Research On An Improved AODV Protocol Based On Route Breaks Prediction

AODV routing protocol, namely the Ad Hoc On-demand Distance Vector routing protocol, is one of the widely used on-demand routing protocols in the mobile Ad Hoc network. AODV routing protocol has some advantages, besides its simple algorithm, the packet in it doesn’t need carry the full routing information. In this protocol, the number of hops is treated as the measure of the routing quality, although the path with less hops can get a shorter data packet transfer delay, it also increases the probability of link breaks, and brings the problem of edge effect, which means that the adjacent nodes in the active routing are located on the edge of the place where they communicate with each other, and the danger of link break is prone to happen. While, the edge effect problem can bring harms, which can often influence the stability of the link, or increase the time delay, and what’s worse, can lead to the loss of data packets.This paper is focus on the problem of edge effect in AODV protocol, and on the basis of the further study of AODV routing protocol, a new algorithm named ARB-AODV is proposed, which improve and optimize the AODV algorithm. The algorithm can repair the link with low overhead before it breaks, specific to take the following measures:(1) Predict the possibility of link breaks. First, set the threshold of nodes’ received power, then compare the real received power and the threshold to determine whether the two nodes are on the very edge of each other’s communication rage.(2) Add the relative stability information to the node’s neighbor information. The aim is to indicate the relative stability of the adjacent node and the node itself.(3) Find the intermediate node of high stability through comparing the neighbor information of two nodes and put it into the link which is likely to break. The objective is to enhance the stability of the link and try the best effort to avoid the route breaks.The simulation experiment on AODV and ARB-AODV was made by using the NS-2 software, and the simulation set different maximum speeds of the nodes to compare and analysis the average end-to-end delay of data packet, the overhead of routing and the packet delivery ratio of the two protocols, the results show that the higher of the maximum speed of the nodes, performance of the three aspects of ARB-AODV is better than AODV protocol, and improve the stability of network effectively.