Executive Summary, SG15, October 2025

​Geneva, 13-24 october 2025
ITU-T Study Group 15
Networks, Technologies and Infrastructures for Transport, Access and Home
Study Group 15 Chair: Glenn Parsons

Study Group 15 held its second meeting of the 2025-2028 study period in-person in Geneva from 13 to 24 October 2025, had more than 400 registrations and was attended by 375 delegates representing 44 countries.​

The meeting received 369 contributions and 409 TDs.  The meeting observed the 12-day contribution deadline of Recommendation ITU-T A.1, and almost all of the contributions to this meeting were submitted using Direct Document Posting (DDP).

SG15 approved three new Recommendations, consented  45 texts (7 new and 21 revised Recommendations, 15 Amendments, and 2 Corrigenda), and agreed 10 supplements.   

Interim activities prior to the next SG15 plenary have been planned as virtual or in-person, consisting of 34 single-day or multiple-day meetings.

In fulfilling its lead study group responsibilities, SG15 revised the Access Network Transport (ANT) standards overview and work plan, the Home Network Transport (HNT) Standards Overview and Work Plan, and the Optical Transport Networks and Technologies (OTNT) standardization work plan.

SG15 generated 42 Liaison Statements. These included an update to the JCA IMT-2020 concerning the IMT-2020 roadmap, and a request to ITU-R regarding existing and proposed work on free space optics. 

WP1/15 – Transport aspects of access, home and smart grid networks

WP1/15 Chair: Ian Horsley, Vice Chair: Frank Van der Putten

WP1/15 approved 3 Recommendations, consented 7 Recommendations, agreed 6 Supplements and initiated 6 new work items. 

Q2/15 met at the ITU-T in Geneva on October 16-17. Approximately 50 people attended reviewing about 50 contributions and 20 temporary documents. 5 documents were consented including amendments to the GPON TC layer (G.984.3), the WDMPON PMD and TC layers (G.9802.2), High Speed PON common TC layer (G.9804.2), High Speed PON PDM layer (G.9804.3) and PON coexistence (G.9805) recommendations.

3 supplements were agreed, including G.suppl.55 on Radio-over-fibre technologies and their applications, G.suppl.88 on PON technologies above 50Gb/s per wavelength and a revision to G.suppl.81 on the practical aspects of PON security.

The group also made progress on updates to OMCI (G.988) and a new supplement on Low latency Services.

The group participated in 3 joint meetings with Q6 and Q12 (regarding the “ION 2030" work), Q5 and 6 (concerning hollow core fibre), and Q3 (regarding several topics of joint interest).

The work program was updated, with 4 new or revised work items, including new joint work with Q3 on  management and control interfaces of fibre in premises networks, use cases and requirements of AI enhanced ION-2030 for broadband and network characteristics and use cases for the 10Gbps broadband era. The group also produced 2 outgoing liaison statements and agreed four interim meetings up to the next plenary. 

Q3/15 met for 4 days (20 – 23 October 2025) in Geneva, Switzerland, addressed 39 contributions, reviewed 2 incoming liaison statements and prepared 1 outgoing liaison.

3 draft Recommendation on network management of High speed fibre-based in-premises transceivers (G.9943), WLAN management control interface (WMCI) for in-premises network (G.9949) and Technical requirements of extended reality service over in-premises networks (G.9975) were approved after resolving the last call comments. Amendments to Point-to-point fibre in the premises (G.9930) and WLAN management control interface (WMCI) for in-premises network G.9949) were consented.

Supplements on Use cases and Requirements of Fibre-in-premises for Small & Medium Enterprise applications (G.suppl.91, Coexistence between G.fin and G.Xfin systems G.suppl.90 and Coordinated management of access and fibre in premises networks  (G.suppl.89) were agreed.

The work also progressed on G.fin, G.p2pf, G.Edge4Home and G.Sup.TwinHome.

New work was started on a supplement Beyond 10Gbps fibre in-premises network: use cases, system requirements & technology options in addition to the joint new work mentioned in the Q2 section.

A joint session with Question 2 in WP1/15 was also held on Tuesday afternoon to discuss the joint projects.​ 

Q4/15 met for half a day in Geneva. One liaison was received and reviewed with no action. The work programme was reviewed and confirmed. Contributions are invited for the next meeting to progress the work. 

