Multiple Hurdles In The Race To 6G

The rollout of 6G will open the door to significant changes and possibilities, but whether this technology lives up to the hype will require massive collaborative efforts, huge investments in infrastructure, and solving some problems for which there are no precedents.

Multiple companies are already working on 6G technology, aiming for a maximum download speed of one terabit per second (Tb/s) with latency less than 0.1 ms — a 100-fold increase over 5G. If it works as planned, 6G would completely transform our daily lives and many vertical industries, including agriculture, smart transportation, entertainment, healthcare, industrial segments, public safety and smart cities. It also would empower the development of AI, VR/AR, voice, and connections for big data.

“The new capabilities of 6G networks will unlock new applications in robotics, health care, and industrial applications,” said Steve Hanna, distinguished engineer at Infineon Technologies. “But with these new applications come new, higher risks. A successful attack may cause not just inconvenience, but safety risks. With real-time applications such as robotics, just delaying the arrival of a message like ‘STOP’ could be catastrophic. To meet these challenges, 6G suppliers need to boost their security capabilities with cyber-resiliency, trusted computing, and post-quantum cryptography solutions.”

Still, the road to 6G is more challenging than most companies want to admit. The big question is whether those hurdles can be overcome before 2030, when its rollout is scheduled to begin in earnest.

Vision and benefits
If 6G works as planned, it will provide benefits across a number of vertical market segments. In a smart transportation setting, for example, 6G-enabled autonomous vehicles would provide convenience and other benefits. V2X/smart infrastructure connections could help eliminate avoidable collisions and increase driving efficiency with optimal city traffic management. 6G smart city support, meanwhile, would help ambulances overcome traffic holdups and more, cutting time off trips to the closest hospital. Ultimately, traffic accidents and collisions could be reduced to almost zero.

However, realizing greater efficiency, convenience, and other advantages with smart transportation comes with some must-haves, including comprehensive integration of fully connected autonomous vehicles, real-time connection to the cloud, real-time advanced mapping systems, fully functional V2X/cellular-V2X (C-V2X), and smart city/smart infrastructure. Many believe the key building block to make all of this possible is 6G, which enables speed and low latency to ensure real-time connection with no downtime. Autonomous driving needs more than ADAS and AI, it needs superfast cloud connections.

Fig. 1: The cloud-based automotive services include increased safety, better in-car experiences, HD mapping, and other remote services. Source: NXP and ABI research.

As connected health care moves forward, it too will look to the arrival of 6G connections for remote robotic surgeries in which connections must be fast and disruption-free. Reliability is mandatory. Even a lapse of a few seconds in internet availability could be disastrous for a remote surgical procedure.

Here, the whole infrastructure and supply chain – from high-speed 6G chips to reliable network equipment – needs to work together flawlessly. Successful deployment will let patients from any part of the world, including underdeveloped, remote areas, access the best health and technology care.

Potentially, high-speed connections can support full integration of vital signs monitoring, AI, augmented reality, and robotics – including exoskeletons – allowing medical professionals to cooperate globally. In addition, knowledge and technology can be shared to achieve better outcomes for patients.

“6G will have better performance and faster data rates than 5G, which will inevitably enable new applications,” said Sarah LaSelva, director of 6G marketing at Keysight Technologies. “However, to pick one at this stage of development that will be the killer app for 6G is difficult. The goals of 6G are big. They are designed to be wide-reaching, impacting more vertical industries and applications, and making a difference in the overall quality of human life.”

It may be that the biggest impacts of 6G will be related to optimization.

“With AI technology advances and the promise of AI native networks, 6G aims to optimize everything it touches in ways that are still hard to grasp,” LaSelva said. “6G will connect the human world, digital world, and physical world by adding wireless connectivity to more things – from IoT sensors to wearables to the machines in our factories. This creates more data that can be fed into AI algorithms, optimizing not only how our wireless systems run, but also everything connected to them.”

In 2022, Samsung demonstrated 6G speeds reaching 12 Gbps at a 30 meter distance indoors, and 2.3 Gbps at a 120 meter distance outdoors. Separately, Ericsson has been working on new spectrum technology, including the centimeter wave (cmWave), which supports the 7 to 15 GHz frequencies. Many organizations and universities are also doing research in 6G worldwide.

If it works as planned, this could be a boon to the entire communications industry. Market research firm Fact.MR projects 6G revenue will reach $300 billion by 2033. But whether it achieves that potential will depend on a number of factors, ranging from user experience and adoption to infrastructure buildout.

