We’re not referring to hybrid satellite-terrestrial (ATC/CGC) networks, but to the details of Inmarsat’s long term satellite development plans for its Inmarsat-5 constellation revealed at today’s investor meeting in London. Though its fifth generation satellites are not due to be launched for nearly ten years, Inmarsat is already actively developing plans for satellites which include both L-band and higher frequencies, not just a “cheap and cheerful” low cost evolution of its current satellites.
Inmarsat doesn’t plan to develop what it characterized as “high risk” L-band satellites with ground-based beamforming (which is being employed by ICO, TerreStar and SkyTerra, with no apparent problems that we can discern), but instead is looking at including other frequency bands in the I5 constellation. In addition to indicating that S-band is not needed for its core business (but would instead be used mainly for terrestrial applications), Inmarsat suggested that standard FSS frequencies (i.e. Ku-band) were not particularly interesting. Thus we conclude Inmarsat may have a preference for including military Ka and/or X-band capacity on the I5 satellites. With the US government deploying its own Wideband Global System (WGS), there will be many thousands of DoD terminals in the field capable of using these frequency bands by the time the I5 constellation is launched.
Potentially the I5 satellites could provide surge capacity for the DoD (and other defense agencies) to supplement the government-owned WGS satellites, and provide incremental revenue opportunities for Inmarsat. Alternatively, Inmarsat could carry a hosted WGS-derived payload, in the same way as Intelsat recently agreed to carry a hosted UHF payload for the Australian Defense Force. According to figures provided at the conference, Inmarsat already receives 37% of its revenues from government services, and either approach would cement or even increase the proportion of revenues from government in the future.