A Search For DA-STDMA In MANET Based On Directional Antenna

Mobile Ad-hoc Network is a temporary network with no center, which composed of mobile terminal nodes with wireless communication device. Because of its unique features of no network facilities, rapid deployment, survivability and strong, it has become the preferred technology in digital battlefield communication, as well as the core technology of tactical internet.The core content of Mobile Ad-hoc Network technology is access control protocol. At present, the access control protocol of most military wireless communication system is time division multiple access (TDMA) protocol based on Omni directional antenna. However, the use of Omni directional antenna brought much communication interference, and also reduces the single hop communication distance between two nodes. Compared to the Omni directional antenna, Directional antenna, which has a certain direction in the radiation direction, increases the signal coverage area, increases the radiation power, greatly improves the spatial reuse rate, increases the channel capacity, and has strong anti-interference ability. In this paper, we effectively combined the advantages between the TDMA protocol and the Directional antenna technology, and design the TDMA protocol based on Directional antenna——the DA-TDMA protocol.In this paper, we make a research in DA-STDMA protocol, including the detail design of framework and its operation logic. The DA-STDMA node is required to equip with both omni-directional antenna pattern and directional antenna pattern, which controlled by a switch. Every frame is divided into three parts:Neighbor Discovery slot(ND slot), Semi-Permanent slot(SP slot) and Demand-Assigned slot(DA slot), each part has a corresponding operating mechanism. The neighbor discovery mechanism in ND slot makes the nodes in the network able to obtain the dynamic network topology information, which provides strong support for the network resource scheduling algorithm. In this paper, we introduce the time slot resource scheduling mechanism in SP slot and DA slot, which can not only increase the reuse ratio of the time slot, but also effectively deal with the dynamic changes of the network to ensure the reliable and fast transmission of the data.Finally, this paper models the DA-STDMA protocol with OPNET. Collect the results of the simulation to compare the performance of the DA-STDMA protocol with the traditional802.11protocol. This paper also uses C++to model the static allocation algorithm of DA-STDMA protocol. All the results proof that the DA-STDMA protocol has great advantages.