The Research Of Routing Protocols Based On Ad Hoc Networks

Self-orgnizing network is also called Ad Hoc network,which is a particular kind of wireless communication network.Ad Hoc network is self-orgnized without center controller and with multi-hops.These characteristics ensures that Ad Hoc network,especially the router layer of the network, is likely to be attacked.What's more,nodes in the network has limited energy,algorithms that needs a lot computation will consume the energy of the nodes greatly,this will lead to the increase of network route overhead, which will affact the lifespan of the network.Therefore,how to prevent the generation of route overhead and at the same time to assure the security of the network is to be solved in the routing design of the Ad Hoc.The proactive routing protocols of the Ad Hoc network usually use flooding to initiate route discovery process and to transfer data packets.That will cause some problems, especially in high density networks.The flooding will produce a lot of redundant packets which will exhaust the limited resourse of the Ad Hoc network.Redundant packets will cause bandwidth contention,packet collision,channel collision and so on,this will reduce the packet delivery ratio and increase the average packet delay.Therefore,protocols that use blind flooding will exert a great impact on network.To design a routing protocol which can effectively reduce the flooding information is one of the questions that must be taken into account when designing the Ad Hoc routing protocols.Main contents and innovations in this paper are as follows:(1)A new routing protocol,GT-AODV,based on a non-coorperate and non-zero sum game theory, is proposed. The game theory model is a two-layer game consisting of the Ad Hoc network and the malicious nodes.Theoretical analysis showed that Nash Equilibrium point existed in the game,namely there is a dominanted strategy for both sides of the players in the game.GT-AODV chooses a route to transmit data according to dominant strategy. The selected route is least likely to be attacked by the malicious nodes, and will cost least overhead for it to be defended.Meanwhile IDS is adopted to defend the attack of the malicious nodes, each node is bonded with an IDS to detect the behavior of the malicious nodes and to take measures to stop the attack. Simulation results shows that GT-AODV inherits the merits of the effective route discovery and route maitainence of AODV, it greatly reduces the route overhead and packet loss rato while improving the network performance.(2)The massive redundancy packets produced in Ad Hoc networks will consume much bandwidth, power and so on, this may lead to bandwidth contention, packet collision, packet dropping ,delay and so on.To fix these problems,a routing protocol called FSG is proposed.This algorithm regard the nodes in the network as players of the game. And nodes adopt mixed strategy to caculate the probability of forwarding when receiving the flooding packets from his neighbor nodes. FSG made some modifications on Hello message. Simulation results proved that FSG-AODV can retain the connecitivity of network and can limit the number of nodes participating in the routing discovery process, this effectively reduce the flooding pakets.In high-density network,FSG-AODV could improve network connectivity,increase the packet delivery ratio and reduce the average delay.