless communication networks, it is not like the traditional wireless network that requires a wireless access control node, or dependent on fixed wireless infrastructure. In Ad Hoc network, a relay nodes for the multi-hop data transmission, each node is not only as a communication terminal will also be used for network routing relay. Ad Hoc networks with so many distinctive characters that other networks do not have, while the MAC protocol, namely the medium access protocol is a key part of the distinctive characteristics Ad Hoc network,so the study for Ad Hoc Networks MAC protocol is essential.Based on the analysis of the characteristics of the Ad Hoc Networks and today’s widely used MAC layer protocol for Ad Hoc Networks-802.11DCF, this paper presents a dynamic allocation of multi-channel MAC protocol,through re-divided the wireless channel into many parallel subchannels, that one for dedicated control channel, to come ture the separation of control and transmission channels,.then avoid network hidden node and exposed node’s effects.To make an appointment by way of the channel, the node order from disorder into contract bidding, contract to reduce conflicts between nodes. Mathematical model can be drawn by the protocol can significantly improve network throughput.At the same time based on the multi-channel MAC protocol dynamically allocated,this paper proposes a multi-access protocol with collision avoidance slot cycle, divided by the number of time slots within the channel the way, making the access nodes in an orderly manner, and control every slots’transmission probability so that part of the time slot has been reached conflict-free contract, and finally through the slot of the cycle between nodes solved the problem of access to equity. Multi-slot approach can significantly enhance the efficiency of wireless channel and thus increase the access network throughput.