What is a non-terrestrial network (NTN)?

A non-terrestrial network (NTN) is a type of wireless communication network used for applications such as mobile communications.

The term refers to multilayered networks linking terrestrial base stations, ships at sea, high-altitude platform stations (HAPS), and communication satellites in space. These characteristics allow an NTN to overcome the limitations of land-based networks, dramatically expanding the coverage of the communication infrastructure to include areas such as mountain valleys and areas of the ocean far from land.

Among non-terrestrial networks, this article focuses on wireless communication networks comprising elements at high altitudes, far above the land and the sea. R&D, test beds, and demonstrations are starting to be rolled out as part of plans for the development of non-terrestrial networks in the stratosphere and outer space in preparation for the advent of the next-generation telecommunications standard known as Beyond 5G (5th Generation Mobile Communication System, B5G)/6G (6th Generation Mobile Communication System).

From the stratosphere to outer space. Configuration and features of non-terrestrial networks (NTNs).

Different Types of Transmission Equipment in a Non-Terrestrial Network

As shown in Figure 1, a non-terrestrial network deployed in the skies above us would be composed of different types of transmission equipment for which higher altitude corresponds to wider coverage area. Naturally, the greater the distance from the Earth’s surface, the greater the signal delay, and the different types of transmission equipment will be used for different purposes depending on their location, in outer space or the stratosphere, or at ground level. This makes it possible to build a communication infrastructure with a wider coverage range than was previously attainable, such that we will be able to say that “nowhere on Earth is out of range.”

Below, we present an overview and feature description of the artificial satellites (GEO and LEO) and unmanned aircraft (HAPS) that compose the non-terrestrial network.