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Non-Terrestrial Networks: What They Are and How They Drive Innovation Towards 6G

April 18, 2024

Terrestrial, airborne, and satellite wireless communications have existed independent from each other for decades. With the advancements of cellular telecommunications, we are now beginning to experience convergence across these three landscapes to support the capability to beam 5G signals down from non-terrestrial platforms to augment and support our terrestrial telecommunications infrastructure and devices. The importance of these “Non-Terrestrial Networks” (NTNs) will grow as they offer “anything, anytime, anywhere” connectivity – promising to enable seamless “global” wireless connectivity as we evolve from 5G to 6G.

The idea for NTNs isn’t new.

What is new, however, is the need for integration and orchestration across satellite, aerial, and terrestrial networks to jointly improve and provide heterogeneous network connectivity. The partnership announced between SpaceX (using their Starlink satellite constellation) and T-Mobile in August 2022 for satellite cellular direct-to-device (or “direct-to-cell”) connectivity spurred a wave of activity across startups racing to provide NTN connectivity.

In this blog, we’ll explore what NTNs are, their importance to the global market, and how their growth and intersection with 6G will bring new national security challenges. As one of the most active strategic investors in both Telecommunications and Commercial Space Technologies, IQT believes that both the government and the commercial sector have a role to play to drive innovation for NTNs and the future of cellular telecommunications.

What are Non-Terrestrial Networks (NTNs)?

NTNs are wireless communication systems that operate above the Earth’s surface, using platforms in low to high altitudes and extending into space via satellites.  These platforms augment terrestrial networks to bring seamless and global coverage – even in remote and austere environments where terrestrial infrastructure is challenged in their deployment. These NTN systems offer high data rate and low data rate capabilities for a variety of applications. High data rate applications range from providing backhaul to terrestrial equipment that is difficult to service to wireless access to mobile equipment and platforms in maritime, terrestrial, and airborne environments. Low data rate applications include direct-to-cell SOS and two-way messaging in remote areas to Internet of Things (IoT) asset tracking and remote monitoring.

It is important to note, NTNs will augment and not displace terrestrial networks. The commercialization of space has been critically importantly as the underlying ecosystem to support the proliferation of space-based NTN assets, and airborne NTN platforms still face several technological barriers for sustained operations to support NTNs. While the platforms are critically important, the continued growth of NTNs requires a deep technical stack and innovative solutions to overcome multiple technical challenges for their operation and sustainment. Figure 1 below depicts the evolution of commercial NTNs. A few of the critical enabling technologies are the software and algorithms needed to orchestrate connectivity between NTNs and terrestrial networks, and the use of artificial intelligence to improve the performance and efficiency of both terrestrial networks and NTNs.

Figure 1. Evolution of Commercial NTNs

NTNs expands legacy cellular and advances 6G globally.

NTNs are defined as part of 5G Advanced, an evolutionary step in 5G technology bringing enhanced capabilities and supporting a wider set of enhanced use cases. Use cases that require the operation in austere environments where significant cost and technical challenges prevent terrestrial networking, such as mining, oil and gas, maritime, and transportation and logistics would benefit from efficient, reliable, resilient, and interoperable connectivity. But NTNs should also be seen as a longer-term strategy for crafting a vision for 6G and the global scale of trusted communications infrastructure that is based on the premise of openness, interoperability, and competition. 

Today, NTNs are an important gap filler supporting legacy cellular expansion. For example, NTNs backhaul capabilities enables the efficient deployment, in both cost and complexity, of legacy cellular technologies (i.e., 2G through LTE). In the future, NTNs will be highly integrated and unified with terrestrial networks. This will provide ubiquitous coverage with high data rate communications at low latency and a growth of new services and capabilities, including highly accurate and reliable location services and integrated sensing.

China’s Huawei quietly dominated the Radio Access Networks (RANs) for 4G/LTE and emerged as the global leader for 5G. These RANs are the telecommunications equipment that wirelessly connect our devices today and have been part of China’s central strategy to dominating how the world communicates. Twenty years ago, close to two dozen big companies, including American firms, supplied global telecommunications equipment. Today, majority foreign firms sell into this market and is dominated by China’s Huawei. NTNs growth and promise of convenience and new capabilities will rely on existing and future RAN technologies. At present, NTNs are largely dominated by U.S. entities, but China has ambitions to create its own NTN infrastructure that would be further integrated with their Belt and Road initiatives.

IQT sees NTNs playing an outsized role in the future of 6G. Open Radio Access Network (ORAN), is one architectural approach for 5G supporting modular and virtualized mixing and matching key telecommunications components, has been slow to adopt, but has recently seen tailwinds of success. While satellites too are closed and proprietary platforms and systems, the emergence of NTNs to the global telecommunications ecosystems will require interfaces, technology, and architectural developments to support diverse interoperability – achieving many goals aligned with ORAN. The adoption of ORAN, or at least the implementation and agreement on open interfaces and extending these open interfaces to NTNs, enables co-operation and orchestration between terrestrial networks and NTNs. In doing so, this enables a future supporting ORAN objectives at global scale, while also accelerating 6G deployments – enabling scalability and security for the future of global telecommunications.

The Role Innovation Will Play

Today, the market for 6G products and services is small, with few companies thinking about how their technology applies. With 6G marketed for operation in 2030, companies will continue to focus on near-term revenue generating opportunities. However, the market for NTNs is steadily growing. The advent of Starlink has marked a significant milestone for the deployment and growth of commercially accessible NTNs. Over the past year Starlink has also made a mark on the importance of NTNs, and more generally the importance to modern government-based communications and operations (e.g., Ukraine). In addition, Apple’s introduction of SOS via NTNs for their iPhone demonstrates “big techs” embracing of this technology.

IQT believes that NTNs will continue to grow over the next two to five years. This growth will demonstrate its importance to its role for the future of 6G. NTNs will become a major part of the global telecommunications infrastructure augmenting and interoperating with the terrestrial cellular network. While 6G is still far away, now is time to demonstrate leadership by investing in technologies and capabilities supporting 6G growth and align U.S. national security objectives to counter China’s control of the current telecommunications ecosystem. NTNs is one important aspect, but there will be a myriad of additional technologies required. Stay tuned for more NTN on our blog throughout the year as we discuss the impact the technology will have both commercially and on national security.

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