A joint session of Q2, 5, and 6 to addressed hollow core fibre. A joint session of Q2, Q6, and Q12 discussed ION-2030 issues. A joint session of Q2 and Q3 was also held. 

WP2/15 – Optical technologies and physical infrastructures

WP2 Chair: Paul Doolan; WP2 Vice-Chair: Sudipta Bhaumik

All the Questions of WP2 met during the plenary; we note with interest that around 10 new delegates joined our meeting with their interests spread across all our Questions.

The Questions of WP2/15 obtained consent for 13 Recommendations and 1 corrigendum, agreed 1 supplement and initiated 15 new work items, in addition WP2 prepared 12 outgoing liaisons. 

Q5/15 finalized the Revisions of Recommendations L.102 (aerial cable), L.105 (drop cable), L.107 (sewer duct cable), and L.110 (direct surface cable).  It was also agreed to establish two Recommendations for a weakly coupled multi-core fibre with backward compatibility to G.652/G.657 and G.654 fibres to support submarine, terrestrial, and datacentre networks and one Recommendation on installation of ADSS cable along electrical power line.  Finally, Q5 agreed to introduce the coating property specifications into the existing G.65x Recommendations.

Four Interim E-meetings and correspondence activities are planned to progress revision works on multiple Recommendations, on new Recommendation on weakly coupled multicore fibers and its test methods and potential technical report on hollow core fibers.

Q6/15 consented G.681 (ex. G.dfos) a new Recommendation on joint sensing and communication in optical networks. This is the first standard in the industry for this technology and application.  Q6 also consented G.641 (ex. G.fso) a new Recommendation on free space optics for backhaul applications. G.641 was sent for consent after coordination with ITU-R.

It was agreed to start new technical report TR.ION-aiDC on 'Optical technologies for datacenter interconnects and networking in ION-2030', to intercept the evolution occurring in datacentres as a consequence of the introduction of AI at mass scale.

Finally, two joint correspondence activities were agreed:

• With Q2 and Q5 to investigate Hollow Core Fibers technologies and applications to figure out potential standardization paths
• With Q14 on 'smart' optical pluggable modules, i.e., modules having an additional low-rate channel for control and management information.

A RGM hosted by Telefon AB - LM Ericsson and the Institute of Communication, Information and Perception Technologies - Scuola Superiore Sant'Anna, will be held in Pisa (Italy) from 9th to 12th February 2026.

Q7/15 consented a new Recommendation L.405 (ex L.pcc – pre-connectorised cabling components) and for a Revision to L.391 (outside plant).  In addition, it was agreed to start work on revisions of L.250 (access topologies) and L.302 (outside plant maintenance). A draft revision L.361 (ex L.64 - ID tags) was prepared with the objective to consent it at the next plenary.

Q8/15 consented a corrigendum of G.971 (general features), a revision of G.976 (test methods) and a revision of G.979 (monitoring) for optical submarine cables. Q8 also agreed to start a new Recommendation ITU-T G.9730 "General features of optical fibre submarine cable systems with sensing capabilities". 

WP3/15 – Transport network characteristics

WP3 Chair: Tom Huber; WP3 Vice-Chair: Silvana Rodrigues

WP3/15 consented 24 Recommendations, agreed 3 Supplements, and initiated 25 new work items. 

