Bubble rap incentive scheme for prevention of node selfishness in delay-tolerant networks

Abstract

Delay-tolerant network (DTN), as its name suggests, is a network architecture that can tolerate delays in message delivery. In such an environment where there is a high rate of error and very large delay, routing becomes a challenging task due to the extreme conditions. DTNs incorporate store carry-and-forward routing technique to transfer data from source to destination using a new protocol called Bundle Protocol. While implementing this technique, it is assumed that each node cooperates in data forwarding and forwards the message irrespective of its sender and destination. But sometimes nodes may deny data forwarding and accepting messages of other nodes in order to save its own resources such as bandwidth and buffer. Such behaviour is termed as selfish behaviour whereby node may drop packets of other nodes or prevent them from forwarding further in order to save its own resources. Detecting selfish behaviour of nodes in DTN environments is a critical task. In order to overcome the selfish behaviour, nodes may be motivated by providing incentives in form of credits or virtual money. This paper presents a technique to detect selfishness of a node on the basis of its message forwarding and dropping behaviour, and a novel credit-based scheme to motivate nodes to cooperate in message forwarding. The proposed scheme is applied over Bubble rap routing algorithm which is a popular social-based routing algorithm.