A temporal validity based buffer management scheme in content-centric DTNs

Due to the intermittent connectivity of content-centric opportunistic networks, data dissemination is often performed by replication which easily leads to network congestion. Many existing message forwarding or dropping strategies provide congestion avoidance based on only the node-related metrics or the message-related metrics, i.e. the meeting history between nodes, the number of subscribers, message hop count etc. However the temporal validity of user interest is ignored in most cases. In fact, the interests of users may have different durations. A message is unnecessary to be forwarded when the nodes have lost interests in it. Therefore, we present the first attempt to apply the validity duration of user interest in message dropping decision and present a novel temporal validity based buffer management scheme. In this scheme, a multi-attribute utility is designed to decide the dropping priority of messages from the standpoints of node, message and interest. Simulation results prove the superiority of our scheme with respect to delivery ratio, dissemination speed and overhead.