Researsh On Free Rider Suppression And Resource Balancing In Mobile P2P Network

Mobile P2P technology provides new opportunities on sharing resources and takes full advantage of the potential resources and storage capacity in the Internet.Resource sharing is an important way for the communication among mobile nodes.However,nodes in mobile networks maybe selfish.They get resources from the networks as many as possible,instead of contributing resources.This behavior is known as free riding which is becoming increasingly serious.Such selfish behavior not only depresses well-behaving nodes,also decreases the available resources in the mobile networks.Additionally,resources in mobile P2P networks raise the problem of imbalance between supply and demand.When the number of available resources is much smaller than requested ones,nodes have to stand in line waiting for resources,which reduces the efficiency of resource interaction,and even leads to network congestion.In order to alleviate the problems above,resource interaction system based on mobile P2P network needs an effective incentive mechanism to suppress the selfish behavior.And the balance of resources' supply and demand relations should also be guaranteed.This paper studies the selfish behavior of nodes and the relation of resources' supply and demand,and presents free rider suppression and resource balancing mechanism.Firstly,considering the characteristics of the resource interaction in mobile P2P network,we establish and analysis the game-theoretic based resource interaction model.Then,according to the characteristics of mobile P2P network structure and node movement,this paper presents a cooperative node selection algorithm based on the prediction of mobility and stability of communication link.The algorithm predicts the motion of nodes,calculates the stability of each optional communication link,and choose the optimal cooperation node with better communication link stability.On the basis of resources interaction model,the paper proposes a selfish node suppression and resource balancing mechanism.The selfish node suppression mechanism contains reputation-based encourage strategy and service restriction based punishment strategy.Reputation-based encourage strategy is to control the profit of the contribute node in one resource interaction via its historical contribution coefficient.The more resource it has contributed,the more profit it get.The service restriction based punishment strategy is used to punish the selfish nodes who refuse to cooperate by limiting their participation in the follow-up resource interaction.Considering the dynamic nature of resource requirements,the resource balancing mechanism presents the dynamic price function of resource.Combined with the benefits of nodes,the strategy can ensure the real-time dynamic balance of resource supply and demand relation by self-regulating mechanism of the market.