The ITU Radiocommunication Sector (ITU-R) has recently published Recommendation ITU-R M.2150 titled 'Detailed specifications of the radio interfaces of IMT-2020'.
Following the evaluation of various radio technology candidates for IMT-2020 at the end of last year, the newly published Recommendation represents a set of terrestrial radio interface specifications which have been combined into a single document.
The development and approval of this international mobile technology (IMT) standard will support several use cases that leverage the advantages of 5G.
For instance, it will contribute, amongst many other things, to accelerating the response time of autonomous vehicles and enable new and more realistic augmented/virtual reality (AR/VR) experiences.
Understanding the IMT process
A solid grasp of the IMT process is key to understand the significance of the latest 5G developments at ITU. The process consists of 4 main phases:
1. "ITU-R Vision" and definitions
2. Minimum requirements and evaluation criteria
3. Invitation for proposals, evaluation, and consensus building
4. Specification, approval, and implementation
Note: The results of these procedural steps are documented in ITU-R Recommendations and ITU-R Reports.
The "ITU-R Vision" set out at the beginning of each IMT process defines what is needed to be accomplished. After that, candidates who want to support that vision may start developing functional technology that meets those requirements.
Once the standardization bodies have submitted IMT candidate technologies, the evaluation process begins. This is done in a collaborative process between ITU Member States, equipment manufacturers, network operators, standards development organizations (SDOs) and the academic community.
This unique global framework serves as a forum for discussion and agreement on the capabilities of new radio technologies.
One of the key features of the IMT process is its ability to ensure the various radio interface technology candidates are handled in a neutral way.
Once the radio interface has been finalized and consensus has been reached, the process concludes with approval and implementation.
What's in the latest Recommendation?
The current version of this Recommendation on IMT-2020 specifications (Recommendation ITU-R M.2150) contains 3 radio interface technologies: "3GPP 5G-SRIT"; "3GPP 5G-RIT" and "5Gi". Those technologies are the basis for the implementation 5G networks around the world. After a period of 7-8 years of hard work across the industry, the evaluation of these 3 IMT-2020 technologies has culminated in an approval from ITU's 193 Member States.
Two more radio interface proposals, submitted by ETSI (TC DECT) Forum and Nufront, have been granted an exceptional review within the IMT-2020 process extension. If, based on consideration of additional material, they successfully complete the evaluation process they will be included in a subsequent revision Recommendation ITU-R M.2150.
5G: An economically viable evolution
When a specific radio interface technology (RIT), or a set of radio interface technologies (SRIT), is approved it will be considered to be part of the IMT family (IMT-2000, IMT-Advanced, IMT-2020) of radio interfaces for which there are frequency bands identified within the ITU Radio Regulations.
Just as we learned in the journey of mobile from 3G to 4G, the transition from one generation to another will be incremental, with early deployments starting at 5G radio and leveraging existing 4G network infrastructure.
In fact, the 4G evolved packet core (EPC) will coexist with the 5G core for quite a while, enabling operators and enterprise customers to take advantage of 5G features such as network slicing and user plane flexibility.
5G NR (New Radio) wireless mobile communications will bring higher data rates, reduced latency, and greater system capacity. The first implementation of 5G NR uses existing 4G LTE infrastructure in a non-standalone (NSA) mode. A full standalone (SA) mode that does not rely on LTE will follow later.
To facilitate the smooth evolution from 4G LTE to 5G NR, the 5G NR standard offers the possibility of adapting to existing LTE deployments and sharing the spectrum used exclusively by LTE today. The enabling mechanism, known as "dynamic spectrum sharing" (DSS), allows 5G NR and 4G LTE to coexist while using the same spectrum and as such allowing network operators a smooth transition from LTE to 5G NR - presenting one option for an economically viable evolution.
Towards 2030 and beyond
When it comes to future developments beyond IMT-2020, the work has just started. In 2021, it is expected that ITU-R will define the schedule for future revisions of the Recommendation ITU-R M.2150, to accommodate future improvements to the standards, as well as the possibility of introducing new IMT-2020 radio interfaces. Looking even further ahead, ITU-R Working Party 5D has already started to examine future technology trends for "IMT towards 2030 and beyond".
This work could include anticipating new use cases for IMT and subsequently the identification of any gaps, as well as new technical enablers necessary in the 2030 timeframe.
Once again, the tried-and-tested IMT process will be applied, starting with a clear vision and definition phase. After the ITU-R Vision towards 2030 and beyond states what is needed with the next 10 years in mind, many standardization bodies (e.g. 3GPP etc.) will then define and develop fitting functional technologies for the next generation of IMT.
Working Party 5D has invited organizations within and external to the ITU Radiocommunication Sector (ITU-R) to provide inputs for its June and October meetings in 2021, which will help the development of the forthcoming report "Future Technology Trends towards 2030 and beyond." A first draft of this new report contains a list of driving factors in the design of IMT technology, as well as a list of possible technologies to enhance the performance and precision of both the radio interface and radio network.
The report is very likely to also include technologies for native artificial intelligence (AI)-based communication.
ITU relies on its membership – both Member States and sector members – as well as on external organizations from standardization bodies to academia to research institutes, to contribute to this important work.
This successful cooperation has been practiced for decades and ITU now looks forward to continuing this shared journey so that all may benefit from a globally valid standard.
Joining ITU means actively participating in this exciting challenge of driving innovation in the telecommunications sector within and beyond 5G.
Learn more about IMT-2020 on the relevant website and the accompanying FAQ. If you have particular technical or IMT-process related questions, you can also approach the ITU-R SG 5 Counsellor.
