Research On Opportunistic Network Routing And Congestion Control Strategy Based On Local Information

The appearance of lots of intelligent mobile devices equipped for short-range wireless communications boosts the fast rise of wireless ad hoc networks application. However, traditional routing communication model of mobile ad hoc network requires at least one path existing from source to destination nodes, which results in communication failure in these scenarios, where nodes form a disconnected network for most of the time because of nodal fast mobility, low network density, loss link, etc. Opportunistic networks utilize the communication opportunities arising from node movement, and adopt communications between nodes based on the “store-carry-forward” routing pattern. This is likely to result in lack of node resource. So, recently research on routing protocols and congestion control are the hot investigation in Opportunistic Network. In this paper, we firstly analysis the classical routing protocols and congestion control strategies. Then, we propose partial local information context spray and wait routing algorithm and a random early detection technique of the opportunistic network congestion control strategy considering node local information.Partial local information context Spray and Wait routing algorithm in Opportunistic Network is proposed in this paper. The algorithm adopts an adaptive method which can determine and approximate the number of copies based on the encountered node’s probability of successful message delivery. The metric of the probability of delivering message to the destination node and the time to carry the message by the carrier node are regarded as criteria for selecting one of the neighbor nodes as the forwarding node and to determine the number of message copies. The proposed algorithm operates in two phases of spray and wait. In spray phase, the node carrying the message forwards a fraction of the tokens to the encountered node; when the spray phase is finished, the wait phase starts. In this phase, the source node examines the possibility of delivering or not delivering the message to the destination. In case one of the neighbors of the node carrying the message is the destination, the forwarding process is finished.A random early detection technique of the opportunistic network congestion control strategy is proposed in this paper. Opportunistic network with node mobility, data extension, limited resources, etc. The relation between the relay node storage and network congestion is trade off. As a result, the network performance can be dramatically improved in limited resource scenarios by an effective congestion control strategy considering the node local partial information and random early detection technique. Both the mobile node storage and network congestion were taken into consideration, and then combined with the message’s value, a random early detection technique of the opportunistic network congestion control strategy was proposed, which could be used to reasonably allocate resource. Numerical results show that the message delivery ratio can be increased efficiently, and the overhead ratio and latency can also be optimized.