Three Riding Problems In Peer-to-Peer Network Research

As the result of the growing development of computer technology, people depend On computer more and more,However, the progress of server is much slower than the progress of personal computer. Meanwhile, network technology is applied worldwide and the society gets great benefit from Internet.The best method to deal with the situation is P2P technology.After many years development P2P technology becomes more and more mature,and there are a lot of successful P2P based applications on the Internet . And the architecture of P2P network itself is also evolving.However, current architectures of P2P network, whether constructed or not, are based on an assumption, which every node can share resources kindly and maximally.But a node always wants to maximize its network utility.Because current P2P networks have not considered the reality,there are two problems produced.One is that there are plenty of"Free-Riding"users in many P2P systems.Another is that the phenomena of homogenization become very severe and users can't get useful resources from the networks.This thesis focuses on the"Free-Riding"problem and designs a incentive mechanism to P2P systems.The main details are as follows:1. This thesis introduces the history and recent researches of P2P technology and its application on different area. We analyze the problem of free-riding,which is more and more serious and has great impact on P2P system.Also we discuss on the importance to solving the problem of free-riding on P2P system.2. We analyze and compare the existing micro-payment model,direct reciprocity model,reputation-based mechanisms and punishment mechanism.At the same time,we discuss their advantages and disadvantages.3. Put forward a kind of network grading incentive mechanism GAIM, according to the number of free-riding nodes the network is divided into three levels, in different levels use different connection management agreement; The node of the utility function is divided into two parts, one part representative the node can offer service ability, another segments representing the node can enjoy service ability. Meanwhile user node executes based on bandwidth allocation strategy, which enables nodes utility, the higher the income the better service. The online time, extend hitchhiking incentive for its network to do more contribution.4. Through the NS simulation, the experimental results show that GAIM is incentive,under the same condition as the maximum downloading bandwidth, the node which makes greater contributions to the system acquires bigger downloading bandwidth, on the contrary, the less downloading bandwidth.In addition, the mechanism uses the bandwidth as much as possible. Then,the peer-to-peer network can provide service differentiation to every node by its contribution the network.The node which wants to get more service should provide more resource and forwards more transmitting messages to the system.This method incentives every node to make contribution to the system and improves the system efficiency hardly.