The Research Of Routing Protocol On Demand In Ad Hoc Network

Ad hoc network is one of whole distributed wireless communication network.Each of mobile terminal nodes in network can independent move, and play as routers and host. Transmitting data by the form of hop-by-hop, don't need infrastructure to support. Without center node, dynamic topology, hop-by-hop and temporary are some of Ad hoc network's characteristics. Due to these characteristics, the routing protocol of wireless network cannot be widely applied in network nowadays, the research of routing protocols become a hot point. Studying the existed routing protocol of AODV deeply, new A-AODV protocol is proposed which combine the Ant Colony Algorithm with AODV. Taking combination of mobility models as mobility model, and use the congestion processing mechanism in the aspect of routing maintenance.First of all, do a deep research of mobility models. Previous researches were mainly focus on the research of topology of the network or routing protocols. But if you want to reflect the reality condition, you need to combine the routing protocols with topology structure. Therefore, this paper combines these two methods according to the mobility model and these advantages and disadvantages. In the combination of mobility of model, the node distribution obeys evenly distributed basically, making up for Random Way Point Model and Random Direction Model's faults in mobile node way.Second, do a deep research of AODV, and analyze the performances of AODV. In the aspect of routing discovery, a new A-AODV method is proposed which combined the Ant Colony Algorithm with AODV. It uses ant to discover the routing, and the value of pheromone of ant colony as the selection criteria of path. Select the second-best path according to the certain probability. The delay and the throughout of the network can be improved.Then, in the aspect of routing maintenance, this paper mainly used the congestion processing mechanism and link prediction method to handle the problem of node congestion and link disconnect. Among them, congestion processing mechanism divides the node status into four stages. Different coping methods are used to deal with the node congestion circumstance of different stages. The link forecast method calculates the nodes firstly which can be disconnected, and notify the upstream nodes. It can maintain the connectivity and reduce the time delay of routing.At last, experiment with this method using the simulation software of OPNET. The experimental results show that our method can improve the time delay and network throughput than other AODV methods. Moreover, the feasibility of this method is validated.