Wireless Networking Multi-path Routing Algorithms,

Ad hoc network consists of a set of mobile nodes with wireless communication transceivers.It's a multi-hop temporary network without centralized control or fixed network infrastructure.And each node in the network can move freely.In such an environment,it may be necessary for one mobile host to seek the aid of others in forwarding a packet to its destination,due to the limited propagation range of each mobile host's wireless transmissions.Thus each node acts as router as well as a terminal. With development of ad hoc network changing from military to civilian use,more and more applications are jointed into mobile ad hoc network,such as:disaster recovery, crowd control,search and rescue,etc.In many ways,Ad Hoc network is better than many other networks.But,nodes Varese able to move,routing may be lost at any time.Router losing makes the routing unreliable and instable.To overcome of these difficulties becomes the key of ad hoc network study.Multi—path route protocol computes and maintains alternative Multi—paths in routing finding process.Multi—path has better performance than single path routing protocol whenever in delay,error tolerance reliability.Any more,Multi—path routing protocol is used in load balance of ad hoc network too.So Multi—path routing protocol is focused in ad hoc network.Ad hoc network is introduced in chapter one,including the definition, characteristic,application fields and key technologies of ad hoc network.The analysis of research actuality of network route technology is conducted in chapter two.In chapter three,we introduce the backgrounds of the Multi—path routing protocol.Then some existing routing protocols are compared and researched in features and performance.A new improved AODV Multi—path routing algorithm,named CLLB—AODV, is addressed in chapter four.The traffic of MAC layer to estimate node's load and choose paths according to path's load.In chapter five,we introduce an AODV-based node-disjoint distance-vector multi-path routing protocol——AODV—NDMR, that establishes and maintains multiple node-disjoint paths for data transmissions.In chapter six,we introduce simulation system.We use OPNET to simulate the protocols of CLLB—AODV,AODV—NDMR and AODV.The simulation results have confirmed that CLLB—AODV and AODV—NDMR routing protocol have a better performance in data packet delivery ratio,end-to-end delay and throughput compared with the routing AODV protocol.