A joint effort is the best way forward for both terrestrial and non-terrestrial operators to deliver future services that can grow the connectivity landscape beyond ground to space and air.
Communications networks are one of the major forces driving the digital economy and world operations at large. The innovation of communications networks shows no signs of slowing down after nearly two centuries. Instead, the pace of maturation among connectivity technologies has been accelerated – from the evolution of 2G to 3G/4G and now 5G and ongoing preparation for 6G.
Gigabit optical home broadband, fiber, Wi-Fi 6, and other enhancements are enabling new use cases and scenarios for connectivity technologies, paving the way to a fully intelligent world.
An important aspect of this scenario is non-terrestrial networks (NTN). NTNs have a clear role to play in connecting the unconnected, with more trends and technologies that will emerge in a matter of when not if.
Significant improvements to cellular connectivity are expected with the development and introduction of smart antennas, low launch costs for low-earth orbits (LEOs), long duration of flights for high-altitude platform systems (HAPs) with appropriate control and distance, and protocol modifications for seamless integration.
NTN: Fundamental to 5G
Barriers to internet access, radio coverage, backhaul and power availability, and site building and maintenance are present in mountains, islands, deserts, weather extremes, and vast distances. In this case, wide-area coverage is likely to be possible from aerial or satellite platforms.
Earlier this year, satellite operators Intelsat, SES, and Kacific came to the rescue of the connectivity needs of Tonga, after the massive underwater volcanic eruption that destroyed the nation’s main subsea cable. In response, Intelsat provided space-based broadband connectivity on Horizons 3e and Intelsat 18, SES’ C-band capacity allowed residents to make international calls, while Kacific offered more than 1 Gbps of satellite capacity to Tonga’s telecom players.
This brings to light the relevance of non-terrestrial networks (NTN) in addressing the massive connectivity demands today. NTN has become an umbrella term for any network that involves non-terrestrial flying objects including satcom networks (LEO/MEO/GEO), HAPS, and air-to-ground networks.
Over the years, the world has witnessed resurging interest in the broadband provisioned by LEO NTNs with large satellite constellations such as Starlink, Kuiper, and OneWeb. To benefit from the economies of scale of the 5G ecosystem, the satellite industry has engaged in the 3GPP process to integrate satellite networks into the 5G ecosystem.
Following GSMA’s Release 17 inclusion of 5G NR support for satellite communications, satellite backhaul communications for CPEs and direct low data rate services for handhelds as well as eMTC/NB-IoT operation to satellite communications are testament to the mobile ecosystem’s resiliency and commitment to drive 5G forward.
Thus, the future of 5G networks is deemed to not only consist of the usual terrestrial networks, but a hybrid architecture of terrestrial and nonterrestrial networks providing ubiquitous coverage, network reliability, network capacity expansion, and extended reach of broadband to rural and underserved communities.
To define, HAPS are airborne platforms that can include airplanes, balloons, and airships while air-to-ground networks aim to provide in-flight connectivity for airplanes by utilizing ground stations which play a similar role as base stations in terrestrial mobile networks.
Saudi Arabia has facilitated the world’s first demonstration of the HAPS using aircraft to extend a 5G service, covering an area of 450 sqkm.
Another advocate of HAPS business development is Intelsat. “Connecting the unconnected is in our DNA. That’s why Intelsat is committed to a seamless, multi-orbit network strategy that includes exciting technology like HAPS. This will help extend our approach to the stratosphere and allow ubiquitous connectivity with traditional MNO networks and standards,” said Greg Ewert, vice president of strategy and business development at Intelsat.
For the benefit of both HAPs and LEO systems, advanced antenna technologies make it possible to turn a UAV or a LEO satellite into a 5G base station or integrated backhaul provider.
Challenges such as channel modeling, HARQ processes, synchronization, mobility, and constellation management ultimately come down to the antenna technology. Advanced intelligent antenna solutions like multi-channel and digitally phased array antennas (consumers) and dual parabolic antennas (enterprise customers) are essential to ensuring that NTNs are not only economically viable but also able to seamlessly integrate into terrestrial 5G networks.
NTN systems feature a terrestrial terminal, an aerial/space station, a service link between the terrestrial terminal and the aerial/space station, and a gateway that connects the NTN access to the core network. These can provide three-dimensional global coverage and latency of less than 100 ms.
For now, operating terrestrial networks (TN) and NTN in co-exist mode is not possible over the same frequency. Regulators are yet to decide whether a specific spectrum/band shall be used for either type of network. For higher frequencies (above 24Ghz), there is a possibility for co-existence with certain limitations that needs further studies and analysis for feasibility and implications.
With the development of 5G systems, satcom can reduce the deployment and operation costs of terminals and other network infrastructure equipment while being able to facilitate a tighter operational integration into a heterogeneous network of networks. Certainly, the ongoing standardization efforts around 5G provide a unique opportunity to insert NTN-based services.
Aside from the technological perspective, on business scope, NTN revenue opportunities include rural consumer broadband, rural business applications, automotive apps, industrial IoT services, end-to-end logistics and asset tracking, and remote health.
From one end to the other
In the long run, we would not be aware of whether we are communicating with a terrestrial tower or an NTN-based platform. Connectivity across borders will be achieved in a quicker, more reliable, and more affordable manner.
Moving forward, broadband coverage will extend beyond the ground as the evolution of wireless connectivity encompasses the air and even space, connecting devices at various heights and levels.
With NTN, particularly satellites, the long haul and last mile are one and the same, eliminating failure risks by having a single end-to-end network provider that owns, operates and controls every portion of the network and can diagnose and fix problems unilaterally.
On a bigger scale, heterogeneous networks would involve operators who are already providing wholesale offering to MVNOs on their network. In line with this, the terrestrial network would have a direct relationship with satcom providers. The alternative access network provider then becomes a wholesale operator, offering roaming services or network as a service (NaaS) for better efficiency, agility, and flexibility.
