A Survey on Credit-Based Incentive Schemes in Delay Tolerant Network

A Delay Tolerant Network is a network of regional networks having characteristics like long or variable delay, intermittent connectivity, asymmetric data rate and high error rates. Due to these characteristics, DTN is designed to operate in wide-ranging applications where end to end connectivity is not always guaranteed like space communication and inter-planetary communication. DTN uses the store-carry-and-forward mechanism to relay bundles from source node to the destination node. In DTN bundles are routed to destination node with the hypothesis that each intermediate node is willing to relay incoming bundle to next hop. In real time application, DTN nodes are controlled and handled by rational entities such as organisation so DTN nodes will behave selfishly and violates the hypothesis. To address the problem of selfish behaviour of node in DTN, various credit based incentive schemes are proposed with suggestion of some incentive should be offered to intermediate nodes so that they will participate in bundle relaying and nodes will not behave selfishly. In this paper, we surveyed and compared existing credit based incentive mechanisms. Also, stated some open research issues in DTN at last in conclusion.