Location-aware utility-based routing for store-carry-forward message delivery

One of the most important technical problems in store-carry-forward routing is to reduce the number of message copies in networks without increasing the message delivery delay. In order to solve this problem, we focus on utility-based routing schemes, where for a message, utility of a node indicates its proximity to the destination node of the message. Utility-based routing schemes are promising when relay nodes, i.e., nodes with the message (copy), have sufficient opportunities to encounter other nodes. On the other hand, when relay nodes are in extremely sparse areas of nodes and they have few opportunities to encounter other nodes, the routing schemes do not work effectively. This observation naturally leads us to propose a location-aware utility-based routing scheme. The proposed scheme combines a utility-based routing scheme with location-aware probabilistic forwarding, where the forwarding probability is determined based on both node utility and node density at the contact location. With several simulation scenarios, we evaluate the performance of the proposed scheme in terms of the mean number of copies in the network and the mean message delivery delay.