Skylink readies its 'thin-route' mobile satellite service

The development of Skylink, a 'thin-route' multiple satellite service capable of relaying 800 simultaneous voice or 2400-baud data channels using a downlink (806-902 MHz) spectrum is described. Each satellite in the system will have a PAM-D/DZ bus, and improved HELAPS (high efficiency linear amplification via parametric synthesis) amplifiers which will eliminate FDMA efficiency penalties while maintaining excellent intermodulation performance. Four methods will be used to obtain greater capacity from the 806 to 902 MHz spectrum: priority demand assigned multiple access (PDAMA); frequency reuse; orbital reuse; and more efficient modulation techniques. Skylink will provide data transmission service to areas with sparse population or terrain which normally precludes other types of transmission systems.