Monday, November 13, 2017

Telesat -- a fourth satellite Internet competitor

Telesat will begin with only 117 satellites while SpaceX and the others plan to launch thousands -- how can they hope to compete? The answer lies in their patent-pending deployment plan.

Polar (green) and inclined (red) orbits
I’ve been following SpaceX, OneWeb and Boeing’s satellite Internet projects, but have not mentioned Telesat's project. Telesat is a Canadian company that has provided satellite communication service since 1972. (They claim their "predecessors" worked on Telstar, which relayed the first intercontinental transmission, in 1962). Earlier this month, the FCC approved Telesat's petition to provide Internet service in the US using a proposed constellation of 117 low-Earth orbit (LEO) satellites.

Note that Telesat will begin with only 117 satellites while SpaceX and the others plan to launch thousands -- how can they hope to compete? The answer lies in their patent-pending approach to deployment. They plan a polar-orbit constellation of six equally-spaced (30 degrees apart) planes inclined at 99.5 degrees at an altitude of approximately 1,000 kilometers and an inclined-orbit constellation of five equally-spaced (36 degrees apart) planes inclined at 37.4 degrees at an approximate altitude of 1,248 kilometers.

This hybrid polar-inclined constellation will result in global coverage with a minimum elevation angle of approximately 20 degrees using their ground stations in Svalbard Norway and Inuvic Canada. Their analysis shows that 168 polar-orbit satellites would be required to match the global coverage of their 117-satellite hybrid constellation and according to Erwin Hudson, Vice President of Telesat LEO, their investment per Gbps of sellable capacity will be as low, or lower than, any existing or announced satellite system. They also say their hybrid architecture will simplify spectrum-sharing.

The following figure from their patent application illustrates hybrid routing. The first hop in a route to the Internet for a user in a densely populated area like Mexico City (410) would be to a visible inclined-orbit satellite (420). The next hop would be to a satellite in the polar-orbit constellation (430), then to a ground station on the Internet (440).

An inter-constellation route (source)

The up and downlinks will use radio frequencies and the inter-satellite links will use optical transmission. Since the ground stations are in sparsely populated areas and the distances between satellites are low near the poles, capacity will be balanced. This scheme may result in Telesat customers experiencing slightly higher latencies than those of their competitors, but the difference will be negligible for nearly all applications.

They will launch two satellites this year -- one on a Russian Soyuz rocket and the other on an Indian Polar Satellite Launch Vehicle. These will be used in tests and Telesat says a number of their existing geostationary satellite customers are enthusiastic about participating in the tests. They will launch their phase 2 satellites beginning in 2020 and commence commercial service in 2021. They consider 25 satellites per launch vehicle a practical number so they will have global availability before their competitors. Their initial capacity will be relatively low, but they will add satellites as demand grows.

Like OneWeb, Telesat will work with strategic partners for launches and design and production of satellites and antennae. They have not yet selected those partners, but are evaluating candidates and are confident they will be ready in time for their launch dates. Their existing ground stations give them a head start. (OneWeb just contracted with Hughes for ground stations).

Their satellites will work with mechanical and electronically steered antennae and each satellite will have a wide-area coverage mode for broadcast and distributing software updates. Their patent application mentions community broadband and hotspots, large enterprises, ships and planes, software updates and Internet of things, but not homes as initial markets.

Telesat's Canadian patent application goes into detail on all of the above, and I'd be curious to know what exactly would be protected by it. They also consider their global spectrum priority rights from the International Telecommunication Union as an asset, but they will have to agree to spectrum sharing conventions and debris mitigation agreements.

Let me conclude with a suggestion for Telesat and the Cuban government.

OneWeb has committed to providing coverage to the entire state of Alaska by the end of 2020 and Telesat says they will have global coverage by 2021. I follow the state of the Internet in Cuba and think Cuba would be a good starting place for Telesat service. Cuba has the best-educated, Internet-starved population in Latin America and the Caribbean, they have very little domestic Internet infrastructure and much of the infrastructure they do have is obsolete. Cuba is close to being an Internet "green field" and, since it is an island nation, their polar satellite "footprint" would not be densely populated.

Cuba could work with Telesat to leapfrog over several infrastructure generations. If Telesat can deliver on their claims, the barriers would be political and bureaucratic, not technical. Cuba is about to change leadership, and there is some indication that Miguel Díaz-Canel, who many expect to replace Raúl Castro, will favor Internet development.

SpaceX could also provide early Cuban connectivity, but dealing with a US company would be politically problematical and Cuba and Canada have a well established political and economic relationship. Even if Cuba were willing to work with SpaceX, the current US administration would not allow them to do so. Connecting Cuba would be good for Cubans and good publicity of Telesat.

For more on Telesat and their plans for LEO satellite Internet service see their patent application and you can see animations of their proposed hybrid-constellation connectivity here and here.