Are Low Earth Orbit Constellations the Next Step in Deploying Mobile-TV?

Abstract

In Europe, operators have started the deployment and commercialization of the third generation (3G) of mobile systems. For the time being, only terrestrial infrastructures are deployed despite the possible benefits of a satellite component. Up to now, mobile satellites are serving point-to-point communications from either Low Earth Orbit constellations (Globalstar, Iridium) or geostationary satellites (Inmarsat, Thuraya...). In point-to-point applications, satellites have limitations compared to terrestrial networks: low capacity, limited data rates, latency, poor indoor penetration and specific standards. Nevertheless, mobile satellites have started to play a significant role in the provision of radio/TV broadcast services (DARS and S-DMB). There is a growing interest in the use of satellites to provide a broadcast overlay to 3G terrestrial networks. Based on GEO satellites, these systems imply the deployment of a terrestrial retransmission network, known as Ancillary Terrestrial Component or Complementary Ground Component, to mitigate the intrinsic limitations of communications from the geosynchronous orbit. In the short run, such a system could be deployed over Europe to provide a first taste of Mobile-TV services. Later on, a global Mobile-TV system could greatly benefit from using LEO satellites. This paper illustrates the advantages of a LEO constellation for broadcasting Mobile-TV. It describes a constellation and its satellites of which design backs up on the past experience and technologies, but involves also new innovative technologies.