8. Terrestrial v Satellite

Today, I would like to review some of the latest communication technologies, namely 5G and LEO-satellite connectivity. I guess I just like space technologies too much. In the past, I have already discussed what I believe, are the two main issues 5G is facing, lack of infrastructure and vision. You can check my post on the topic here. Conversely, LEO-satellites are relatively new, not technologically but commercially instead. But before discussing the advantages and disadvantages of each system, let’s briefly review each technology.

5G (terrestrial) connectivity

5G refers to the fifth generation of mobile connectivity. It’s called terrestrial because it physically requires antennas on the ground to operate. It represents an increase in data transfer speeds, reduction of latency, and the capability to connect a massive number of devices to the network. The latest 5G standard developed by 3GPP considers three main areas of implementation.

  • Enhanced Mobile Broadband (eMBB) which mostly targets traditional mobile users. Depending on the infrastructure available, the consumer will see increased data transfers speeds of up to 1.8 Gbit/s (25 times faster than the average Wi-Fi speed).
  • Ultra-Reliable Low-Latency Communications (URLLC) which will target mission-critical services, such as telemedicine, military applications, and time-sensitive operations. It virtually guarantees reliability and immediacy of the connection.
  • Massive Machine-Type Communications (mMTC) which will provide an accessible and low-requirement link for smart devices operating in the Internet of Things. Such implementations will consume less energy to maintain communication through longer distances.

Apart from these implantations, the 5G software-based standard should be able to modify its parameters through software updates, creating the possibility of network slicing; this is the creation of multiple “virtual network” using the same hardware. Network slicing enables improved layers of configuration, privacy and cyber-security. Even the upcoming technical specifications for 5G, consider the integration of satellite communication as part of the standard.

Satellite connectivity

Satellite communication for voice calls and internet access is nothing new. However, until the past, the satellites used for this purpose were located in Geostationary Earth Orbits (GEO). New telecommunication ventures are looking at Low-Earth Orbits (LEO) to address the limitations of GEO satellites. But before describing the new projects already in motion, a brief description of these two types of orbits.

  • Geostationary orbits (GEO) refers to an orbit that rotates around the Earth at the same angular speed. Thus, from Earth the satellite appears stationary, hence the name. I will spare you the orbital mechanical lecture on how is that possible. For now, suffice to say that GEO satellites need to be far from Earth to stay in sync. About 36,000 km away, that’s about three times the diameter of the Earth. At that distance, even light take a bit to arrive. A return trip between Earth and a GEO satellite takes 400 ms. For comparison, humans start noticing the offset between the audio and video of a movie at 200 ms. The main reason for using this type of satellites is the larger area they cover. You only need 4-6 satellites to cover the entire Earth.
  • Low-Earth Orbit (LEO) refers to the orbits closer to Earth, between 500 and 1,000 km away. For comparison, the International Space Station is orbiting Earth at an altitude of 400 km. Due to their proximity, LEO satellites can relay communication much faster. The trade-off is that companies need many more satellites to cover substantial areas. For example, OneWeb’s constellation is considering 650 satellites; Starlink’s constellation, a SpaceX venture, is looking at least 12,000. These large numbers increase not only the coverage but also the network capacity, as each satellite can manage a finite number of clients. Finally, apart from the massive initial investment required to launch such ambitious constellation, there are substantial technological problems. Perhaps the more challenging is the hand-over issue. Given their proximity to Earth, these satellites need to travel very fast. A client device will need to change from one satellite to the next every few minutes, as these are steadily moving across the sky.

Terrestrial v Satellite

Now, although it is possible to compare the technical specifications of these two types of communication—such as data throughput, coverage or cost; the business logic behind these two technologies couldn’t be more different. It would be like comparing a chain of supermarkets (5G), that offers a wide range and volume of products for a large population, with a new company looking to bring drinking water to underserved communities (Satellite). Yes, it is that contrasting. 5G offers upgrades that, no doubt, will increase the capacity, productivity and efficiency of already digital organisations and customers. In contrast, satellite looks to provide high-quality connectivity to small and scatter populations. A key figure to remember is that up to the end of 2019, there were around 4.5 billion active internet users. That leaves more than 3 billion people underserved, without even considering migration of other users and the myriad of new business opportunities. If these new companies could serve a portion of these markets, it would represent a great success, as more people would be able to contribute to their societies and economies.

LEO Satellite constellation

Indeed, this is a great opportunity; however, it is not without its comparable risks. Mainly, the cost to set up the infrastructure, surpass the technology challenges, and develop a compelling commercial offering. Various companies are exploring diverse strategies. SpaceX, for example, is vertically integrating the entire supply chain, from the manufacture of the satellites to the launching and in-orbit operations, to the management of the communication network. OneWeb, who seems to be in the clear now, is seeking to leverage the UK government ambitions to create a more comprehensive ecosystem. Other incumbents and newcomers are also interested in venturing to this exciting industry. For now, only time will tell who would be the winners of this race.

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