ABSTRACT
This chapter addresses system and equipment aspects of uplinks and downlinks that are used for television contribution and distribution. It deals primarily with the C-band, Ku-band, and Ka-band frequency Fixed-satellite service satellites, as those are most commonly used by broadcasters. The commercial application of Ka-band satellites was first introduced by NASA's experimental Advanced Communications Technology Satellite, which demonstrated successful use of the 17.5 to 22.5 GHz downlink and 29.5 to 34.5 GHz bands for various services. Because the satellite serves as a transmit/receive station, it must be characterized by a G/T for the uplink side and by saturated equivalent isotropic radiated power for the downlink side. The frequency assignments are determined in joint negotiations by the countries of the world through the auspices of the Radio Communication Sector of the International Telecommunication Union. Communication satellites are provided with batteries to prevent circuit outages and to maintain pointing, attitude control, stationkeeping, telemetry, and command capabilities during eclipses.
