THE POWER OF 6

With expected download speeds approaching 1 terabit per second, one microsecond latency, and unlimited bandwidth, 6G will enable ingenious ways for people to interact not only with each other, but also with their surroundings and for machines and systems to interact with each other too. This might include instantaneous communication, connected robotics and autonomous systems, and wireless AI interactions. To understand more, we asked Roger Nichols, Keysight’s 6G programme manager, about what is needed to make the vision of 6G a reality


What is 6G, and what is its biggest application opportunity?

4G gave us the mobile internet and enabled the smartphone. 5G will allow for use-cases that go beyond the smartphone into industrial, healthcare, transportation, and finance. 6G consolidates mobile wireless communications - no longer as a novelty or a special set of use-cases, but as an integral part of society. The use-models range from holographic communications that include information beyond sight and sound, to making digital twins far more sophisticated and thorough, to changing the way that we leverage data through machine learning (ML) and other forms of artificial intelligence (AI). There is also an intent to leverage 6G for sophisticated emergency and disaster management, as well as huge scientific applications. Much of what is being described today looks like “5G, but better” and some of that will be the case. We will see new use-cases evolve from the advancements of 5G that while being “introductory” in 5G, will become mainstream in 6G. These will have to do with systems that are more flexible, more efficient, and can intelligently handle orders of magnitude data. 6G will make two advancements on time-sensitive networking. First, the maximum latency KPI for critical applications for 6G is as low as 100 microseconds. This will have a significant impact on new use cases that are not just about getting information there quickly, but also leveraging for location-based services that are more precise. Second, is the concept of a minimum latency requirement; in other words, precise timing of information transfer even if the latency is long. Some information can arrive too soon to be useful, so time-engineering in networks means knowing that a message may arrive before a certain amount of time passes, as well as the ability to plan exactly when the information will arrive.

How will 6G impact daily life?

6G is about mobile wireless being an integral part of society. One could argue that this is the case with 4G, but most societies adoption of 4G is constrained to entertainment and advertising. So, think of mobile wireless as being a fundamental part of driving to work, making your evening meals, educating your children, gaining access to your health care needs, shopping, banking, mining, manufacturing everything from staples - to paint - to jet aircraft engines, and research in all fields, the list goes on. Think of what it was like in 1905 when Charles Howard couldn’t sell a single car in San Francisco. Now, the automobile pervades life.

Who or what will be the breakthrough driver for 6G?

What will make a difference in the success of 6G as a technology generation will be a few key elements. First, a single global standard is necessary for scale and consistency. 5G is the first example of a generation developed with no competing standard. For 6G to be a breakthrough, the industry should not allow geopolitical tensions to create work on a standard that splits into competing technologies. Second, the research happening now must yield affordable technologies for use during the evolution of 6G from the late ‘20’s to the late ‘30’s. Lastly, the advancements in security technology must keep up. Without high levels of trust in the system, “an integral part of society” will never manifest. Most are targeting a 2030 commercialisation timeframe. Like 5G, we could see commercial launches happen before the turn of the decade. This will be determined by that magical mix of technology, policy, and business model. In any case, like all previous generations, commercialisation will start from small regional implementations to nation-wide networks with all the fits and starts of any new system. Also, like 5G, the first manifestations of 6G will be a far cry from today’s vision - we are a good five years away from seeing 5G in full, based on vision-setting that was completed eight years ago.

What are the biggest challenges to move into the 6G era?

There are several technical challenges that span the five areas of technical investment: next generation radio, integrated multi-heterogeneous technology networks (ITU’s ManyNets), time-engineering in networks, AI-enabled and optimised networks, and next generation security. There are enormous challenges in each of these areas. The following are a few examples:

Roger Nichols

Next-gen radio

The move to 100-330GHz as carrier frequencies and information bandwidths of up to 30GHz (some have suggested more). These bands and bandwidths come with a set of issues analogous to those that confronted (and to some extent still confront) the 5G Frequency Range 2 (FR2) space - RF semiconductor technology yielding limited amplifier power levels, efficiency, linearity, and noise. Digital baseband issues in which the requisite sample rate has now far exceeded the state-of-the-art field-programmable gate array (FPGA) and even application-specific integrated circuit (ASIC) clock rates that we are running out of ideas about how to address baseband data rates of hundreds of Gbps. This is not to mention the challenges of mobile-system antenna technology for wavelengths that are below 2mm.

