The Routing Protocol Research Of Cognitive Wireless Ad Hoc Network

Ad hoc network is a kind of special wireless network,which can be stuctured provisionally without the infrastructure. Every node in the network can act as a host and router. Ad Hoc network has many practical applications in military field and civil field as its advantage of self-organizing,invulnerability and without requiring fixed infrastructure. So Ad hoc network is paid more and more attention by the people. As one of the key technologies of the Ad Hoc network,Routing protocol has become a heated and major problem.This paper introduces the development status, characteristics and definition of the Ad Hoc network. This paper analyzes the characteristics of its various routing protocols, and are compared.Then AODV routing protocol whic is commonly used for Ad hoc network is conducted in-depth research and analysis of simulation performance in different topologies. The simulation results show that the AODV protocol was prone to be congested when it through a large amount of network data.Inorder to reduce the congestion and the time to find the route in AODV protocol, CA-AODV protocol is proposed as an ant colony algorithm with cognitive ability. The algorithm has been improved on the ant colony algorithm which is based on the characteristics of the cognitive network. The algorithm improves routing search capabilities by using probability routing and diffusion of pheromone. The algorithm makes a pathfinding ants have the ability of aware network state. The ants can predict the congestion status of the link,so that it can find a new route quicklyjn order to disperse traffic and relieve the congestion state. By comparing between AODV protocol and CAAODV protocol on OPNET simulation platform,it can verify the superiority of the CA AODV algorithm.