Abstract
In DTN, a small amount of selfish nodes occupy the storage of specific key nodes with stronger transfer capacity in hot spot region which greatly consumes the limited network storage resource. This causes congestion and reduces the successful delivery ratio of messages from other nodes. This paper adopts pigeonhole principle and power in combinatorics to define node's responsibility range of message transfer for other nodes. It is helpful for the nodes to selectively accept messages which are required to be transferred and deliver them. The algorithm should restrict the selfish behavior of selfish nodes, reduce network congestion and guarantee the reasonable share of storage resource by all nodes according to the communication frequent degree. The experiment proves that congestion control routing algorithm against node selfish behavior based on pigeonhole principle (CRASP) proposed in this paper excellently achieves the above objectives.