Research On Opportunistic Network Routing And Incentive Strategy Using Node And Message Attributes

Opportunistic network is a kind of mobile ad hoc network which has the characteristics of general tolerance delay network.It forms a unique communication mode of "store carry forward".The message delivery rate is low,but overhead is great.The network performance is degraded due to the fact that the nodes themselves are constrained by their own resources,which will refuse to delivery messages for other nodes.To improve network performance,we propose a routing protocol based on message value and incentive strategy based on the overdrawn virtual currency mechanism based on the analysis of the classic opportunistic network routing protocol and incentive strategy.The key to the question of opportunistic network routing protocol is how to choose forwarding nodes.The classical probabilistic routing protocol using history of encounters and transitivity calculates the probability of nodes only according to whether the nodes met in a period of time,which does not use encounter history information of the nodes effectively.Opportunistic network routing protocol based on message value(PBMV)makes use of the encounter interval to estimate encounter probability.Then selects the retransmission nodes exactly base on encounter probability.This article also defines a message value model,which calculates the value of each message in the transmission queue.Message value determines transmission order,which will reduce meaningless transmission.The simulation results show that compared with other opportunistic network routing protocols,the message delivery rate increase by at least 9.91%,the network overhead is decreased by 44.94% in average,the average forwarding number is decreased by 8.99% in average.Due to the limited resources of the opportunistic network,it is selfish to transmit messages without incentive strategy.Messages forwarding in classic incentive strategies of nodes based on virtual currency are abstracted into a transaction.The nodes should pay virtual currency to the forwarding node when forward messages.Nodes could earn virtual currency by forwarding messages for other nodes.However,most of the incentive strategies have the problem of virtual currency shortage and mendacious offer.With the purpose of solving the above problems,this article proposes a node incentive strategy based on the mechanism of overdraft virtual currency(NIS).The strategy has designed mechanism of overdraft virtual currency,which uses the ability of messages transmitting of a node as monetary overdraft guarantee to solve the problem of virtual currency shortage.The resource and wealth status are public in the trading mechanism of the strategy,if the message transaction cannot be completed once,the two sides will friendly bargain based on resource and wealth status to suppress the issue of mendacious offer.Simulation results verify the validity of the incentive mechanism of nodes and the overdrawn virtual currency mechanism.In the presence of malicious nodes,the network performance changes little,which verify that the strategy can suppress the issue of mendacious offer.