Research On The Routing Algorithm In Wireless Ad Hoc Networks Based On Ant Algorithm

A mobile ad-hoc network (MANET) is a collection of mobile nodes, which communicate over radio. These kinds of networks are very flexible, thus they do not require any existing infrastructure or central administration. Therefore, mobile ad-hoc networks are suitable for temporary communication links.Route acquisition is a key and difficult problem in Ad hoc networks, because the nodes always move frequently, which result in the network topology variety. A network routing protocol is the pivotal and core issue for realizing the Ad hoc communication. An effective routing protocol is important, which can shield upper layer application from the lower layer adverse factors and can supply a stable, reliable and high efficient communication. In this thesis, an improved multipath routing alogirthm called SAANIMRA (Scalable Ant-based Ad hoc Networks Intelligence Multipath Routing Algorithm) is presented based on the research on current routing algorithms.SAANIMRA is a multipath algorithm for routing in mobile Ad hoc networks based on ideas from the Bio-inspired Ant Colony Optimization framework. The algorithm consists of both reactive and proactive properties. In a reactive path setup phase, multipath is found between the source and the destination. The algorithm makes extensive use of ant-like mobile agents, which scan full paths between source and destination nodes. The algorithm takes the fairly distributing remaining energy across the network and the selected path's hops for routing into account, and the heuristic value about the moving way of the nodes, which are all factors of QoS. When selecting route, it reduces the possibility to follow adverse routes by avoiding passing through overload intermediate nodes. It makes the load spreading evenly, decreases traffic congestion, improves the throughout and so on. Meanwhile, due to the data load balance spreading, nodes' batteries energy is consumed evenly. Finally, it prolongs the lifespan and strengthens the survivability of the whole networks. Simulations are done in a few test scenarios using NS-2 and comparison is made between SAANIMRA and the state-of-the-art on-demand routing protocol AODV. According to the observed results, SAANIMRA outperforms AODV in packet delivery ratio, average end-to-end delay and packet delay jitter except forthe relative poor routing overhead. We want to point out that SAANIMRA has many more advantages than its routing overhead's disadvantages in large scale networks. SAANIMRA has better adaptivity and scalability.