Origins and Characteristics
The “traditional” model of networks that we are familiar with fails to work when certain fundamental assumptions, such as availability of end-to-end communications paths and short round-trip times, do not hold true. Delay-tolerant networks (DTNs) were proposed to enable communication in such scenarios by leveraging the store-carry-and-forward mechanism of message transfer. In this chapter, we look at the origins of DTNs, their characteristics, and different variations such as opportunistic mobile networks (OMNs). This chapter also presents a short review of some of the popular research areas in DTNs/OMNs. The chapter concludes with a brief overview of network simulations. Many of these topics would be discussed at a greater depth in the remainder of the book.