6G updates
A comparison of 5G and 6G in figure 2 below shows 6G is pushing the technology envelope in multiple ways. Besides speed and latency improvements, 6G also will bring about improved bandwidth, efficiency, reliability, and network coverage, significantly enhancing users’ experience.

Fig. 2: Comparison of 5G and 6G attributes. Source: “6G V2X Technologies and Orchestrated Sensing for Autonomous Driving,” https://arxiv.org/abs/2106.16146

Standards and consortia
As of today, there are no universally established standards for 6G. However, there are multiple 6G consortia being formed around the world.

The Alliance for Telecommunications Industry Solutions (ATIS), in cooperation with 3GPP, which defines the 5G standard, is attempting to define 6G. Its members include many tech heavyweights, such as AT&T, Cisco, Dell, Ericsson, Google, Hewlett-Packard, Huawei, Keysight, LG, Nokia, NTT Docomo, QUALCOMM, Samsung, T-Mobile, Verizon, and more.

Additionally, ATIS Next G Alliance in North America has collaboration agreements with 6G-IA (Europe), 5G Forum (Korea) and the Beyond 5G Promotion Consortium (Japan).

“In North America, ATIS’ Next G Alliance has been working with its 100+ members to accelerate North American leadership for 6G over the next decade through developing a North American 6G vision and roadmap with the goal of establishing a strong 6G marketplace,” said Mike Nawrocki, managing director of ATIS’ Next G Alliance. “These pre-standardization and pre-commercialization initiatives should strengthen the future direction of 6G standards development, which will commence as early as next year and deliver the first release of 6G standards by 2030. South Korea has announced its K-Network 2030 plan, which includes the launch of its commercial service of 6G network by 2028. Other regions have launched 6G research initiatives to help advance 6G to the commercial marketplace. The Next G Alliance in North America is in active discussions with U.S. government on advancing cooperation on 6G R&D.”

India’s Department of Telecommunications (DoT) established the Bharat 6G Alliance (B6GA) to support cooperation among public and private companies, academia, research institutions, and standards organizations. The Alliance submitted input on the 6G technology framework to the United Nations International Telecommunication Union (ITU) during the ITU Geneva meeting in June 2023.

Other regional research groups and organizations are off to an early start with the goal of establishing 6G guidelines and standards, as well, including 6Genesis’s project in Oulu, Northern Finland.

Looking beyond 2030 is United Nation’s International Telecommunication Union (ITU) Radiocommunication Sector, or ITU-R, with its ITU-R IMT-2030. In its initial draft recommendations for the framework, six usage scenarios were listed. They were immersive communication, massive communication, and hyper reliable and low-latency communication. Three new ones have been added, including ubiquitous connectivity, integrated AI and communication, integrated sensing and communication.

Ultimately, the various players in the supply chain — 6G chip developers, equipment and infrastructure providers, software developers, and hardware manufacturers — will need to work together to avoid 6G fragmentation. In the meantime, companies are working independently or cooperatively, striving to establish themselves as front runners.

6G hurdles
Getting to successful 6G implementation will not be smooth sailing, and there are many hurdles to be overcome. The obvious hurdle will be building the network and mobile 6G infrastructure. Even though 6G can build on 5G, the migration from 4G to 5G is taking a long time ,and is still evolving. Building the infrastructure 6G is sure to be very costly. Also, many network issues including spectrum allocation and usage need to be resolved.

Terahertz waves
Achieving terahertz waves which have the characteristics of both sustainable throughput and flexibility will be challenging, and it will take time for the entire 6G supply chain to mature.

“Besides the fundamental technical challenges for 5G, 5G+, and 6G mmWave applications with signals prone to interference from weather or anything solid – think windows and walls – the industry still lacks a killer app requiring 6G capabilities,” said Frank Schirrmeister, vice president of solutions and business development at Arteris. “Also, the intelligent transport of the massive amount of data at two orders of magnitude higher data speeds will be challenging on and between chips and chiplets. And, of course, architecturally defining the best balance of computing from devices through edges to data centers will be critical. In addition, consumer concerns around safety, security, and privacy will impact technology acceptance and, with that, technology adoption.”