WP3 chair summary

• Technical papers providing overviews of MTN and OTN, and a technical report on ION-2030, were agreed. These all include content from multiple Questions.
• Q10/15 has initiated the approval process on revised Recommendation G.8020.3 “Ethernet" and made progress on a revision to Ethernet service definitions in G.8011.
• Q11 has made significant progress on the definition of Beyond 1 Tb/s OTN, including module-framer interfaces, and has initiated the approval process for a revision to G.798 that splits the content into multiple documents. Q11 has also continued to discuss MTN enhancements and topics related to network protection.
• Q12/15 has initiated work on amendments to the OTN and media architecture Recommendations, and led cross-Question efforts to complete work on technical papers providing overviews of MTN and OTN as well as a technical report on International Optical Networks towards 2030 and Beyond (ION-2030).
• Q12/15 updated the OTNT Standardization Work Plan.
• Q13/15 continued its work to enhance the accuracy and robustness of time and frequency distribution.
• Q13/15 is continuing work on extending the ITU defined synchronization frameworks and profiles to apply to synchronization in data centres. This work is being undertaken in cooperation with IEEE P1588, IEEE P1952, IEEE P3335, IEEE IC Timing in Datacentre and OCP.
• Q14/15 is continuing to extend the suite of management Recommendations to allow management of the new functions recently defined by Q10, Q11 and Q13. A technical report on optical physical infrastructure resources management for transport networks has been initiated.  
• Q14/15 is continuing to work in cooperation with IEEE 802.1, IEEE 1588, IEEE 802.3, Linux Foundation ONMI, MEF, BBF, and IETF to provide consistent information models and YANG data models for transport networks; the current focus of this work is on the management of network synchronization and Ethernet.
• Q14/15 is continuing to enhance SG15 guidelines on making SG15 YANG modules available on the IETF's YANG repository and the draft guidelines for ITU-T Q14/15 draft Recommendations with UML and YANG models. 

Per Question highlights:

Q10/15 consented revised ITU-T G.8020.3 “Ethernet" edition 2.0 that incorporates by reference IEEE Std 802.3-2022 as amended and, new to this edition 2.0, also incorporates by reference IEEE Std 802.3-2022/Cor 1-2024. Q10/15 prepared toward consent in July 2026 draft revised G.8011 “Ethernet services characteristics" to cover the latest carrier Ethernet-centric standards (MEF 23.2.2, MEF 47.1, MEF 151) of Mplify (former MEF). Contributions on G.8032 “Ethernet ring protection switching" were discussed to clarify its operation without requiring the Recommendation to be amended or revised. Q10/15 proposed a new work item agreed at this meeting toward consent in July 2026 for a revision of ITU-T G.8020.3 edition 2.0 to continue aligning with the evolution of IEEE Std 802.3.

Q11/15 made significant progress on all of its agenda topics, with six consented Recommendations, three agreed information documents and approval of two new formal work items.  Q11 continued its focus on work associated with OTN for rates beyond 1 Tbit/s (B1T).  Other work topics are related to fine grain MTN (fgMTN) and fine grain OTN (fgOTN). 

The consented Recommendations include the following: G.798, G.798.2, G.798.3 and G.798.4, which are the overview, media, OTU and ODU, and FlexO portions, respectively of former G.798 “Characteristics of optical transport network hierarchy equipment functional blocks".  In addition to the consented items, Q11 items for agreement included the G.798 implementors' guide, which provides a spreadsheet to map between clauses of the previously published G.798 and its new constituent pieces as an aid to G.798 users. An amendment to G.8312.20 providing an overview of fine grain MTN was also consented.  Two technical papers were also agreed, providing introductions to the networks, applications and technology associated with OTN and MTN. 

The B1T discussions resulted in significant progress on common understandings and further narrowing and clarification of the key remaining open questions, each of which was captured as a study point for the associated G.709.1 (common elements), G.709.5 (short reach interfaces), or G.709.6 (B400G long reach interfaces) Recommendations.  These results will enable further significant progress at the upcoming Q11/15 interim meetings and correspondence activity. 

An initial draft of Recommendation G.709.mfi was reviewed, in preparation for it to be consented at the next SG15 meeting.  It will provide normative reference for module-to-framer (MFI) FlexO interfaces with lane rates ≥100 Gbit/s, while informative references for lower rates remain in G.Sup58 where they are currently defined. 

A new work item was also added for a G.8312 revision.  In addition, Q11/15 considered protection switching applications associated with fine grain networks. 

Q11/15 plans to hold a face-to-face interim meeting in March 2026 in Geneva, with separate virtual meetings associated with MTN in January 2026 and B1T in February 2026.

Q12/15 coordinated work on the technical paper International Optical Networks towards 2030 and Beyond (ION-2030). Input was received from Questions across all Working Parties in SG15. A joint meeting with Q2/2 & Q6/15 was held on this subject. GSTR.ION-2030 was agreed and liaised to multiple SDOs for feedback. ION-2030 is a strategic framework developed to guide the evolution of International Optical Networks.

