IMT 2020: Concept of Global Core Specification (GCS) and references

SOURCE: ITU-R Document 5D/TEMP/728-E; 11 July 2019


When completed, Recommendation ITU-R M.[IMT-2020.SPECS] will contain the detailed specifications of the radio interfaces of IMT-2020. The structure and philosophy adopted for M.[IMT-2020.SPECS] for IMT2020 is based on those used in Recommendations ITU-R M.1457 for IMT-2000 and ITU-R M.2012 for IMT-Advanced, which have been successfully utilized for two decades through numerous revisions of Recommendations ITU-R M.1457 and ITU-R M.2012.

A key concept is the continued use of the Global Core Specification (GCS) provided by the GCS Proponent and references to standards of Transposing Organization(s) authorized by the GCS Proponent whereby the detailed standardization is undertaken within the Transposing Organization that operates in concert with the RIT/SRIT Proponent and/or GCS Proponent entities.

The relationship between the GCSs for IMT-2020 radio interface technologies and the corresponding transposed standards is such that the GCSs are the framework for their corresponding detailed transposed specifications. Recommendation ITU-R M.[IMT-2020.SPECS] may also include references to specific related standards of the Transposing Organizations. There may be one or more entities that exist within a GCS Proponent for a given GCS.

It is also permissible to not have a separate GCS for a particular radio interface technology, in which case all the detailed specifications of that particular radio interface technology (the Directly Incorporated Specification) would be fully contained directly within the Recommendation ITU-R M.[IMT-2020.SPECS].

This understanding of whether a GCS would or would not be utilized in the context of a particular radio interface technology within Recommendation ITU-R M.[IMT-2020.SPECS] is necessary so that the proper structure and content of the Recommendation is chosen to properly reflect the technology specifications.

Consequently, the RIT/SRIT Proponent is requested to indicate at an early stage to the ITU-R its preliminary intention to submit a Global Core Specification, in advance of the required formal certifications, which will be used to form the basis of information in the Recommendation ITUR M.[IMT-2020.SPECS].

ITU-R (Working Party 5D) will review any GCS or DIS submission(s) and agree/approve or suggest changes in conjunction with the development and the ultimate approval by ITU-R of the final published version of Recommendation ITU-R M.[IMT-2020.SPECS] and the established schedules.

ITU-R (WP 5D and/or the Radiocommunication Bureau) will maintain liaison with the relevant External Organizations (RIT/SRIT Proponents, GCS Proponents, and Transposing Organizations) on the required deliverables and also the relevant schedules and administrative matters associated with the various stages of the development of the Recommendation ITUR M.[IMT-2020.SPECS] and its revisions over time.

Respecting the integrity of the GCSs and ensuring that the transposed standards are consistent with the GCS:

To assure users of Recommendation ITU-R M.[IMT-2020.SPECS] of the integrity of the GCS for a particular technology, and to ensure that the transposed standards are consistent with the common globally agreed vision of IMT-2020, completeness and traceability of the GCS and the transposed standards is a foremost obligation of the ITU-R.

As noted above, the IMT-2020 specifications could be developed around a “Global Core Specification” (GCS), which is related to externally developed materials incorporated by specific references for a specific technology. The submitted GCSs as accepted by WP 5D for inclusion in Recommendation ITU-R M.[IMT-2020.SPECS] will be placed on the relevant ITU website and indicated by hyperlinks in each relevant technology Section of Recommendation ITU-R M.[IMT2020.SPECS].
Thus the GCS provided by the GCS Proponent would form the nucleus of Recommendation ITUR M.[IMT-2020.SPECS]. For each radio interface technology in Recommendation ITU-R M.[IMT2020.SPECS] (whether presented as a single RIT or as one of the component RITs within an SRIT) there will be only one corresponding GCS. A GCS will have one or more GCS Proponents. Each component RIT within a SRIT may be separately addressed with regard to its GCS and the associated GCS Proponents.

Each GCS would correspond to separate sets of transposed standards/specifications from one or more individual standards development organizations or equivalent entities. For each separate set of transposed standards/specifications, there will be only one Transposing Organization.

The referenced standards of the authorized Transposing Organizations must be technically consistent with the corresponding GCS while allowing a limited amount of flexibility to accommodate, e.g. minimal regional differences. An example of a regional difference would be a regional adjustment for differing frequency bands. Adherence to this format and principle assures a common global standard for IMT-2020 as codified in Recommendation ITUR M.[IMT2020.SPECS] including the external materials incorporated by reference.

The receipt of information with regard to Recommendation ITUR M.[IMT-2020.SPECS] that is related to a business relationship of the ITU and the relevant external organizations complements and support activities such as the technical work under the purview of the relevant Study Group within the ITU. It must be noted that where this document addresses administrative matters it does not intend to usurp the Study Group or Working Party authority but merely seeks to provide additional critical information to the deliberations on Recommendation ITU-R M.[IMT-2020.SPECS] as to the individual or collective intent and/or actions of the RIT/SRIT Proponents, GCS Proponents, and/or Transposing Organizations that support a particular technology, a corresponding GCS, and the related transposed standards.

A Transposing Organization is an individual entity authorized by a GCS Proponent to transpose the relevant GCS into specific standards and to provide specific references and hyperlinks (Transposition References) for the purposes of Recommendation ITU-R M.[IMT-2020.SPECS].  A Transposing Organization:

1) must have been authorized by the relevant GCS Proponent to produce transposed standards for a particular technology, and
2) must have the relevant legal usage rights.

It is noted that the entity or entities that make up a GCS Proponent may also be a Transposing Organization. It should also be noted that the term Transposing Organization is always indicated to be a single entity. It is also noted that, for the purposes of Recommendation ITU-R M.[IMT-2020.SPECS], the ITUR will only recognize as valid those Transposing Organizations that have been identified to the ITU-R by the GCS Proponent as authorized to transpose the GCS Proponent’s GCS.

Neither a GCS Proponent nor a Transposing Organization need to be a formal “Standards Development Organization” or “SDO.” For example, “SDO” here could represent an industry entity, organization, individual company, etc. that, if applicable, also qualifies appropriately under the auspices of Resolution ITU-R 9.


It should be noted that when a GCS is provided by the GCS Proponent it communicates the intention that at least one set of transposed standards/specifications would be provided to the ITU-R by a Transposing Organization by the required deadline in order for a particular radio interface technology to be fully complete within the Recommendation ITU-R M.[IMT-2020.SPECS]. It is recognized that a single entity may act as both the GCS Proponent and the Transposing Organization and could provide the GCS itself as the set of transposed standards or specifications.

ITU-R Working Party 5D will always, under the process of creating or revising Recommendation ITUR M.[IMT-2020.SPECS], perform a final quality and consistency check of the draft new or revised Recommendation in its final published form (which includes all references) as part of reaching final agreement to forward the finalized draft new or revised Recommendation to the appropriate Study Group 5 meeting for action.

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