5G is widely touted as a gamechanger in mobile broadband services in terms of data speeds, low latencies and massive connectivity features. And it is. But there’s far more to the disruptive power of 5G than fast speeds – it’s also about the resulting network architecture that brings new levels of flexibility and service innovations the mobile industry has never seen before. 

5G’s future is hybrid – the non-terrestrial opportunity

My view, and the subject of our latest whitepaper, is that the rise of 5G will be accompanied by the rise of non-terrestrial networks (NTNs), which includes high-altitude platforms (HAPs) such as unmanned aerial vehicles (UAVs) and low earth orbit (LEO) satellites. These NTNs will be integrated with terrestrial networks to create a hybrid terrestrial/non-terrestrial 5G mobile infrastructure serving consumers and enterprises. 

Why are NTNs gaining traction now? 

LEO satellites are well established. Iridium Communications launched the first such network in the late 1990s, and has recently completed a $3 billion satellite constellation upgrade to provide global coverage of its latest services. A number of new LEO projects have also emerged in the last couple of years with the goal of providing further connectivity to every point on the planet. 

LEO constellations are gaining traction thanks to a number of factors, from innovative satellite designs and cheaper launch costs to advanced electronics and antenna capabilities. 

HAPs – in combination with larger scalable antennas – are a more recent development. Such platforms come in various forms, including balloons and aerostats. For me, the most promising platform for HAPs connectivity is UAVs, which fly at a higher altitude (around 60,000 to 80,000 feet, which has the benefit of stable weather and no commercial air traffic to contend with). UAV platforms benefit from advances in automation, intelligence and energy, enabling them to fly almost autonomously for weeks at a time. HAP-based networks are designed to provide connectivity services that can be integrated into terrestrial cellular services in areas with no ground infrastructure. 

The innovation enabling hybrid terrestrial/NTN architecture 

For both HAPs and LEO systems, the key ingredient to the hybrid terrestrial/NTN architecture is the development of advanced 4G and 5G antenna systems that have pushed the area of beamforming and phased arrays forward significantly. A commercial 4G or 5G antenna today features 64 antenna elements. However, new antenna technology has been developed that can transmit hundreds of beams simultaneously that can be narrowed so finely and accurately that it’s the equivalent of one user having their own personal cell site. We discuss NTN antennas in more detail in the whitepaper, but suffice to say that advanced antenna technologies make it possible to turn a UAV or a LEO satellite into a 5G base station or backhaul provider that can be integrated into terrestrial 5G networks. 

The value is in the economics 

The development of advanced antenna and wider technology innovation gives me confidence that LEOs and HAPs will both have their place in the future 5G ecosystem, determined by the economics and the expectations of the users and the service to be provided. For example, HAPs will typically provide connectivity over a specific rural area with a population density that is too low by terrestrial standards to economically provide cellular services, but large enough to justify deploying a HAP to serve that area. HAPs can also communicate with standard devices and allow seamless roaming between networks. 

Meanwhile, LEOs will be able to serve areas with much lower density populations because the constellation coverage is global by default. Even though LEO bandwidth will be somewhat lower than terrestrial connectivity due to power, distance and signal constraints, such systems will still enable previously unreachable populations to get online with sufficiently fast connections. 

An evolutionary path  

Of course, we are not there yet. Just as 5G will evolve from its current incarnation to the full promise of gigabit speeds and millisecond latencies, NTNs have their own evolutionary path to pursue before full integration can be achieved.  

However, the enabling trends and technologies for this hybrid 5G architecture are coming together at a rapid pace. If you are interested in finding out more on the technology and antenna innovations that are enabling hybrid terrestrial/non-terrestrial 5G networks, then please read the new paper we have just published with the GSMA - 5G’s future is hybrid – the non-terrestrial opportunity

Author
Dr. Derek Long
Head of Telecoms & Mobile

Derek leads our collaboration within the telecoms and mobile sector, helping create breakthrough innovations that transforms the delivery of high-performance communication - for mobile carriers and ISPs to vendors and component manufacturers. With over 20 years’ experience in mobile technology, Derek has held a range senior management roles with multinationals and has a wealth of expertise across all generations of mobile and broadband technology, including LTE-A and 5G. Derek holds a PhD in telecommunications from the University of Bristol.