The 6G series: Why it’s a great time to start talking 6G

Unbeknown to most people outside our industry, it takes about a decade to design a new mobile generation. It takes so long because many corporates, regulators and global standards bodies need to agree on minute technical designs and implementations. The upside: you can buy a smart phone in Europe that is manufactured in Asia with a SIM card from the US and call your Australian friend who is on a safari in Africa whilst you are hiking in South America. It “simply” works!

With 5G largely designed and now being deployed worldwide, it is thus a great time to start talking 6G! There are many unknowns still when it comes to choices of specific 6G technologies and architectures, as well as use-cases which cannot be embodied with 5G and the general 6G regulatory landscape. However, given it will take us many years to design, the right questions are better posed today.

Based on prior material published by us Ericsson as well as the wider ecosystem, we decided to launch a regular thought-leadership series on 6G where we will share our insights and achievements but also open up on issues for which we need help from the wider academic and industry ecosystem.

Above: 6G can enable a programmable world with new possibilities for technologies such as holographic communication and connected intelligent machines

First Technology Steps towards Societal Use-Cases

In Ericsson, we have identified several societal use-cases that require 6G as an underlying connectivity solution:

• (Human-centric) Internet of Senses: We envisage a holographic society in the future where people form emotional bonds over long distances through highly immersive and immediate holographic projections, which might even be augmented by touch. The expected uplink and downlink data rates, connectivity ranges and latencies cannot be offered on a wide scale by today’s 5G networks. In addition, advances in security and privacy will be required from 6G.
• (Machine-centric) Connected Intelligent Machines: More and more machines are being connected through the growing Internet of Things (IoT), a trend which will continue into the 6G era. We envisage machines not only to transmit their sensor data but to outsource their intelligent decision making, thus requiring substantially more powerful networks to cater for that exponential increase in data traffic and reduction in required and consistent latency.
• (Environment-centric) Programmable Physical Worlds: As already discussed above, an important paradigm shift will emerge over the years to come in that sensing and intelligent decision making will be augmented by actuation in real-world environments. That allows us to reconfigure physical environments in real time according to needs which can prove useful in industrial, enterprise and consumer industries.
• (Sustainability-centric) Connected Sustainable World: We believe that all of the above ought to be underpinned by technical and policy solutions which promote sustainability and Net Zero carbon emissions.

As illustrated in the accompanying figure and discussed in Ericsson’s 2022 6G white paper, we believe that the above use-cases will be enabled by four key technology areas:

• Limitless connectivity: It embodies the notion of having reliable networking connectivity, catering for extreme performance and coverage when and where needed. It requires novel radio architecture approaches as well as new 6G spectrum.
• Network compute fabric: It pertains to the notion of “flattening” the compute fabric in that developers of the future won’t need to think about where to place the applications. It is rather the digital fabric, i.e. the end-to-end architecture, which takes that decision. For instance, if an app needs extremely low latency then it will be placed closer to the edge with the digital fabric natively providing the means, i.e. compute, storage and orchestration.
• Cognitive networks: This capability refers to AI becoming a native ingredient in future networks. It allows networks to become automated and even autonomous, thus exhibiting cognitive properties that hide the increased network complexity from the users.
• Trustworthy systems: Users in the envisioned societal use cases must be able to trust the networks to perform according to expectations. This puts requirements on security, reliability, resilience, safety and privacy of the networks – thus protecting data and mitigating various kinds of attacks and disturbances, intentional or unintentional.

Above: Expected use case- and technology scenarios enabled by 6G

Regulatory, Standards and Industry Timelines

The above use-cases will need to be translated into standardized technologies. Illustrated in the accompanying figure, the timelines for 6G are (likely) as follows: basic academic research started as early as 2017; various 6G alliances were formed as early as 2019; the ITU process started in 2021; first standardization work will be published in a few years from now and commercial roll-out is expected later this decade. Let’s examine each in more detail.

Above: The overall 6G timeline – from research phase to commercial deployment

Basic academic- as well as applied industry 6G research is paramount in addressing some of the hard design challenges, particularly pushing the limits in terms of understanding fundamental system limits, novel materials, innovative protocols and scalable architectures. We will outline some important challenges, as well as first technology solutions below as well as in subsequent 6G blogs.

In terms of 6G alliances, their importance cannot be stressed enough. A major success outcome of mobile systems is the general interoperability which is achieved through the entire industry participating early in a reconciliatory process towards a harmonized architecture. Ericsson participates in most global initiatives and has strongly influenced the development of leading white papers, such as for EU Hexa-X, US NGA, or the global NGMN. The alliance work over the past months has enabled us to obtain a globally harmonized understanding of 6G use-cases, and how they differ from 5G use-cases.

These use-cases are now being submitted to the ITU which translates these into technical KPIs in terms of required data rate, latency, number of devices, energy efficiency, among many others. Similar to 5G and 4G before that, the idea is that the ITU will eventually publish a document outlining the minimum technical specifications of 6G. Any system able to achieve these KPIs through rigorous standardization processes will obtain the label 6G.

Any qualified standard could in theory design the next generation mobile system but – more likely than not – it is expected that 3GPP will lead the standardization of 6G, complemented by other forums such as O-RAN. The reason is that it has a lot of experience from designing 3G, 4G and now 5G; enjoys a huge industry backing and has the global scale to ensure a harmonized approach. An important aspect though is that 3GPP does not tick in generations but rather in releases, which are substantial technology changes/improvements captured in thousands of pages of standards documents.

