Sociality-Based Buffer Management for Multicast in DTNs

In Delay Tolerant Networks (DTNs), multicast is widely adopted for emergency notification in crisis environments and data scattering under military rescue situations, due to its robustness and high resource utilization. Although the topology of DTNs is highly dynamic, they also demonstrate relatively stable social characteristics, e.g., the social centrality. In this paper we propose a sociality-based buffer management for multicast routing (SBMR), where nodes with high social centrality are selected in priority as relay nodes. As choosing nodes with high centrality may result in large transmission workload on these nodes, and consequently they have to drop messages frequently when the buffer space is limited. We design a corresponding buffer management strategy that drops the buffered messages with most replicas in the network. This will save the buffer space for the messages with fewer replicas, which has not been well-distributed in the network. Through extensive simulation, we verify that SBMR can increase the data delivery ratio significantly without compromising the transmission cost and delay.