Multicasting in Delay Tolerant Networks: Delegation Forwarding

Delay tolerant networks (DTNs) are a kind of wireless mobile network which may lack continuous network connectivity. Multicast supports the distribution of data to a group of users, a service needed for many potential DTNs applications. While multicasting in the Internet and mobile ad hoc networks has been studied extensively, due to the unique characteristic of frequent partitioning in DTNs, multicasting in DTNs is a considerably different and challenging problem. It not only requires new destinations of multicast semantics, but also brings new issues to the design of routing algorithms. In this paper, we propose new forwarding models for DTNs multicast and develop several multicast forwarding algorithms. We use delegation forwarding (DF) in DTNs multicast and compare it with single and multiple copy multicast models, which are also designed by us. The effectiveness of our approach is verified through extensive simulation.