3. BENCHMARKING AND MODELING OF ROUTING PROTOCOLS FOR DELAY TOLERANT NETWORKS

Delay Tolerant Networks (DTNs) are characterized by their intermittent connectivity, frequent partitioning, long message delays, and lack of end-to-end communication paths. In the year 2002, the Internet Research Task Force (IRTF) documented a DTN architecture specification for interplanetary communication [3.1],[3.2]. Later on, in addition to the space communication, the focus of DTN research also shifted towards establishing communications in the challenging terrestrial network environments, such as sparsely distributed mobile ad-hoc networks and wireless sensor networks. Fig. 3.1 presents a few application areas of DTNs.