With the anticipated launch around 2030, 6G brings promises of the “internet of senses” and the “internet of everything” to the world. Proponents claim that communication experiences under 6G will include data transmission for all five senses – sight, sound, smell, taste and touch.
The rapid advances that are happening in wireless technology should enable 6G-supported applications such as advanced virtual reality, holographic communication and distributed artificial intelligence. Accordingly, 6G aims to merge the real and digital worlds and open up a host of opportunities for users across the globe. These human-centric use cases should be complemented by advanced sensing and machine-type communications. This can be used for controlling robots in hard-to-reach locations, earth observation and deep integration of sensing with communications, among other applications.
Moreover, 6G will build on the important work being done to bring 5G to the world. While it remains to be seen which 6G use cases will be realised, 6G will need to incorporate the full range of terrestrial and non-terrestrial technologies if its benefits are to be enjoyed by all. As all previous generations of wireless technologies have demonstrated, the use of non-terrestrial technologies is essential for maximising reach. This means that 6G standards must include terrestrial network and non-terrestrial network (TN and NTN) technologies from the outset.
The value of technology advancement ultimately lies in the benefits it brings to citizens. With researchers defining 6G as the “internet of everything”, key requirements have emerged for its users to have a meaningful, reliable and secure experience.
Satellite is key to making 6G a reality. While 5G optimises terrestrial network design to allow the integration of satellite for extension of coverage and availability, 6G will optimise network design, implementation and operation with consideration for the characteristics of both terrestrial and satellite communications, in order to create unified networks. Building on the integration of NTN with 5G, 6G will leverage the most advantageous characteristics of satellite communication and sensing systems.
Different types of 6G devices will be able to access satellite-based networks with service capabilities suitable for their specific use cases.
Role of satellites in 6G
6G will need to rely on the combined benefits of multiple communication technologies for its use cases to be meaningful to society at large. As such, with the key value integrators of satellite communications being ubiquity, continuity, scalability and resilience, it stands to play a central role in 6G networks. Satellites already play an important role in expanding the reach of 4G network services, and are poised to expand 5G network services as well.
The key capabilities of satellite networks that make them particularly well suited for delivering 6G are as follows:
Global coverage
Satellites connect all parts of the world, from the most densely populated areas to those that are otherwise unreachable. This includes providing mobility services on planes, ships and land-based vehicles, as well as their supporting infrastructure. Building on internet of things conceived around 4G, and further expanded in 5G to support NTN, 6G networks will link sensors everywhere to create internet of everything.
Due to their location in space and differing orbits, communications satellites are particularly well suited for distributing critical information in 6G networks over wide areas.
Sustainability
Satellite communications will support TN to address global sustainability goals. For example, satellites can provide communications directly to locations where the embedded carbon costs for a TN solution are too high. In addition, satellites should increasingly be seen as “base stations in the sky”, from where content and data can be accessed at any time, from anywhere. Moreover, they are reliant on solar power and thus do not require huge amounts of energy to run or cool them, as is the case with land-based data centres. Satellite communications can connect widely dispersed sensors used for essential environmental and climate monitoring, such as for providing early warnings for possible wildfires. They can also connect systems requiring large-scale energy to operate, such as railways, thus reducing operational energy requirements.
Reliability
The use cases revolving around unifying the physical, digital and biological worlds that are expected from 6G will require 6G networks to be highly reliable, resilient and secure. Some mobile operators have experienced first-hand how integrating satellite communication can significantly increase the uptime of their networks. This is due to the higher availability of NTN, so when unified, NTN and TN can maximise service reliability, for example by using NTN to provide a backup connection for the primary TN connectivity.
Resilience
With climate change and geopolitical tensions on the rise, the world is becoming increasingly susceptible to both natural and man-made disasters, while at the same time becoming increasingly dependent on connectivity. Leveraging the “always on” capability and inherent resilience of space-based networks, 6G networks are set to be the most resilient ones of all time, as long as they are conceived as unified networks from the start, building on 5G developments based on NTN and TN technologies.
Security and authentication
With 6G being hailed as the internet of everything, its users will rightfully demand an unprecedented level of security, trust and authentication. The inherent security features of satellite communications make hacking or eavesdropping on data transmission extremely difficult, particularly in point-to-point or private circuit operations.
As the capabilities of quantum computers grow towards building a stable environment offering reliable quantum supremacy that is able to break today’s encryption schemes in near-real time, the need for enhanced security and authentication will also grow. This includes securing 6G networks (including satellite communications networks) and delivering quantum resilient security-as-a-service, that is, quantum key distribution (QKD).
Satellite QKD may pave the way for a global quantum internet network, where satellite naturally addresses path length limitations arising due to fibre absorption.
Meeting capacity requirements
6G’s multi-sense data transmissions are likely to require significant capacity. Unlike the tenfold increase from 4G to 5G, there may be a hundred fold jump in speed, requiring extensive integration of technologies in order to support the anticipated demand. Placing this transmission load on terrestrial networks alone will put great strain on even the most advanced systems, thus affecting the quality of service and ultimately hindering the adoption of 6G. Accordingly, to meet these data needs, multiple networks will be required. Satellite connectivity can offer a competitive alternative to, or complement, terrestrial technologies by offering connectivity where it is not available, or additional bandwidth to ease bottlenecks and carry the extra traffic. All wireless technologies, including satellites, will need spectrum to function in the 6G ecosystem.
Positioning and timing services
The delivery of several services envisaged under 6G will require higher resolution, positioning and speeds than are available under 5G. This will enable position-dependent services related to the metaverse and sensing, while supporting higher fidelity quality of service and higher data rates for 6G. Satellite networks will need to support these requirements, as well as deliver them as a service in outdoor locations, for which they are perfectly suited.
Future outlook
The use of satellite systems can help accelerate 6G deployment. By encouraging terrestrial telecom operators to use satellite communications, nations can prevent rural areas from lagging behind urban ones in the adoption of new technology. They can also enjoy the advantages of connected populations and economies, avoid creating a 5G-6G divide, and meet development goals far earlier than expected.
With work on 6G already under way, it is critical that governments begin to consider the wide range of technologies that will be required to realise the vision. For 6G to be socially and economically inclusive, governments and regulators will have to ensure their policies and regulations are also technologically inclusive, so that all kinds of technology can function properly in the 6G ecosystem.
The building blocks for satellite-terrestrial integration have been put in place with 5G. 6G will build on these to deliver unified networks with inbuilt ubiquity, continuity, scalability and resilience.
Based on a white paper, “Satellite Communications and Their Role in Enabling 6G”, by the Global Satellite Operators Association
