This is the second part of a conversation between 6GWorld™ and Keysight’s 6G project lead Roger Nichols. As a specialist test and measurement company, Keysight works with the advanced radio labs in academia, vendors and operators globally. You can read the first instalment of the conversation here.   

5G rollout and 6G interest developed at about the same time. Just as 5G rolls out commercially, 6G R&D projects have launched. Where will 5G end and 6G begin?

Operators and vendors are not 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 behavior described above.  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.

Two additional items I need to clarify:  5G and 6G interest developed a good decade apart from each other.  There are no R&D projects on 6G now – only research. Same was true when I started working on 5G in 2014, no development, just research. 

Where will we see the launch of 6G service first; and when?

6G commercialization is seven to ten years in the future. It’s impossible to predict the “first country” to launch at this point.  The concept of an “international race” to be first to commercialize 6G is as difficult as it was in 5G.  Competition in the global wireless world is between commercial entities, not between governments, and we will continue to be driven by those forces. Just like with 5G, we operate amid the three forces of technology, policy and business model.  The policy side will have an impact on who deploys the first commercial networks, but it will not be the sole driver.  Today the investment in 6G research is global.  It is happening in every continent (maybe not Antarctica) and in every country with advanced applied research entities.  The countries with major wireless investments and those that host the headquarters of the largest wireless businesses are all quite visible: China, Korea, Japan, the USA, most of Western Europe, India, Taiwan—all present and doing research.

You mentioned Taiwan – what are the business opportunities for Taiwanese companies in the 6G era?

Taiwan has a couple of unique positions. First, they are home to the three largest computer manufacturing companies in the world. These companies also happen to be large manufacturers of wireless equipment.  So, Taiwan has companies that understand technology, global supply chain management and logistics in the electronics industry.  Taiwan also has an excellent infrastructure, a strong university system, and the Industrial Technology Research Institute (ITRI) government research lab is home to some amazing technological work.  The society is innovative and will remain that way.  As always, Taiwan will be strong player in mobile wireless.

What do you see as the biggest technology challenges as we move towards a 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 optimized networks, and
• Next Generation security. 

There are enormous challenges in each of these areas.  The following are a few examples:

In Next Generation 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.

Then there are 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 is a tough challenge. 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 is enabling breakthroughs in medicine, quantum research, and even software test.  However, we have a way to go in AI-enabled networks. The complexity of today’s networks and the data associated with operations is a great environment for AI to be applied, to optimize 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.

And not least, 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.

What do design and development engineers need to know about embedding 6G in their designs?

Right now in 6G, all the work is research-based; researchers, physicists, engineers, and scientists are exploring the issues related to the challenges I have outlined and others.  The key priorities for these technical innovators are to build a clear understanding of the existing system, identify drawbacks and potential, and work on the fundamental issues with the underlying technologies, sub-systems, and overall architectures that need to be addressed to realize the vision. 

Perhaps the most important consideration is that mobile wireless technology covers all electrical engineering disciplines, plus many non-EE disciplines.  Engineers and researchers must be multi-disciplinary to understand digital systems, data communications, software, signal processing, networking, power management, RF design, antennas, electromagnetic propagation theory, semiconductor technology, and electromagnetic physics of materials.  If you think you don’t have to understand other technologies, discuss it with someone who builds masts and mounts for radio antennas and needs to consider mass, wind-loading and complexities of installation and maintenance. Think holistically.