DBS television systems under development in the United States of America

DBS system technology tradeoffs which were being considered as of October 1984 are reviewed. The economic goal is to provide acceptable image and programming quality at costs lower than those of CATV systems. Although receiver dish antenna costs are incurred by the DBS user, the satellite link avoids the capital intensive cable infrastructure. The DBS antennas may cause legal difficulties as DBS subscribers receive CATV regional unscrambled feeder signals. DBS service at 11 GHz has already begun in the NE U.S. with the Anik C2 satellite, which provides a 10 dB clear sky carrier/noise (C/N) ratio signal. Transponders on a Comsat DBS system (in advanced development) will employ vertically polarized signals to attain C/N ratios over 17 dB in concert with 75 cm home terminal antennas. The FCC has ruled that all DBS equipment shall have sufficient commonality at the receiving end so that a customer will need only to replace a baseband processor unit to change sources.