Contact frequency and contact duration based relay selection approach inside the local community in Social Delay Tolerant Network

Abstract

Social Delay Tolerant Network (DTN) allows mobile devices to exchange the data opportunistically without end-to-end path when they come in contact. As the connectivity is opportunistic so, the routing task becomes very challenging. By investigating the real social network traces, it exhibits that a node tends to meet a certain group of nodes more frequently and regularly compared to other nodes outside their group which forms the local community. There are many social characteristics (e.g. centrality, similarity) of human beings which are exploited to select the appropriate relay node. Many community based routing protocols proposed in the literature which select the relay node as one of the community members or the most central node inside the community. In this paper, we propose two different approaches of the relay selection inside the local community: contact frequency based approach and contact duration based approach. When message carrier and encountered node belongs to the same community of the message’s destination, the relay selection is done based on contact frequency and contact duration of the node with the message’s destination. It is usually inside the social community that people in the same community meet very often and spend more time with only a few members of their community than all other members. To evaluate the performance of our approaches, we choose the real traces from the campus and the conference environment. The simulation result on the real traces shows that the proposed approaches of selecting a relay node outperform better in terms of delivery ratio for the campus environment where as they perform quite similar as an existing scheme in the conference environment.