Stable And Efficient Improvement Of AODV Protocol In Ad Hoc Network

Ad Hoc network is a special wireless network which can self-organize without the infrastructure such as base stations. It is the nature of the distributed multi-hop wireless network and its communication depends on mobile terminals with a routing function. The characteristic that it is not easy to build the networks in certain environments will affect the comprehensive and systematic communication, so Ad Hoc network can be widely promoted and applied in view of the self-organizing capacity of mobile terminals.The core issue of communication is that the information can be transmitted along the correct path, and it needs to be resolved by routing protocols. A lot of routing protocols which are used specially in Ad Hoc network have been developed for a range of features of the strong mobility, the fast topology changes and the limited node energy in Ad Hoc network. Among these protocols, AODV as a on-demand routing protocol, its overall performance is excellent, so it has been widely used. The minimum hop routing selection algorithm is too simple to gain the ideal route cost and end-to-end delay performances, therefore it will not be able to achieve stable and efficient communication.To overcome the drawbacks of the traditional AODV protocol and make the communication more stable and efficient, this paper presents an improved AODV routing algorithm in Ad Hoc network based on piggyback mechanism and weighted neighbor stability. First of all, for reducing route cost, a piggyback mechanism is introduced into the AODV protocol. Generally, the use of piggyback mechanism can greatly reduce route cost and delay but may decrease delivery ratio slightly. For the improvement of delivery performance, an improved NCR-AODV protocol is then proposed based on our new idea of the stability of neighbor nodes, i.e., weighted neighbor change ratio (NCR), which means jointly considering NCRs both at the current time and historical times. Through NS2 simulation, the results show that, our proposed NCR-AODV can greatly enhance the network performance in terms of route cost and delivery ratio.