A new kind of space race is on. If all goes according to plans, a few thousand satellites will be orbiting the earth to provide internet connectivity from space. These are a new generation of high-capacity satellites that will orbit at relatively low altitudes to provide unprecedented performance from space-based networks. These low-earth orbit (LEO) satellites will be circling between 500 and 2,000 km above the earth surface and reduce signal delay by over 5 times from geostationary satellites (sub 100 msec vs. 500 msec). LEO satellites promise to have far-reaching consequences on the established ecosystems.
Background
In the early to mid 2000’s a new generation of satellites, known as high-throughput satellites (HTS) was launched into geostationary orbit (35,786 km). They provided on the order of 1-2 Gbps of throughput. Today, the fifth generation of these satellites are planned for launch by companies such as Viasat and Hughes with peak capacity of up to 1 Tbps. The main drawback of these satellites is signal delay (~500 msec). Overall, HTS have been successful at capturing subscribers for Internet services with competitive pricing. There are no less than 1.5 million such residential subscribers in North America alone.
The increase in satellite capacity came about by a number of technology and regulatory factors. The then newly-introduced Ka band provided higher capacity based on wider frequency channels than low frequency bands. Phased-array antennas provided narrow beams for tight frequency reuse, similar to terrestrial cellular systems. Advances in modem design, modulation and coding improved capacity and robustness.
Emergence of LEO
LEO satellites have been around for decades and used for different type of services, including data and machine-to-machine connectivity. Iridium launched in the 1990’s is an example of a well known constellation, perhaps because of its commercial failure. Other constellations include Globalstar, and M2M/IoT services such as Orbcomm and Gonets.
The economics for LEO satellites are very different today to what they were in the 1990’s. The cost for launch and the actual satellites is much lower than it was. On May 24th, SpaceX launched 60 satellites using one Falcon 9 rocket. Of course, it helps that these satellites are smaller in size and lower in weight than GEO satellites. The economics have led some LEO players to plan bold constellations, such as:
- SpaceX Starlink: between 900 and up to 12,000 satellites.
- OneWeb: up to 900 satellites.
- Telesat: over 290 satellites.
- Leosat: up to 108 satellites.
- Kuiper (Amazon): about 3,237 satellites.
- Hongyan (China): over 250 satellites.
The Capacity Consequences
Based on our estimates, the offered capacity by space satellites will increase multiple folds over the current level. It becomes imperative to expand the markets and applications of satellite services to absorb the ‘glut’ of capacity. LEO service are global which opens new market opportunities in contrast with the regional-focused GEO services. It also helps that LEO constellations will provide Layer 2 and Layer 3 services natively, and will be ready to integrate into terrestrial networks. Nevertheless, there is a level of risk in penetrating new markets and developing new applications. But the consequences could be far-reaching to both other satellite service providers and terrestrial network players.
Potential Consequences to LEO Services
Traditional customers of satellite services – e.g. governments; maritime and shipping industries – will have the option for much improved performance. Aviation is one of the fastest growing applications for satellite communications. Today, airplanes are among the few places where one can still be ‘beyond coverage’. As satellite connectivity becomes commoditized, that will soon be part of the past. This is perhaps the one area that the new LEO constellations will impact the average consumer directly.
A common message is connecting the unconnected. The economics of backhaul present a high barrier to rural and remote access services. LEO communications will lower these economic barriers but will not eliminate them. LEO will impact current terrestrial system vendors. The full consequences on incumbent ecosystem players remains to be assessed.
Residential broadband is an area to watch because it is contested with fixed wireless access (FWA) technologies. FWA have had the upper hand as subscribers opt for the reliability, performance and cost of FWA. Environmental factors such as rain, snow and sand affect satellite links causing service outages. Should LEO systems prove to be reliable, the competitive gap with FWA will shrink. Consumers will have another choice as opposed to a FWA monopoly. The impact will remain limited to rural areas and not affect urban areas.
A Final Thought
Satellite is the “service of last resort”: we use satellites when all else fails or is not available. LEO promises is to change this so that satellite services are “another tool in the kit.” For this to happen, it will be critical for LEO to provide reliable performance within predictable bounds. This is fundamental in anything that’s wireless communications: unpredictability leads to failure and must be eliminated to achieve commercial success.
Historically, the launch of new wireless networks (e.g., 2G to 5G, WiMAX, UMA, etc.), the terminals/devices were the achilles heel in terms of availability, broad choice, price, and power. Any info/thoughts on the rollout of LEO terminals/devices?
Will be available to align with commercial service. They are about a year away, depending on constellation.