ManyNets

Global fragmented spectrum policy means radio systems of different technologies operating in varying-width slices of spectrum that vary from country to country. Between existing wireless communications systems and newly added bands and technologies, the available communication bandwidth is quite large. However, it is very difficult to tap in an efficient manner - during parts of the day, some bands lie completely fallow while others are at their capacity limit. The vision of ManyNets is for a seamless use of these systems that is flexible depending on location and demand. The challenges are that many of these systems were never designed to work in conjunction with each other.

Time-engineering

Very low latency combined with precise timing of message flow will be key to opening new use models. The concept of a high-latency situation, but one that has very precise and guaranteed timing is quite difficult in today’s networks. Today’s networks tend to operate in a stateless and “best effort” manner with overlay protocols, to give the impression of time-sensitive networking. The redesigns needed for true time-engineering impact not just 3GPP, but also Internet Engineering Task Force (IETF) and other bodies. I read a recent paper from European Telecommunications Standards Institute (ETSI) that stated the percentage of use of IPv6 in fixed networks is still in the single digits. This means that transitioning to new fundamental protocols in the IP and transport layers is glacial. Mobile benefits from 5G being designed from the ground up as an IPv6-only system. However, the true value of 6G will come from a better marriage between mobile and fixed networks.

AI-enabled networks

AI is enabling breakthroughs in medicine, quantum research, and even software tests. However, we have a way to go. The complexity of today’s networks and the data associated with operations is a great environment for AI to be applied, to optimise performance and efficiency, while increasing flexibility. The networks will be a more integral part of society and the network management equivalent of AI misidentifying a photograph or executing emergency automobile braking in an open motorway is something that our networks cannot afford.

Security

The headlines of the last few months should make it clear how critical network security is. Can somebody break it? Can they get in and get your data? Will you even know if they did? How quickly will your network recover? Even for 5G, the security situation is not mature, and much work is required. Given that the security threat surface for 5G is far beyond that of previous generations, one can expect that 6G will be even more so. Government and private entities have teams of smart innovative people developing malicious intrusion capability for networks and that level of innovation is constant. So, the challenges are to make the network secure at all levels, to know when someone is trying to breach it, and to recover quickly. From a Keysight perspective, we have capabilities in each of these areas and while we hardly have a full suite of 6G solutions in these spaces, we see opportunities to collaborate with industry leaders and develop solutions alongside these experts to make 6G real in every sense.

5G is struggling to arrive because of its infrastructure requirements, while 6G will build on 5G Infrastructure and enhance connectivity – on land, or even in space. When will that infrastructure be in place around the world?

Operators and vendors aren’t struggling to make 5G arrive. The rollout of this technology is consistent, if not faster than that of previous generations and it is paced by policy and economic factors because these investments are high and those making the investments have shareholders to please in the near-term. It is not too soon to begin the 6G conversation, these evolutions take time. The technical hurdles are significant, and many innovators must contribute to overcome these hurdles and develop systems that will work consistently around the world. People my age were in their 20s before the idea of carrying a radio in your pocket to communicate with someone in another country moved from science-fiction to reality. It may not seem that long, but the 10-20 years that it takes to work out a new generation means you start working before the previous generation is mature and sometimes before it is mainstream. There is speculation that 5G was the last ‘monolithic’ generational transition and that 6G may look more like an evolution. This is not true because of the dramatic changes in system behaviour. Like 5G, some of 6G will be an evolution, but some will be revolutionary and taken as a whole; we can expect a step-function in technical capability. 5G and 6G interest developed a good decade apart from each other. There are no R&D projects on 6G now – only research. The same was true when I started working on 5G in 2014, no development, just research.


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