Fig. 3: 6G timeline. Source: Ericsson

6G test
6G testing is another important area that cannot be overlooked. Additionally, successful implementation of 6G in one location does not mean it can scale, which helps to explain why some countries have faster 5G speeds than the United States, which has much larger territories to cover. With 6G, the expectation of reliable “24/7” network services without disruption may take a great deal of time and effort to achieve.

Keysight’s LaSelva noted that achieving high data throughput performance of 100 Gbps or higher for 6G sub-THz (100 to 300 GHz) frequency bands could involve utilizing high-order modulation with wide or even extreme occupied bandwidths of 10 to 30 GHz. “Supporting wide modulation bandwidths requires very fast analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) with high dynamic range and linearity to address high peak-to-average candidate 6G waveforms. IF/RF/THz radio hardware and channel impairments will introduce significant amplitude and phase impairments over wide modulation bandwidths, which could be addressed with receiver baseband equalization algorithms. However, this approach will require high clock rates with a high degree of implementation parallelization, which can quickly consume baseband resources.”

Measuring the error vector magnitude (EVM) performance of these wide-bandwidth high-speed systems will demand high-performance test systems with extremely high-speed arbitrary waveform generators (AWGs) and digital oscilloscopes to generate and analyze wide bandwidth waveforms with low residual EVM performance, she said. “For example, Keysight’s M8199A AWG touts sample rates up to 128 GSa/s and analog bandwidths of 70 GHz across four channels, and the company’s UXR digital oscilloscope has sample rates up to 256 GSa/s and analog bandwidths of 110 GHz across four channels. These instruments create the foundation of a sub-THz testbed for 6G research, enabling engineering teams to evaluate and measure their high-speed 6G technologies.”

Security
With higher speed and more connections enabled, the level of cyber risk will also increase.

In the Next G Alliance report, “Trust, Security, and Resilience for 6G Systems,” ATIS said the organization of a trustworthy network is a lifecycle that includes a strong assurance of security, privacy, reliability, availability, and functional safety. The network deployment process should go through standardization, design, development, and integration phases.

Fig. 4: The organization of a trustworthy network is a lifecycle that includes a strong assurance of security, privacy, reliability, availability, and functional safety. Source: Next G Alliance’s “Roadmap to 6G.”

Impact on chips
The performance requirements of 6G development will have a major impact on future chips and IP. Some of the hurdles include a mixture of chips, IP, chiplets, and power management.

“Coverage, cost, and power are the significant drivers for transitioning from 5G to 5G+ and, eventually, 6G,” Schirrmeister said. “Driven by the chosen spectrum and technologies like beamforming, building penetration significantly hinders 5G coverage and indoor usage. Most of the chips will be chiplet-based, as a mix and match of different technology nodes will likely be the best approach. This strategy could enable a higher spectrum and the ever-rising cost of the equipment powering cellular networks, while carefully managing power.”

From a network-on-chip (NoC) perspective, massive data volumes, data locality, and computing requirements will drive protocol and bandwidth requirements.

“On top of that, properly combining NoCs across chiplets and related coherency aspects will determine requirements for the NoC characteristics, memory, and die-to-die controllers, and PHYs. Chiplets will be essential for 6G applications, as they will allow developers to combine the most appropriate technology nodes for the individual parts of the designs. Think advanced 3nm, 2nm, and beyond technology nodes for HPC-type computing of data, combined with the most appropriate technology nodes for RF aspects,” he said.

In short, 6G will have multiple fronts to conquer, including achieving the speed envisioned. Using 5G as an example, we are seeing a peak download speed of 3.3 Gbps in North America. Average speed is much lower and far from the targeted 10 Gbps in the 5G specification. Achieving 1 Tbps will be much more challenging and most likely take longer.

Looking ahead, data management is another area that needs more R&D, since more data will be generated with higher speed. That, in turn, will directly impact data storage requirements, cybersecurity, traffic management, and analysis. If this is not done correctly, time, effort, and cost will go up, along with inefficiencies in 6G networks.

Conclusion
The momentum behind 6G is strong. While the technology provides many benefits, the hurdles of successful deployment cannot be ignored. Some of these hurdles include achieving terahertz waves, 6G infrastructure, development of 6G chips, testing, and cybersecurity. Additionally, the alignment of 6G supply chain, scalability and the massive data management can be challenging.

6G availability by 2030 is an ambitious goal. Getting there may be tricky. At this point it’s not clear whether 6G will end up being ubiquitous networks available to all, or whether it will be a collection of regional networks with various speeds and modified specifications.

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