Research And Embedded Realization Of Backup Routing Protocol In Ad Hoc Network

A mobile ad hoc network(MANET) is a kind of multi-hop, self-organizing wireless network. With the widely use of 4G and Internet of things, MANET has been recognized as the part of the future heterogeneous network. High dynamic characteristics of Ad Hoc network leads to frequent changes of network topology. Therefore design and optimization of routing protocol is the focus of Ad Hoc network research field.The paper conducts a deep research on AODV routing protocol and analyses the problem of the inadequate use of routing controlling messages in routing discovery process. By using backup routing, the paper presents an improvement scheme of AODV and transplants the improved AODV routing protocol into the ARM embedded processor.In the AODV routing discovery process, the source node only handles the RREP message which has the larger destination sequence number and discards the other potential valid RREP. The original routing scheme can not make full use of the routing controlling messages. The paper presents an improved scheme called AODV-SNB based on source node backup routing. The new scheme establishes the main route and the backup route with the use of the RREP messages. When the main route is invalid, the last hop node of the broken link will transmit data on the backup route. Only the backup route fails, the route repairing process will work. Using NS2 Network Simulator, the experimental results demonstrate that the improved protocol has better results than the original protocol under the high payloads.Based on improved AODV protocol and ARM Cortex-M3 embedded processor, the paper takes the broadcast characteristic of the wireless radio signal and the characteristic of ARM processor into consideration and designs the embedded AODV backup routing protocol, AODV-EBR. In order to make the AODV backup routing protocol work well in the embedded system, the paper designs the simplified packet format, the link state sensing mechanism and the backup routing switch mechanism. The experimental phenomena show that the system can realize the fundamental functions of the embedded AODV backup routing protocol.