The Research On Data Dissemination Scheme And Incentive Scheme In Opportunistic Networks

The rapid development and popularization of intelligent devices promotes the rapid development of wireless ad hoc network.Opportunistic network uses the chance encountering between network nodes to achieve communication of not-all-pass network.The opportunistic network uses the "store-carry-forward" approach to communicate.As a new networking,it breaks through the traditional network for the delay and rate limiting.The opportunistic network has great application potential in many areas.Most studies for the Opportunistic network focuses on the routing mechanisms currently not on data distribution mechanisms.The data distribution mechanisms of opportunistic network can effectively solve the network data accessing and forwarding rationality.There is also node selfishness phenomenon in opportunistic network.The selfish nodes lead to 'free rider" and "tragedy of the commons" issues in networks.So the selfish behavior seriously affects the overall performance of opportunistic network.In this paper,on the basis of research on the key technology of opportunistic network,we put forward the data distribution mechanism based on node degree centricity.The mechanism's goal is to use less relay nodes to distribute data to more nodes which interest in the data.In the relay node selection strategy,this mechanism will calculate data distribution capabilities across all adjacent nodes and update the nodes'degree centricity.Then choose the node with high degree centricity as the relay node.At the same time,it comes up with measuring the surplus value of node to prevent the excessive consumption of resources and energy.The data distribution policy would not affect the delivery rate of the data to save network resource.And in the limited network resources,this mechanism reflects better data delivery performance.Even with effectively data distribution mechanisms,but selfish nodes in the network will seriously affect the data delivery in opportunistic network.For response selfish phenomenon in the network,this paper proposes a community-based reputation incentive scheme.This incentive scheme fully considers community property of the node and then achieves selfish discrimination based on reputation value of the node.The incentive scheme allows nodes to save the credentials of forwarding credentials as a reputation credentials for verification.This incentive scheme proposes altruistic function as a calculation factor of kicking off malicious nodes in network.The incentive scheme takes full account of the social attributes of nodes and using different methods of calculation reputation based on whether the encountering nodes belong to the same community:intra-community reputation calculation and inter-community reputation calculation which reflects the fairness of reputation calculation.Due to the special nature of relay nodes in different communities,this incentive scheme uses reward policy for high reputation node in different communities and also uses prison punishment policy for selfish nodes in different communities.This incentive scheme can encourage selfish nodes participating in data forwarding effectively and ensure the fairness of incentives.The design and implementation of data distribution and incentive mechanisms can effectively improve network performance of opportunistic networks.