The Research Of Key Technologies On Ad Hoc Access Network

With the continuous developments of Ad Hoc networks in recent years, studying on the Ad Hoc access network becomes one of the hot topics. Recently, researchers generally expand Ad Hoc unicast routing protocols to achieve the Ad Hoc access networks. Because the multicast routing technology can take advantages of wireless channel resources and the broadcast property of wireless communication, and users of Ad Hoc network often need to form collaborative working groups to cooperate, the multicast technology has great potentials in Ad Hoc access network.Ad Hoc nodes can access to other networks only with gateways. Generally, there are a number of access gateways in the Ad Hoc access network, so how to select the best gateway becomes the key problem of the study. Some of the existing gateway selection algorithms still have many problems, such as frequent gateway switching, load imbalance and so on. It is necessary to make optimizations and improvements to solve these problems.The mainly works in this paper are as follows:1. At first, this paper introduces the Ad Hoc network and Ad Hoc access network, and indicates that extending Ad Hoc multicast routing protocols is an effective way to achieve the Ad Hoc access networks. Then a novel scheme to achieve Ad Hoc access network by extending the MAODV protocol is proposed.2. Under the study of Jelger gateway selection algorithm, this paper points out its shortcomings such as frequent gateway switching and gateway loads imbalance. By the comprehensive consideration of hops and gateway loads, this paper proposes an improved algorithm. The new algorithm can effectively solve the above problems and improve the performance of the access network.3. Using OPNET simulation software, this paper constructs the Ad Hoc node models based on MAODV, and extends the MAODV protocol to achieve a simple Ad Hoc access network. Then it combines both the original Jelger algorithm and the improved algorithm with the extended MAODV protocol, and makes the simulation and analysis at last. The results prove the feasibility of the algorithm combined with MAODV and the efficiency of the improvement algorithm.