The announced Eutelsat-OneWeb merger claims to be the world’s first combination of geostationary orbit (GEO) and low Earth orbit (LEO) constellations, creating an opportunity to utilize the advantages of both to address the growing market for satellite connectivity.
The merger brings two operators’ satellite constellations together, promising to combine strengths of 36 Eutelsat GEO satellites with OneWeb’s 648-strong LEO constellation. The announcement mentions intentions of creating a single GEO/LEO services platform over time, which will provide services to customers using hybrid terminals. The intention of the merger makes sense conceptually: GEO platforms will provide superior per-unit capacity and compelling economics, while LEO satellites will provide ubiquitous coverage and low latency.
Combining GEO/LEO will be a challenge
However, even with announced hybrid terminals capable of accessing both networks (which have yet to be developed), combining GEO/LEO operationally will be a significant challenge. GEO and LEO satellite constellations are very different systems. GEO satellites operate in much higher orbit (35,786 km) and appear fixed over a point on Earth’s surface; their numbers are usually small (36 in Eutelsat’s case), and each satellite features very high-capacity and very wide-area coverage.
LEO satellites, on the contrary, operate in much lower orbit (2,000 km or less) and are moving relative to Earth’s surface; they feature relatively limited capacity (compared to GEO satellites), but are much more numerous, with constellations consisting of hundreds and thousands of units.
The broadband services provided by GEO and LEO differ too, as a result of the two constellation types’ technical differences. GEO satellite broadband offers high capacity, but its latency is very high (measured in hundreds of milliseconds). The need for handovers in GEO networks is relatively low, and it affects primarily fast-moving terminals, like airliners. LEO satellites, because of their lower, per-satellite capacity, can get congested more easily if overflying an area with a lot of active users; they provide much better latency, but also create a lot more handovers as they move relative to all users, including stationary ones.
Eutelsat/OneWeb will face fierce competition
The ideal solution for combining the strengths of these two networks would be to route user traffic to GEO or LEO satellite constellations based on the use case; GEO can serve large downloads and one-way video streams better, while LEO supports interactive two-way services. This type of operation requires a cutting-edge, complex, network control mechanism, which needs to include the user terminal as well. The bad news for the new operator is that it will likely be a pioneer in developing such a solution. The good news is that similar control mechanisms will become more commonplace soon, as 6G networks are projected to combine static (terrestrial) and LEO assets.
But even once the technology hurdles are overcome, the Eutelsat/OneWeb combination will still face formidable competition in the LEO space – primarily from the current LEO leader Starlink, which already has well over 2,000 satellites in orbit, dwarfing OneWeb’s constellation. The only way the new GEO/LEO player can carve out a place in the sun in a Starlink-dominated market is to perfectly execute its technology roadmap and deliver a cost and performance-competitive service to the marketplace, which will be a significant challenge.