A dynamic two hops reputation assignment scheme for selfish node detection and avoidance in delay tolerant network

In recent years Delay/Disruption Tolerant Network (DTN) has been identified as the most promising and challenging areas of wireless communication where sparseness and delay are particularly high. It is emerging as a promising network in the areas of disaster response, inter-planetary, vehicular, military/tactical, underwater, satellite networks. DTN is characterized by the large communication latency and lack of end to end path from source to destination. Due to intermittent connectivity in DTN, data forwarding is possible using multiple hops in "store-carry-forward" manner. So, the entire data communication is solely dependent on the cooperation of the intermediate nodes or hops. However, these intermediate nodes sometimes may become selfish due to preserve its limited resources or due to some malicious intention [1][2]. In order to increase data delivery, the detection and avoidance of such selfish nodes are foremost required. Here we are using reputation based strategy where reputation can be used as a measure to detect the cooperation pattern of a node with other nodes in the network during data communication. In this paper, we propose a dynamic two hops reputation technique for detection and avoidance of selfish nodes where neighbor nodes will monitor the behavior of a particular node as forwarder and receiver. These one hop and two hops neighbor nodes will give their feedback after data communication takes place at certain interval. However, the universal reputation matrix will be published time to time based on the cooperation pattern of nodes by the Trusted Authority (TA). The performance of the proposed scheme was evaluated on ONE simulator [3].