Delay-tolerant networks (DTNs) for satellite communications

This chapter discusses the advantages of delay/disruption-tolerant networking (DTN) when applied to satellite communications, considering geosynchronous (GEO) and low Earth orbit (LEO) constellations. The chapter analyses the challenges of GEO communications and shows how the DTN architecture can be interpreted as an elegant architectural extension of TCP-splitting PEPs, with the same excellent goodput performance but with better robustness and superior compatibility with security protocols. It examines LEO constellations and highlights the advantages offered by some bundle protocol features, such as scheduled links, and by contact graph routing (CGR), a DTN routing algorithm designed by NASA to cope with intermittent scheduled connectivity typical of both LEO satellite and deep-space communications. Results prove that the DTN architecture, although still experimental, is mature enough for real deployment.