Research And Implementation Of AODV-I Protocol In Ad Hoc Network

Ad Hoc network is a multi-hop, autonomous, acentric system, which consists of mobile terminal with wireless transceiver, and it can be deployed rapidly without relying on any pre-established infrastructure, so it is quite suitable to some special field such as battlefield, disaster relief, personal communication and wireless sensor network etc. The traditional Internet routing protocols can't meet the demand of frequent topology changes in Ad Hoc network, so the routing protocols become an important research issue.This paper conducts a deep research on AODV protocol and discusses two problems in its route discovery process:lacking congestion control on RREQ message sending by the requesting node and no guarantee mechanism of RREP message returning to the requesting node. This paper proposes an improvement protocol AODV-I based on the investigation above, in which congestion control in RREQ message transmitting process is adopted and route repair mechanism in RREP message forwarding process is utilized. The AODV-I can choose the relatively idle node automatically when establishing a new route, and also make sure that the RREP message returns to the requesting node under the circumstance of route fault, thus avoiding another unnecessary route request. With these improvements to AODV protocol, it is possible to reduce the rate of packet loss as well as end-to-end delay and increase network resource utilization.This paper introduces several typical routing protocols, and analyzes their advantages and disadvantages. Through the deep research on the AODV protocol, two problems in the routing discovery process are discussed and improved schemes are put forward. The improved schemes are implemented by modifying the code in NS. Finally, the result of emulation is analyzed to verify the feasibility of the scheme.