Illustrated in the accompanying figure, Ericsson’s view of the 3GPP planning is shown together with the agreed ITU-R timeline. Based on past design cycles, it is likely that 6G will commence with a requirements study item (SI) in release 19 and then be developed through technical SI’s and work items (WIs) in releases 20-24.

Above: Our view of the 3GPP timeline mapped to the agreed ITU-R timeline

A parallel yet equally important process pertains to ensuring spectrum availability for 6G, which can be achieved in different ways; through ITU World Radiocommunication Conferences, regional decisions or decisions on a per country basis. Whichever method is pursued, harmonization of the selected frequency bands on a global (or sometimes at regional basis) is key to unlocking economies-of-scale and providing numerous benefits to consumers and enterprises across many markets.

Considerations of additional spectrum for 6G have already started in a number of countries and regions.  The ITU conference taking place every 4 years, with the next one – WRC 2023 – scheduled at the end of 2023 is another important milestone. Given the 4-year gap between WRC events, the decision cycles are very long – often in the order of a decade. It is thus hugely important to identify any spectrum needs as early as possible so that enough spectrum can be made available for 6G when it is being switched on at the end of this decade.

Another aspect to consider is that the introduction of 6G and new spectrum may raise questions about its safety. For instance, in the early days of 5G, misinformation was spread about health risks related to the radio waves being used by the new networks which made some people concerned. This was mainly because consumers were oblivious to the existence of science-based safety standards and the rigorous testing work which is required before new radio equipment is placed on the market and put into service. To prepare well for 6G, even more effort should be put early on to communicate about the safety of the new networks and how they greatly contribute to societal benefits.

Some Important 6G Design Challenges

Equipped with a solid understanding of 6G use-cases and design timelines, we are in a good position to explore some of the holistic design challenges (understanding that the list is not exhaustive).

From physical and digital worlds to a cyber-physical continuum

A few years ago, Ericsson laid out an exciting vision for a technology future composed of a cyber-physical network platform that should not only connect humans and machines but be able to fully merge realities to allow seamless interaction and immersive experiences continuum.

This was well before the ecosystem started talking about digital twins or the metaverse!

Here, vast numbers of sensors embedded in the physical world send data to update the digital representation in real time. The data is transmitted via networks that provide connectivity and thus full synchronization between the two worlds. Actuators in the real world then carry out functions that are programmed in its digital representation.

Whilst visionary, the notion of a digital world capturing the physical world and the physical world being re-programmed by a digital world yields significant design challenges: technical issues of scale, reliability, security and privacy need to be solved. For instance, any (robotic) control reconfiguring the real world needs to ensure that it is stable and aware of human presence; or, any data collected, needs to ensure that it has been privacy vetted.

Above: 6G could unleash a new cyber-physical continuum

Spectrum enabling global (3D) connectivity

Another important challenge is to enable the transition from terrestrial 2D to global 3D connectivity – aiming at full digital inclusion, powering advanced cloud-rendered XR use-cases such as holographic communication, and reaching for limitless connectivity in rural land, sea, and even air.

Both existing and new spectrum bands are thus needed in the 6G era! Without the additional spectrum, we will not be able to address the demands of future 6G use cases. We have thus identified new potential spectrum ranges for 6G, notably in the centimetric range from 7-15 GHz, which we believe will be an essential range, and in the sub-THz range from 92-300 GHz, which will have a complementary role serving niche scenarios.

Above: 6G will require a new spectrum range

Our learnings from 5G are that the mmWave range is a powerful spectrum range which allows operators to provide value to industry and enterprise through high data rates. However, due to limited coverage, it serves as a complement to other ranges that can be used in wider areas but with limited data rates (i.e. mid bands).

We believe that in order to benefit society, the majority of 6G use cases should be enabled for wide-area coverage, both indoors and outdoors, and not limited to confined areas. This means that – whilst we ought to explore the sub-THz region for entirely novel 6G capabilities – the main value will be in the centimetric 7-15 GHz.

From energy efficiency to sustainable transformation

Sustainability has become a central theme across all industries, and the mobile industry is no different with the realization that resource-efficient networks impact society and enable environmental footprint reduction through effective digitalization.

Research from 2018 estimates the ICT sector’s carbon footprint to be 730 Mt CO2-equivalents or 1.4% of overall global emissions, and the sector uses 800 TWh or 3.6% of the global electricity for its operation (based on 2015 data).

We ought to continue with the success from 4G and 5G systems, where network energy consumption has been decoupled from data traffic growth. It will underpin the ICT industry’s Net Zero ambitions as well as effective digitalization of the society. Energy efficiency will thus need to be a prime design driver in 6G networks – at par with data rate and latency!

As a result, end point devices – such as IoT sensors or MTC actuators – may need to be redesigned to allow for zero-energy consumption where the energy required for communications is scavenged from the environment through, for example, RF, vibration or light. This requires a redesign of the underlying material / digital fabric used, e.g. towards neuromorphic compute. Also, transceiver chains, signal processing, and power control mechanisms need to be redesigned.

Another aspect is to work towards carbon-neutral networks where naturally available energy resources are used to power the network operations. This may require a redesign of the air interface and various RAN functions so that the system is optimized for asynchronous energy availability.

As part of an upcoming series of 6G blogs, we will discuss technical aspects in more detail. We will outline design challenges and propose engineering solutions which will allow us to develop powerful yet pertinent next-generation 6G mobile systems.

Join us on this exciting 6G journey!

Learn more

Explore Ericsson’s journey to 6G.

Explore our library of 6G blog posts.

Read our 2022 6G white paper: connecting a cyber-physical world.