Pi: A practical incentive protocol for delay tolerant networks

Abstract

Abstract-Delay Tolerant Networks (DTNs) are a class of networks characterized by lack of guaranteed connectivity, typically low frequency of encounters between DTN nodes and long propagation delays within the network. As a result, the message propagation process in DTNs follows a store-carryand-forward manner, and the in-transit bundle messages can be opportunistically routed towards the destinations through intermittent connections under the hypothesis that each individual DTN node is willing to help with forwarding. Unfortunately, there may exist some selfish nodes, especially in a cooperative network like DTN, and the presence of selfish DTN nodes could cause catastrophic damage to any well designed opportunistic routing scheme and jeopardize the whole network. In this paper, to address the selfishness problem in DTNs, we propose a practical incentive protocol, called Pi, such that when a source node sends a bundle message, it also attaches some incentive on the bundle, which is not only attractive but also fair to all participating DTN nodes. With the fair incentive, the selfish DTN nodes could be stimulated to help with forwarding bundles to achieve better packet delivery performance. In addition, the proposed Pi protocol can also thwart various attacks, which could be launched by selfish DTN nodes, such as free ride attack, layer removing and adding attacks. Extensive simulation results demonstrate the effectiveness of the proposed Pi protocol in terms of high delivery ratio and lower average delay.Index Terms-Delay tolerant networks, selfish node, fairness, practical incentive.

A routing defense mechanism using evolutionary game theory for Delay Tolerant Networks

“…The authors subsequently further improve this scheme by permitting relay node to transfer and distribute the virtual currency. Lu et al [21] propose a practical incentive protocol for DTNs which contains a fair incentive model. The source node will add incentive information to the to-be-sent message to encourage the selfish nodes to forward the message.…”

An investigation on the unwillingness of nodes to participate in mobile delay tolerant network routing

“…Recent years have seen considerable research works addressing the issue of selfish behavior in DTNs [32,63,37]. Traditionally, most works consider selfish behavior as the unwillingness of a single node to relay the messages of all other nodes in order to conserve its limited resources.…”

“…The existing incentive strategies are traditionally classified into three categories [4,8]: barter-based [4,3,59], credit-based [8,43,63,37,62] and reputation-based [1,56,11,57,37,28]. In the following subsections, we will introduce the representative strategies in each category and summarize their common problems.…”

“…In message purse model [63,37,8], the source node of a message pays credits to the intermediate nodes which participate in delivering the message to the destination. In the message trade model [43], messages are considered as valuable goods.…”

“…The strategies [37,8,63] belonging to the message purse model are suitable for different routing protocols. In [37], the proposed strategy is designed for the single-copy routing protocols (e.g., Direct Delivery and First Contact [18]) under which only one message copy exists in the routing process.…”