Research On Congestion Control And Routing Protocol In Opportunistic Networks

Opportunistic network is a new kind of Mobile Ad hoc Networks(MANET), its character is thelinks between nodes are frequently broken. So these protocols in the MANET can’t run in theopportunistic network. The nodes adopt”cache-move-forward” mode to communication, this islikely to cause the node congestion. So, research on routing protocols and congestion control arealways the hot investigation in Opportunistic Network. In this paper, we firstly analysis the routingstrategies and congestion control strategies. Afterwards, we propose Domain-Epidemic Spray andForward Routing algorithm, congestion control algorithm comprehensive delete messages andtransfer packets.Domain-Epidemic Spray and Forward Routing algorithm in Opportunistic Network is proposedin the paper. The algorithm integrates redundancy and encounter prediction strategy. According tothe probability of encounters between nodes, the nodes are divided into different domains. TheSpray and Forward strategy is used between domains and the epidemic strategy is used to forwardmessages within a domain. Using the message confirmation mechanism and a list which is used torecord the messages that have arrived the destination, the new algorithm can effectively reduce theredundant messages. Simulation results show our algorithm can effectively improve the messagearrival rate and reduce the end-to-end delay to some extent.A congestion control algorithm comprehensive delete messages and transfer packets is proposedin the paper. According to the forwarding probability and the TTL of each message, the congestednode calculates the stores value of the message. The congested node delete the message which hasthe minimum stores value. The congested node transfers the message which has the minimumforwarding probability. Neighboring nodes calculate the received value of the message that has beentransferred based on the forwarding probability and their free buffer size. The congested nodetransfers the message to the neighboring node which have the maximum received value. If thetransfer fails, the massage will be deleted. The algorithm is more targeted to delete messages andwhile using the strategy of transfer message. The algorithm can significantly improved messagearrival rate and reduce the delay to some extent.