Fiber or microwave in underdeveloped or rural areas is generally the first technologies that come to mind when thinking about 5G cellular backhaul. What about satellite, though? It’s not as insane as it was several years ago, according to Chris Antlitz, the chief analyst at the Technology Business Research. Satellite communications have traditionally been provided via a series of geostationary orbiters orbiting far above the earth’s surface. At any given time, a single geostationary earth orbit (GEO) permits a single orbiter to serve a huge section of the world’s surface.
However, at 22,000 miles or more above the earth’s surface, global reach usually comes at a penalty of extraordinarily high latencies — 550 milliseconds or more. And it can be even worse in the instance of many outdated satellite networks. So, what happened to make satellite communications a feasible alternative for high-speed communications technology such as 5G? Quite a bit, if you ask Antlitz. The technology has become not only viable but also economically viable in the last two years.
One of the most significant changes is that the cost of sending satellites into orbit has decreased significantly because of the development of launch vehicles and reusable boosters by businesses such as SpaceX. Thanks to a transition to smaller, lighter, and increasingly technologically sophisticated medium-earth orbit (MEO) and low-earth orbit (LEO) constellations, vendors can now put more satellites in orbit than ever before.
Starlink has launched around 1,500 LEO satellites to date, with a total of 40,000 planned. SES currently has 20 MEO satellites in orbit, with 11 more sophisticated orbiters set to launch in the coming year. “The LEO satellites have a smaller form factor than GEO satellites, and they can be deployed into the stratosphere more easily,” Antlitz explained. “The economics of satellite has radically changed.”
The round trip that is between a base station and the user is significantly shorter because these satellites orbit closer to the surface. The constellation of Starlink is only 550 miles above the earth’s surface. Lower latencies are associated with a lower orbit. According to a recent Ookla assessment, Starlink can deliver latencies as little as 45 milliseconds, which is comparable to today’s 4G LTE.
Satellite-to-satellite communications are also possible thanks to the lower orbits of LEO and MEO satellites, which use a technology known as a phased array. Antlitz remarked, “It’s like a mesh network in space.” “At altitude, they’re basically using a microwave.”
Instead of just bouncing a signal from a satellite to the ground station, the signal may be replicated from satellite to satellite in just a few hops, allowing it to reach every location on the planet. He added that there are no barriers or weather to impede the signal, except terrestrial microwave networks.