At Satellite 2018 last month, everyone in the satellite industry (emphasis mine) talked up how 5G deployments and satellite can work together. It was funny and sad at the same time, since there hasn’t been a lot of discussion in the wireless industry — i.e. the carriers actually spending money to get 5G up and running — on how to integrate satellite broadband into terrestrial-based networks.
There are three big use cases for 5G, according to the cellular marketing machine. Case one is a massive Internet of Things (IoT) framework, communicating with millions to billions of devices. Satellite has a role to play in IoT, since it already connects “things” that move — planes, trains, automobiles, ships, and cruise lines, but you don’t really need 5G definitions and overhead to do IoT today. And there’s already a lot of existing satellite IoT installed in the two decades since Iridium and ORBCOMM rolled into the IoT/M2M world.
Network virtualization is where 5G may have an advantage over existing infrastructure. A carrier could define a “virtual” IoT network within 5G, with the satellite IoT nuts-and-bolts (radios and satellites) hidden to the customer. All most users want to see is data from “things” in one dashboard. If 5G can seamlessly integrate satellite into a larger IoT framework, everyone should win.
High speed, low latency broadband delivery is the second use case. Today’s satellite broadband services, with few exceptions, run into a latency brick wall. Long-established geosynchronous earth orbit (GEO) services run signals between the ground and satellites 22,300 miles above the global. Relaying a signal through a GEO satellite between point A and B adds over half a second (540 milliseconds) of latency round trip due to the distance involved.
Target goal for 5G network latency floated by some hardware manufacturers is as low as 1 to 2 milliseconds, but will likely run single digit or low double digits in real world use. Typical performance on a 4G LTE, last generation, old and busted wireless network is “only” 50 milliseconds — or less than one-tenth the time a single hop through a GEO satellite takes.
The third use case is for real-time control of things, be it drones or factories or robots performing remote surgery. See use case two goals for low latency to enable real-time control in a factory setting. How 5G might perform better than a stock fiber network has yet to be addressed in a holistic fashion, with a bigger issue in my mind being how “traditional wireline” infrastructure needs cleanup and optimization to support 5G speeds.
If latency matters, geosynchronous satellites have little to no role to play in a 5G broadband network. Satellite firms have long brushed off latency as being a factor for consumers or businesses, but that’s like phone companies back in the late 1990s telling people “You’ll only need a megabit with DSL, nobody will ever need 10 Mbps. And 100 Mbps is just crazy talk, I tell you.”
Once users get a taste for better service — faster broadband last cycle, 5G low latency this cycle — they’ll select the best option with the best features and characteristics. And if they actually NEED those services, such as low latency, they will pay extra to get them.
GEO services aren’t the only game in town, however. Medium earth orbit (MEO) and low earth orbit (LEO) services deliver dramatically lower latency than GEO. O3b mPOWER, a division of SES, positions its fleet of satellites at an altitude of around 5,000 miles above the Earth’s surface, giving the company a stated round trip latency of less than 150ms through its network. MEO-style networks with satellites located between 1,200 miles and 5,000 miles above the earth get us into the ballpark where satellite becomes useful for voice and data services without paying a “latency penalty.”
LEO communications constellations, the new hotness in the satellite industry, should drop latency to between 25 to 50ms, depending on which provider you talk to and how close you fly to Earth. While 25 to 50ms isn’t exactly a 5G single digit latency promise, it’s probably good enough for most real-time communications applications, including voice and gaming.
SpaceX, OneWeb, and Telesat are all in the process of building LEO networks. Telesat plans to launch a paltry 120 satellites for its phase one network. OneWeb’s phase one network will be 648 satellites while SpaceX is planning a whopping 4,425 satellites for its initial constellation. All three networks are expected to reach full operational capacity in the early 2020s.
When the marketing hype clears, cellular networks could benefit by using MEO and LEO broadband services to extend coverage in underserved and unserved areas. SoftBank’s investments and work with OneWeb and Sprint suggest the two firms could use OneWeb’s LEO network to enhance Sprint’s rural coverage across the U.S. (And may extend to T-Mobile if the merger goes through).
Talk of 5G and satellite being best buddies, however, is more hype and less reality at this point in time. The wireless (cellular) industry and carriers are the ones who are defining network and service requirements, terms of engagement, and write checks at the end of the day.
Does satellite have a role in expanding cellular networks? Yes, especially low latency services such as O3b and the crop of forthcoming LEO networks. Is satellite good enough to support 5G deployments? It’s hard to say, since cellular companies are setting the latency bar high (well, low) and are just starting to grapple with how 5G services are going to be deployed as well as solidifying definitions on what 5G will deliver.