The ITU Radiocommunication Sector (ITU-R) has recently published Recommendation ITU-R M.2150 titled ‘Detailed specifications of the radio interfaces of IMT-2020.’ The newly published Recommendation, formerly called ‘IMT-2020.specs,’ represents a set of three terrestrial radio interface specifications which have been combined into a single document.
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” (India/TSDSI). Those technologies are the basis for the implementation of 5G Radio Access Networks (RANs) 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/DECT Forum and Nufront, have been granted an exceptional review within the IMT-2020 process extension. Based on consideration of additional material, if they successfully complete the evaluation process they will be included in a subsequent revision Recommendation ITU-R M.2150.
It is important to note that the frequencies/spectrum arrangements to be used are not specified in M.2150. Instead they are contained in a yet to be completed revision of ITU-R M.1036: ‘Frequency arrangements for implementation of the terrestrial component of International Mobile Telecommunications (IMT) in the bands identified for IMT in the Radio Regulations.’
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 5G standalone (SA) mode that does not rely on LTE is being progressed by 3GPP which does not plan to liaise their documents to ITU-T. Indeed, it appears that all non-radio aspects of IMT 2020 will be specified by 3GPP and network operators in conjunction with their 5G Core network suppliers.
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.
ITU-R 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.