Buffer Management for Reliable Multicast over Delay Tolerant Networks

Flooding, earthquakes, and other disasters are recent phenomenons which unfortunately occur more and more often. After such occurrences, the infrastructure is likely damaged, but rescue teams need to communicate with each other to plan the rescue missions. Mobile Ad hoc Networks (MANETs) are an efficient and cost-effective opportunity to establish communication, if no working infrastructure is available. However, they come with several challenges, e.g. interruptions due to partitioned MANETs. Delay Tolerant Networks (DTNs) are a possible solution to overcome this problem. Furthermore, rescue missions require reliable communication between different rescue teams and among their team members. In order to efficiently reach all members of a team, multicast is promising. However, guaranteeing that all recipients receive a DTN multicast message is difficult and might consume too much buffer space in the DTN nodes. In this paper, we present our approach of a DTN-based multicast protocol that provides efficient buffer management without neglecting the required reliability. We explain our algorithm to efficiently free the node buffers. Our simulation results will show that our algorithm increases the delivery ratio for different group sizes.