An artist’s rendition of the future OneWeb communication satellite. They will provide wireless connectivity to commercial and military aircraft.
Low Latency, Global Coverage
Michael Weinhoffer/Staff Reporter
Recently, there has been a good amount of news on the proposed satellite constellations of OneWeb and SpaceX. These new systems are designed with the intention of low latency and global coverage. But what does this mean? And when can we see them in action?
The thought of providing digital services to the entire world is not new. Instead of crowding the environment with thousands of cell towers, it was instead proposed to use multiple satellites in space to provide services to both remote and non-remote locations. The first applications of this concept were in military communications. The Global Positioning System (GPS) of the U.S. Air Force quickly became the premier model for satellite communications. Currently, China, Russia and the European Union also have operational global navigation satellite systems around 20,000 km from Earth in a medium Earth orbit. These constellations allow GPS systems, ATMs, gas stations and more to operate precisely, and are vital to the global economy.
There is an even more apparent use of satellite constellations. The multiple operational commercial satellite constellations provide key communication services that everyone takes for granted. Companies such as Iridium, EchoStar, and SES provide phone and video services for the entire world. Because of some malfunctioning satellites, the entire world is not covered. For example, malfunctioning Iridium satellites have left portions of the equatorial region the world uncovered, and there is generally low coverage liability near the poles. Another key element of communication satellites is the transmission latency. Latency refers to the delay between a satellite receiving a signal and the transmitting signal going to the ground station. Have you ever wondered why there seems to be a noticeable talking delay between news presenters in the U.S. and correspondents in foreign nations? That is a perfect example of a high latency transmission. Satellites farther away from Earth will have a higher latency period than satellites close to Earth. A long transmission delay period damages the reliability of the communications system. Unlike most communication satellites, Iridium satellites are in low earth orbit, which reduces the latency period but requires more satellites to provide reliable coverage. A key challenge for the modern communication satellite constellation is to have low latency, but global coverage. Low latency improves signal reliability, but it comes at a much higher cost to ensure global coverage.
This is where the OneWeb satellite constellation comes into the scene. The OneWeb constellation, as well as similar systems being produced by SpaceX, Boeing and others, promises to close the digital divide. An astonishing fifty-four percent of the world has no or bad internet access. The FCC noted that in 2016, thirty-four million people in the U.S., or ten percent of the population, lack access to broadband internet, and it is severely worse in developing nations, especially those in Africa. OneWeb plans to begin initial deployment of its satellites next year, with the desired constellation of 648 satellites operating in low Earth orbit by 2020. If successful, the constellation would be the largest in outer space and have the lowest latency. Most communication satellites have a delay time of 600 milliseconds, while OneWeb satellites have a delay time of thirty milliseconds, which would be unprecedented. The company plans to manufacture several satellites a week in partnership with Airbus. The satellites will be placed in an orbit of 1,200 km, which is closer to Earth than most other communication satellites. The satellites use new positioning technologies to provide reliable and global internet coverage with low latency, which is exactly what is desired by the industry.
With several new communication satellite constellations planned, the industry is going to experience tremendous growth over the next few years. A new era of providing digital services to the world has arrived, and it is better than ever. Everything we do that uses digital technology is powered by satellites, but over half of the world still does not have reliable internet access. I hope that OneWeb closes the digital divide and helps create a world with global digital access, which will be used for the benefit of all.