Abstract Delay tolerant networks constitute the category of Mobile Ad hoc Networks and are characterized by the ab-sence end-to-end path connectivity with limited data sources and power, where intermittent data communication is always a challenging task. To overcome this network partitioning, node mobility is exploited to increase message delivery in routing of these networks. Human mobility patterns have a great affect in increasing performance of routing protocol. In this paper, we have addressed, gathered and studied various routing protocols in DTNs that have used user mobility patterns for routing. These protocols use the constructive or destructive social characteristics for improving the performance in message forwarding. We have studied the impact of users social relationships on the protocols' performance
