NWBBMP: a novel weight-based buffer management policy for DTN routing protocols

A delay-tolerant network (DTN) is a network with dynamic topology changes, network partitions and node mobility. Multi-copy routing protocols are usually adopted to overcome these characteristics. Although multi-copy routing protocols can improve the message delivery ratio and reduce the message propagation delay, they also easily exhaust the limited storage space of nodes, resulting in buffer overflows. The major task of buffer management is to determine which message will be discarded when buffer overflows happen. Determining the order of discarding messages will directly affect the performance of the network. In this paper, we propose a novel weight-based buffer management policy (NWBBMP) that divides messages in the node into a priority message queue, a high-weight message queue and a low-weight message queue. When a node receives a new message that causes a buffer overflow, the algorithm determines which queue’s messages will be discarded according to whether the current node is the destination node of the new message. Simulation results show that our algorithm outperforms traditional buffer management algorithms in terms of delivery ratio, average delay and network overhead.