Utilization of the 20-30 GHz spectrum part for high capacity national communications

The viability of satellite systems for national communications will be tested by an Italian preoperational 20/30 GHz satellite, projected for launch in 1984. With a capacity in excess of 10,000 telephone circuits, it features multibeam antennas, SS-TDMA with and without onboard regeneration, and voice processing techniques (DSI and/or ADPCM). Its objectives include performing high speed (approx. 1 Gbps) transmission experiments using transparent wideband transponders, and gathering propagation statistics for all Italian (long-distance network) compartments using measurements of absolute attenuation, differential attenuation, phase distortion, atmosphere depolarization, and raindrop canting angle. An operational satellite might have a basic bit rate of 120 Mbps (and possibly a 360 Mbps rate together with a phased array antenna) and would face problems of echo degradation as well as implementing a signalling system that is easily adaptable to satellite routing.