Phase I studied the problem of how to provide X-band communications between a small, manpack sized and small, mobile terminals and a large hub terminal. It became evident from the link budgets that such functionality is entirely feasible at data rates up to 2400 Bps. We propose here a demonstration program which is based on an existing Ku-band two-way communication system, called omni-tracs(Tm), which is currently operating over commercial ku-band satellite transponders. Our approach to the X-band demonstration system is to use the if and baseband portions of omni-tracs(Tm), which includes all of the critical signal processing functions, and to provide a modified front end and antenna to interface with the dscs iii satellite. We believe, from the results of the phase I SBIR effort, that we can provide two-way, 75, 300, and 2400 Bps operation between a small manpack terminal and a hub. The primary objective of this program is to demonstrate X-band communications between a manpack terminal and a large hub. However, a demonstration of ku-band operation represents a viable alternative, should it prove difficult to gain access to an appropriate large dscs terminal, and is offered as an alternative.
