Future High Throughput Satellite systems

Abstract

KA-SAT represents the first of the current generation of High Throughput Satellites (HTS). With a total system capacity of over 70 Gbit/s and the capability of supporting up to a million users, it delivers services akin to those provided by the terrestrial ADSL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> . Whilst supporting services that include corporate networks and Satellite News Gathering (SNG), KA-SAT has primarily been designed for the consumer broadband market. In general, the consumer tends to be rather technology agnostic and the bench-mark is expected to remain the terrestrial services. This implies that as fibre-to-the-home (FTTH) becomes more prolific, it will become the yardstick for HTS systems. This is a daunting prospect for the satellite communication system architect since FTTH represents a bit rate approximately an order of magnitude more than that of ADSL <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> for about the same cost. This paper investigates three key areas: 1) The tradeoffs between power and spectrum in an HTS system and how spectrum is the dominant contributor; 2) Regulatory aspects in developing such systems; 3) How a top level forecast can be generated for HTS systems that can provide a significant increase in system capacity considering available spectrum, the enabling technologies and the scheduling.