A framework for multi-region delay tolerant networking

Almost all the existing work on routing in delay tolerant networks has focussed on the problem of delivery of messages inside a single region, characterized by the same network infrastructure and namespace. However, many deployment scenarios, especially in developing regions, will probably involve routing among different regions composed of several heterogeneous types of network domains such as WiMAX or satellite networks and ad hoc networks composed of short-range radio enabled devices, like mobile phones with Bluetooth interface. In this paper, we introduce a proposal for inter-region routing based on both probabilistic and deterministic forwarding mechanisms, embedded in an architectural framework able to support it. We also compare our solution to existing approaches in delay tolerant networking, discussing the main requirements and possible solutions, and outlining the open research problems.