An Amendment to G.807 was initiated to study media impacts of free space optics and distributed fibre sensing work in Q6/15 and Q2/15. An Amendment to G.872 was initiated to capture OTN architecture work underway in Q11/15 on the module-framer interface and B1T topics.

An Amendment to G.7702 was initiated to study how the CPI might be instantiated from work in other SDOs. The Technical paper on Enhanced Network Operations progressed and received input on use cases, architecture, and interfaces.

The OTNT Standardization Work Plan was updated and Issue 36 will be liaised to other SDOs.

A joint face-to-face interim meeting is planned with Q14/15 for 13-17 April 2026 in London. 

Q13/15 continued the work on requirements and solutions for time and frequency synchronization and updates to several Recommendations have been consented at this meeting.

G.8275 was revised to focus on PTP common aspects among the profiles. Time synchronization architectural aspects previously part of G.8275, have been moved into new recommendation G.8274.  Several enhancements to PTP profiles have been addressed in the consented revised G.8275.1 and G.8275.2. G.8273.2 Amendment 2 has been consented and includes new requirements (e.g., variable temperature-related requirements) and clarifications (e.g. on the impact on timing performance from new optical interfaces).

G.8262.1, the enhanced synchronous equipment clock, has been revised adding requirements at variable temperature. The G.781 (synchronization layer functions for synchronization over the physical layer) was revised together with G.8264 for better alignment between these two Recommendations concerning the specification of the physical layer synchronization status message (SSM). Further updates have been made in G.781.

A new Supplement dealing with synchronization in data centres has been released. It provides a comprehensive analysis of relevant requirements and synchronization solutions that can be implemented in data centres. Work on this topic will continue, also in coordination with other groups in IEEE and OCP dealing with related items.

Work has also been done on other recommendations planned to be consented in future SG15 plenaries. Work is progressing on the Recommendations on Primary Reference Time Clocks (G.8272, G.8272.1 and G.8272.2) with further clarification of the applicable requirements.

A new work item has been agreed to address monitoring aspects of the PRTC. A new work item has also been agreed to address a new PTP profile based on full timing support without the use of synchronous Ethernet (G.FTS-Lite). This might be suitable also for data centre applications.

Several other new work items have been approved to continue the work on most of the Recommendations consented at this meeting.

Q13/15 plans to hold an Interim meeting in presence in March 2025 and a series of virtual meetings on the synchronization in data centres. 

Liaisons have been exchanged with O-RAN concerning PRTC monitoring, and with IEEE and OCP concerning synchronization in data centres. 

Q14/15 continued the work on common transport management requirements and technology-specific (including OTN, MTN, Ethernet, MPLS-TP, Synchronization and Media) information models and YANG models. Nine amendments or revised Recommendations were consented, along with one corrigendum on G.8052.2.

Five new work items were created in total to revise the common equipment management function requirements, amend OTN management information model, revise optical media management, and initiate a new technical report on optical physical infrastructure resources management for transport networks.

The SG15 guidelines on making SG15 YANG modules available on the IETF's YANG repository, and draft guidelines for ITU-T Q14/15 draft Recommendations with UML and YANG models, were reviewed and updated.

Good progress was made on G.7713 Amd.1 Distributed call and connection management and G.7721 Amd.1 Synchronization management information model.

Q14/15 plans to hold one in person interim meeting with Q12 in April 2026, one joint correspondence activity with Q12 on GSTR.ENO, and three tracks of correspondence activities, including e-Meetings, to progress the work items. There will also be a joint correspondence activity with Q6 on the management of smart optical modules.

Two spontaneous liaisons on consented/agreed Recommendations and coordination on IM/DM with IEEE 802.1, IEEE PNCS (P1588), IEEE 802.3, MEF, IETF, BBF, TM Forum, Linux Foundation ONMI, O-RAN WG9, and one reply liaison to OIF on common information model were agreed.​

​

Decisions (ITU-T SG15, October 2025) 

Approval

WP1/15 - AAP Approval​

 Consent 

WP1/15 - Consent

WP2/15 - Consent

WP3/15 - Consent

WP1/15 - Agreement

WP2/15 - Agreement

​WP3/15 - Agreement

​