By Caio Castro
The International Telecommunication Union (ITU) plans to finish the initial 6G standardisation process “no later than the year 2030”, according to an official draft 6G framework. The ITU-R study group in charge of the document reached an agreement last week. It awaits adoption at the end of September.
“From March 2021 to June 2023, there were numerous adversities and challenges [in getting to the final version of the 6G vision],” the group chair, HyoungJin Choi said in a social media post. “As 6G Vision Chair, I am happy to be able to share this honour with all of you. Also, I am happy to have been able to breathe with you over the past two years,” he added.
According to the timeline recommended by the study group, 6G spectrum might be identified at the World Radiocommunication Conferences (WRC) 23 and WRC-27. The document points out that deployments could happen before 2030 in some countries, including trial systems. This may well be a nod to assertions from countries such as South Korea that they plan to deploy 6G systems in 2028.
Many of the topics addressed are no surprise, but it is significant to have them included in the ITU’s first official document outlining the next generation of mobile connectivity. Priorities and trends referred to include sustainability, inclusive connectivity, preserving privacy and security. However, the document has been authored by the ITU-R, so the bulk of the framework’s focus is on radio demands, use cases and KPIs.
Several countries and associations contributed over the past two years of discussions. They include IAFI (India’s body for ITU engagement), the High-Altitude Platform Station (HAPS) Alliance, the Wireless World Research Forum (WWRF), and others.
Important note: Because the group sits under the terrestrial services department, non-terrestrial networks are considered officially out of scope of their approved framework. However, the document acknowledges repeatedly that non-terrestrial networks will need to play a key role in 6G delivery.
Terahertz and Other Ranges for 6G
The document highlights several areas for research and development of 6G, but spectrum might be among the least surprising ones.
Among the recommendations, the study group concluded that we need to “consider spectrum in higher frequency ranges above 92 GHz as a complement to the use of lower frequency bands.” More specifically, bands around 100 GHz, 140-160 GHz, 220-240 GHz, and around 300 GHz could potentially be candidates for further investigation.
However, the group suggests looking at other lower frequencies too, all the way down below 1 GHz.
According to the document, different use cases and scenarios will call for different ranges. Low bands will continue to be deployed for nationwide coverage. Mid bands will “provide a balance between wide area coverage and capacity.” The millimetre wave spectrum is also considered a candidate for use in 6G.
6G Capabilities
The document outlines 15 metrics or capabilities which are “estimated targets for research and investigation of IMT-2030.” Some of these are expansions upon 5G and others will be new.
The document goes on to comment that “These values may further depend on certain parameters and assumptions including, but not limited to, frequency range, bandwidth, and deployment scenario. Further these values for the capabilities apply only to some of the usage scenarios and may not be reached simultaneously in a specific usage scenario.”
Peak data rate: 15-200 Gbit/s are possible examples, while other values might be considered.
User-experienced data rate: 300-500 Mbit/s, while faster speeds might be considered.
Spectrum efficiency: the average data throughput per unit of spectrum resource and per cell. The framework aims at an efficiency of 1.5 to 3 times greater than 5G.
Area traffic capacity: 30 Mbit/s/m2 and 50 Mbit/s/m2 are possible examples.
Connection density: The research target of connection density could be 106–108 devices/km2.
Mobility: The research target of mobility could be 500–1,000 km/h.
Latency: The research target of latency (over the air interface) could be 0.1 – 1 ms.
Reliability: The research target of reliability (over the air interface) could range from 1-10−5 to 1-10−7.
Coverage: No metric provided.
Positioning: The research target of positioning accuracy could be 1 – 10 cm.
Sensing-related capabilities: No metric provided.
AI-related capabilities: Functionalities include distributed data processing, distributed learning, AI computing, AI model execution, and AI model inference. No metric provided.
Security, privacy, and resilience: No metric provided.
Environmental sustainability: Energy efficiency (in bit/Joule) should be a quantifiable metric – but no numerical reference was provided.
Interoperability: No metric provided.
The following graphic, retrieved from the document, illustrates the 15 capabilities:
Use Cases
Unsurprisingly, the official ITU document highlights some common usage scenarios for 6G – which indicates that the industry’s and academia’s expectations align with what the international body envisions for the future.
Immersive Communication: Immersion is set to extend the enhanced Mobile Broadband (eMBB) of 5G and appear in technologies such as XR and holographic communications.
Hyper-Reliable and Low-Latency Communication: This scenario extends Ultra-Reliable and Low-Latency Communication (URLLC) capabilities. Examples include communications in an industrial environment for full automation, control, and operation.
Massive Communication: This usage scenario extends massive Machine Type Communication (mMTC) capabilities. To be employed in smart cities, transportation, logistics, health, energy, environmental monitoring, agriculture, and other fields.
Ubiquitous Connectivity: Intended to bridge the digital divide and provide access to the internet in places like rural and remote areas.
Integrated Artificial Intelligence and Communication: Assisted automated driving, autonomous collaboration between devices for medical assistance applications, offloading heavy computation operations across devices and networks, creation of and prediction with digital twins, and 6G-assisted cobots.
Integrated Sensing and Communication: Unlocking sensing capabilities for communications can enable assisted navigation, activity detection and movement tracking, environmental monitoring (rain and pollution detection), and provision of sensing data on surroundings for AI, XR, and digital twin applications.
Next Steps at ITU
The ITU 6G vision suggests further research in four key areas – but not necessarily limited to them: radio interface standards development; access network-related issues; traffic characteristics; and spectrum-related issues.
The document will now wait for adoption by the Study Group 5 (SG5) of ITU-R. The next meeting is scheduled for September 25-26.
