Directional Antennal Control Method Based On The Neighbors Awareness In Ad Hoc Network

Ad Hoc network is a communication network, it's completely different from the traditional network. The devices in the Ad Hoc network can be used as transceiver and router, so multi-hop communication can be achieved by itself. As the Ad Hoc network do not require a fixed infrastructure, a high degree of flexibility and survivability capabilities, can be widely used in military operations, emergency search and rescue as well as office meetings. In the wireless Ad Hoc networks, all devices using the same frequency, there may be a number of devices access channel at the same time, resulting in collision. To solve this problem, we need media access control (MAC) protocol to coordinate the devices, so that it can be efficient, orderly and equitable use of the media.Ad Hoc network have many MAC protocol, which can generally be divided into based on the first invitation to initiate communications, channel number, as well as whether to use categories of directional antenna. 802.11 DCF protocol is the most basic MAC protocol, a lot of MAC protocol is improvement in it. The traditional protocol use of the antenna is omni antenna, this antenna structure is simple and easy to implement. Directional antenna can be as a result of higher gain antennas, and to improve channel utilization of space and so on, in recent years attracted more and more attention, a number of directional antenna MAC protocol appear.In this paper, the major work done by the following:1. This paper is in-depth analysis of the existing MAC protocol on the basis of summing up the advantages and disadvantages of these agreements, resulted in the existing MAC protocol can not complete solve the problem of Ad Hoc Network. DMAC protocol is the basic of this paper's new MAC protocol--directional antenna control method based on the neighbors' awareness in Ad Hoc network, therefore, it presented a very detailed.2. The significance of this study is that using the MAC protocol proposed in this paper to improve the channel utilization of space. If more nodes want to use the channel to communication, the channel is very busy; the index of local channel will be higher. So we make the pulse width narrower, it can leave more space channel for the others nodes which want to use it. If fewer nodes want to use the wireless channel, the index of local channel is small, and then the pulse width should be wider, as the mobile node it can minimize the packet loss. The simulation results show that agreement NEMA-DMAC throughput, jitter and delay performance are superior to the existing MAC protocol.