Enhanced delegation forwarding in delay tolerant networks

Delay tolerant network (DTN) is a sparse wireless mobile network that does not guarantee a path between a source and a destination at any time. In DTN, one critical issue is to reliably deliver data with low latency. In an N -node network, naive forwarding approaches such as flooding and its derivatives make the routing cost very high (O(N)). Recently, an approach called delegation forwarding (DF) caught significant attention in the research community because it reduces the cost to O( √ N) while maintaining good performance. In this paper, we enhance the DF algorithm by proposing a probability delegation forwarding (PDF) that further reduces the cost to O(N 2+2p), p ∈ (0, 1) and a threshold-based probability delegation forwarding (TPDF) that closes the latency gap between DF and PDF. Simulation results show that both PDF and TPDF can achieve similar delivery ratio as DF at a lower cost if p is not too small.