Based On Two-hop Neighbors Aodv Routing Local Repair Improvements

Mobile Ad Hoc Networks is no central entity, self-organization and self-healing network where various network nodes can communicate with each other, exchange data to achieve the share of information and services through wireless links. Network nodes can be dynamically, casual manner, frequently entering and leaving the network, without the need for prior notification, but would not influence the communication of other nodes.The two essential properties of Ad Hoc networks are the mobility and wireless communication. Due to Ad Hoc Networks' mobility and link instability how to reduce the data packet loss caused by the link interruption and how to quickly recover the failure of link owing to communication disruption is a significant issue in the research of network communication.This dissertation introduces the neighbor detection mechanism and analyzes the delay effect of the HELLO mechanism that may cause the obsolete or awry neighbors information. In order to control the outdated neighbor information, the neighbor trust which is used to select the more reliable neighbor information is proposed in this article. With the design and implement of the two jump neighbors topology based on the neighbors trust, each node can assessment the link quality and reliability of neighbor information in two jump topology.This dissertation introduces the local route repair mechanism of the typical routing protocols in Ad Hoc wireless network and analyzes the pros and cons of the local route repair mechanism of several routing protocols after which it focus on the disadvantages of the local route repair mechanism of the AODV routing protocol. The article outlines the instability of link and the difficulty of data rescue with the routing repair mechanise in AODV.In order to solve the existing problems of the local route repair mechanism of the AODV routing protocol, the new AODV local route repair algorithm——AODV-NDA (Neighbors Detection and Assessment) is proposed in this dissertation. Aiming at the instability of the routing local repair in AODV and based on the process of caching data in the upstream nodes, assessing of the quality of link in the downstream nodes, rescuing data and recovering data by back jump node, this algorithm has solved the problems of searching for reliable link to recover communication and reducing the lost of packages. Three advantages lie in the algorithm. Firstly, it uses the programme of assessment of the downstream link's quality and local repair initiated by the back jump node to avoid repairing routing in instability regional. Secondly, It adopts the programme of the data cache in the upstream nodes to reduce data packets that need to be rescued. Finally, the algorithm uses the programme of data rescue to achieve the non-interactive data rescue.This paper has realized the simulation of the AODV-NDA within the NS2 system simulation platform.Under different network environments, with the comparison of the performance of the AODV-NDA routing algorithm and the traditional local route repair mechanism in AODV, the article has verified the feasibility of the algorithm. Finally, based on rigorous data analysis, it concludes that the AODV-NDA algorithm plays better performance in the heavy load wireless network.