A Modified Ad Hoc Routing Protocol Based On Ant Colony Algorithm Research

Ad Hoc is a multi-hop, no-central, self-organized wireless network. It’s a typical dynamic self-adaptive network without changeless topology structure and central node. It is also called as multi-hop net because it usually routes in a "multi-hop" way. Ad Hoc network has characteristics of being quickly constructed, devices conveniently taken, strong flexibility. It is now widely used in public and military. But in recent research, when "hops" are considered as routing standard, quality of network can be easily neglected such as Signal-to-Noise, stability and security. Moreover, periodic routing information broadcast can also cause overmuch waste of bandwidth and battery.In Ad Hoc, ant colony technique can supply communication among nodes, as some applications need the cooperation between host computers. But in traditional static network, ant colony algorithm can’t adapt to Ad Hoc well, because the real-time change may destroy original forward structure and protocol doesn’t have an ability of fast recover. So ant colony algorithm plays an important part in the Ad Hoc research. Since there is disadvantage that ant colony algorithm can’t find multi-purposes in Ad Hoc, we propose a converse searching method. That is, when forward ants reach receiving node, system automatically copies several backtrack ants and they return. In addition, broadcast period and used frequency of nodes are added to the data in backtrack ants, in order to set different update period of different nodes instead of uniform broadcast update period. Simulation result shows that modified algorithm is better that original protocol in data delay, waste of bandwidth, the number of sent packets, and the convergence rate is heavily improved.The paper proposes a modified Ad Hoc routing protocol based on ant colony algorithm to improve protocol’s disadvantages using characteristic of algorithm. The steady data transmission gives a higher packet delivery rate, so that the number of data resend is reduced. Moreover, protocol reduces waste of bandwidth and consumption of battery power in order to prolong life of network. Then we choose NS2as simulation tool and show its structure, operating mechanism and wireless pipeline. In the end, the paper summarizes its content and prospects research of ant colony algorithm in the future.