Datagram-transfer protocol for UHF SATCOM

The joint UHF MILSATCOM Technical Working Group (TWG) is in the process of updating the demand assigned multiple access (DAMA) waveform standards that specify operation over 5-kHz and 25-kHz UHF military satellite channels. While the existing waveform standards have greatly increased the number of communication services supported by UHF SATCOM, the transition from using UHF resources on a dedicated-channel basis to DAMA operation is proceeding very slowly. One factor that has slowed the switch to DAMA operation is that there are many UHF communication requirements that cannot be efficiently supported by the existing waveform standards. The existing standards define protocols primarily for the transmission and reception of serial (streaming) data. However, there is a growing demand for a datagram-transfer protocol capable of supporting a wide variety of protocols at higher layers, including Internet protocols. This paper examines distributed and centralized control of datagram transfers and discusses characteristics of typical UHF terminal architectures, such as the red-black interface, that place restrictions on the datagram-transfer protocol. Considering these factors, this paper proposes a data link protocol that provides control over the use of a DAMA time slot, and a network protocol that supports a local area network (LAN) connection to baseband equipments. Incorporation of these protocols into the updated standards would allow new and updated terminals to provide efficient support for a wide variety of higher-layer data connectivity protocols. Finally, this paper provides a discussion of the improved link performance made possible by use of the proposed protocols.