Routing Based on Information about the Routes of Fixed-Route Traveling Nodes and on Destination Areas Aimed at Reducing the Load on the DTN

In recent years, the interest in delay/disruption tolerant networking (DTN) is growing as a means of communication in times of disaster. To ensure that a DTN works well in an emergency, it is desirable to promote general use of the DTN, so that it will also be used in normal times. Since the DTN uses mobile terminals and vehicles, which are not dedicated network devices, as relay nodes, the routing method should be such that it does not impose a large processing load on relay nodes. This paper considers use of a DTN for a day-to-day service of delivering content to a specific area and proposes a new routing method that is based on information about the routes of fixed-route traveling nodes, such as public transportation vehicles. The destination of a bundle is specified not by a terminal identifier, but by an area, which is identified by its location information. This paper presents an outbound-type bundle protocol, which is used by relay nodes when they have received a forwarding-bundle request from a sending terminal and try to determine whether the bundle can reach its destination area. Using simulation, the superiority of the proposed routing was confirmed by comparing it to existing routing methods in terms of the bundle arrival rate and factors that affect the network load, such as the number of bundle copies, the number of hops and the maximum required buffer size.