This is the second blog in a series on Non-Terrestrial Networks. You can find the first one here.

In our previous blog, we highlighted how innovative Non-Terrestrial Networks (NTNs)—wireless platforms that operate above the Earth’s surface using satellites, drones, and other airborne vehicles—are impacting communications and transforming the way both humans and machines interact on a global scale.  

This profound change, which has the potential to deliver communications anywhere and everywhere, is being driven by several different pillars of innovation, each of which is essential to supporting the growth of NTNs. The first of these pillars is the convergence of several technologies, including space systems, advanced computing, and AI. The second is the drive to facilitate interoperability, or the ability of NTNs to work with one another and with terrestrial networks. By acting together as one unified “3D network”—the industry’s terms for a seamless connectivity experience—they can keep devices constantly connected while making the complexity involved invisible to users. The third and final pillar focuses on innovations in areas such as hardware and spectrum-management that are key to helping NTNs scale effectively and meet performance demands. This blog examines each of these in more depth. 

A trio of technologies turbocharging NTNs 

Innovation and competition in the burgeoning commercial space economy are benefiting companies creating NTNs by significantly lowering the cost of launching satellites and their payloads. Starlink alone has launched over 5,000 satellites to date for its constellation, and competitors such as Kuiper and OneWeb are planning to launch their own constellations that will add thousands more satellites. Moreover, newer space industry business models provide satellite and ground terminal infrastructure as a service in addition to launch capabilities, allowing NTN providers to outsource much of the complexity of launch and space operations, and enabling them to focus on creating differentiated services. The growth of drones and other aerial platforms is another driver, though use of them for wireless connectivity hasn’t yet taken off in the same way that satellite-based NTNs have.

Another force multiplier involves advancements taking place in the microelectronics industry. Managing complexities like controlling active antenna arrays on satellites and other platforms to facilitate connectivity and optimizing use of wireless spectrum is a big challenge given that some of these platforms may be moving very fast in the air or in space. To ensure calculations can be made at the point where action can be taken immediately, much of the data processing associated with NTNs therefore needs to be done on satellites, drones, equipment at ground stations on Earth, and even on people’s smartphones rather than in, say, cloud data centers.  

Innovations in semiconductor design and manufacturing as well as other aspects of microelectronics are helping to deliver the necessary on-device compute power needed by NTN operators, who are also tapping AI to automate tasks and to continuously adapt and improve performance. Many different AI models are being deployed to boost wireless network efficiency in areas such as energy consumption, spectrum usage, and general network operations. 

E Pluribus Unum for NTNs

Latin for “Out of many, one”, the motto from the Great Seal of the United States could also serve as useful shorthand for what developers of NTNs are aiming to achieve, which is to deliver a seamless experience for users by knitting together multiple kinds of networks, both terrestrial and non-terrestrial, to create 3D Networks. NTNs come in various forms, which are broadly categorized in the table below: 

Each of these platforms excels in certain situations and managing how they and traditional terrestrial infrastructure, such as cell towers, work together is key to transforming communications. Imagine in the future traveling across the world and your phone connects to cell towers when you’re in a busy city, but as you head to more remote regions it automatically switches to satellite networks to ensure continuous connectivity. Or imagine that a natural disaster disrupts terrestrial wireless networks, and then a HAPs or a LEO platform automatically kicks in to provide backup high-bandwidth connectivity.  

This quest for interoperability is full of challenges including (but not limited to) balancing open versus closed NTN ecosystems, achieving common standards, and driving technical innovation. Managing interoperability across networks will require many of the innovations turbocharging NTNs mentioned above. It will also necessitate advancements in other areas such as free space optical links (FSOL), or laser crosslinks, that can connect NTN constellations together. FOSL enable improved satellite-to-satellite connectivity, while avoiding the need for ground stations on the Earth’s surface, by pulsing lasers at high rates between constellations. The ability to control the lasers’ direction precisely and their ability to handle high rates of data transfer make them a secure and capable solution for linking NTNs together.  

Developments in industry standards for spectrum use should also facilitate greater interoperability. Currently, NTNs and terrestrial networks function pretty much independently of one another. But there are efforts under way to encourage adherence to industry standards that will make it easier for the different types of networks to work together. For instance, 3GPP, a collaboration between telecommunications organizations to develop technical specifications for cellular standards (including 4G, 5G and future standards) began including NTNs in its Release 17, which was formally launched in 2022.   

The challenges of scaling

The proliferation of aerial platforms that can support NTNs, advances in microelectronics and AI that can deliver powerful edge computing capabilities, and efforts to boost interoperability are all key to the future success of the NTN field. So, too, are efforts to create more scalable operational models, which are accelerating moves to shrink hardware and create more efficient ways to use relatively scarce resources such as spectrum.

Demands for higher-performance user equipment in smaller and more convenient form factors are already delivering results. For example, Starlink just announced the Starlink Mini, a ground terminal that’s small enough to fit into a backpack. Another example of innovation here is the current push by many companies to enable direct-to-cell connectivity from NTN platforms (as opposed to via ground links). While initial demonstrations have involved the transfer of a small amount of data from satellites to phones, efforts are already underway to introduce voice calls and video as well.  

When it comes to spectrum, the frequency bands available for satellite communication are finite—so to scale effectively NTNs will need to use existing spectrum more efficiently, as well as expand the amount of spectrum available by scaling to higher frequencies. The former will require efforts to identify more advanced waveforms that enable more data to be packed into an existing frequency band, as well as enable efficient communication at these higher frequencies. These technical challenges make the design of communications components for NTNs—such as antennas, power amplifiers, and receivers—more difficult in literally every way, including requiring even greater precision in manufacturing and the development of more efficient ways to dissipate heat from equipment.  

The very encouraging news is that we’re already seeing innovation across the board aimed at addressing these and other issues. Novel waveforms have been identified, and novel antenna materials and designs have been developed to push the industry forward. Architectural and material innovation in radio frequency components also hold out the promise that NTNs will be able to scale to meet industry demands for efficient and cost-effective connectivity.  

All of these innovations will drive significant advances in the future—and those advances, in turn, will have important implications for both economic activity and national security. We’ll explore these crucial dimensions of the NTN revolution in the third and final blog in this series.