The Study Of The Routing Protocol For Mobile Ad Hoc Networks

Mobile Ad Hoc networks are self-organized dynamic multi-hop networks in which nodes arefree to move and can be used as both hosts and routers. In such networks, network topologychanges frequently and unpredictably due to the arbitrary mobility of the nodes. Hence, how toefficiently build routes among nodes is an increasing important core issue for mobile Ad Hocnetworks. The design of routing protocols for mobile Ad Hoc networks has being a popular anddifficult issue since the birth of such networks. With the rapid development of the technology, thegoal of designing routing protocol is no longer for the basic functions, but for improving the qualityof services and reducing network energy consumption. It is a tough task to design a routing protocolwith low-latency, low-overhead, high throughput and low packet loss rate, let alone this routingprotocol is energy-efficient.In mobile Ad Hoc networks, channel contention and packet collision can seriously affect theperformance of routing protocols. By respectively predicting the durations of the contention andcollision at every hop along the route, this thesis proposes a minimum interference cross-layerrouting protocol called MI-CLR based on random waypoint model. The new protocol classifies theinterference in the network into two types; the first type of interference can only affect channelcontention, while the other affects both channel contention and packet collision. Via taking the twotypes of interference together into account, a new routing metric is peoposed to build routes whichguarantees that the established routes will not break frequently while having the minimuminterference. Simulation results show that MI-CLR can significantly improve the networkperformance such as the throughput, the packet loss ratio, the routing overhead and the averageend-to-end delay.The traditional hop-based routing protocols for mobile Ad Hoc networks cannot reflect theinterference strength and communication load degree around each node. This thesis puts forward aninterference aware routing protocol called IA-CLR for mobile Ad Hoc networks based on the IEEE802.11medium access layer. By defining the node’s sending and receiving capabilities, IA-CLR canindicate the interference strength of the link in a real and comprehensive way. Further more, inorder to choose the route with minimum bottleneck link interference, a new routing metric isproposed by combining the MAC layer and the network layer for cross layer design. Simulation results show that IA-CLR can significantly improve the performances of network such as theaverage end-to-end delay, the packets loss ratio and the throughput.Reducing the network energy consumption and increasing the network lifetime are the twomain objectives for mobile Ad Hoc networks. This thesis proposes an energy-aware routingprotocol that simultaneously meets above two objectives. It first presents RECI (Route EnergyComprehensive Index) as the new routing metric, then chooses the path with both minimum hopsand maximum RECI value as the route in route discovery phase, and finally takes some measures toprotect the source nodes and the sink nodes from being overused when their energies are low so asto prolong the life of the corresponding data flow. Simulation results show that the proposedprotocol can significantly reduce the energy consumption and extend the network lifetime whileimprove the average end-to-end delay compared with other protocols.