Analysis of ground segment broadcast architectures for the Wideband Gapfiller Satellite (WGS)

The purpose of this paper is to summarize the findings of an assessment tasked by the joint staff regarding the broadcast ground segment architecture for the Wideband Gapfiller Satellite (WGS). WGS has the capability to permit Global Broadcast Service (GBS) injection at either Ka-band (30 GHz) or X-band (8-GHz), and be cross-banded and received by current GBS receive-only suites at 20-GHz. Original plans were to buy three new GBS Ka-band injection terminals to support GBS on WGS; however, to save costs, one alternative is to use existing DSCS X-band terminals to perform the GBS injection on WGS with crossbanding to the current Ka-band GBS receive suites. Then, as UHF Follow-On (UFO) GBS satellites reach their end of life, the existing Ka-band GBS injection terminals will replace the X-band injection, freeing the latter for other missions. This paper examines various options and provides recommendations for GBS injection on WGS in consideration of the available Xand Ka-band bandwidth and the corresponding antenna coverage issues. This paper also discusses an option for GBS reception at X-band for sites with existing X-band two-way services. Based on this capability, the paper shows options for a Ka-only GBS, cross-banded Ka-to-X band GBS, X-to-Ka-band GBS, and X-to-X-band GBS. Planned use of these options will provide coverage flexibility and ease the current planning burden and will minimize the amount of beam movement to achieve desired worldwide coverage goals.