Committed to connecting the world

ITU-T Study Group 15 executive summary

 24 November - 5 December 2014
ITU-T Study Group 15
Networks, Technologies and Infrastructures for Transport, Access and Home
Study Group 15 Chairman: Stephen Trowbridge

Study Group 15 held its third meeting of the 2013-2016 study period in Geneva from 24 November to 5 December 2014, attended by 280 delegates representing 27 countries. The meeting received 371 Contributions and 463 TDs, a slight increase over the previous meeting. The meeting observed the 12-day Contribution deadline of revised Recommendation ITU-T A.1, and nearly all of the Contributions to this meeting were submitted using Direct Document Posting (DDP).

SG15 Approved four texts (three new Recommendations and one amendment) and Consented 42 texts (three new Recommendations, 19 revised Recommendations, 15 amendments, and five corrigenda). Agreement was reached on three amendments, one new supplement, an implementer’s guide and a covering note. One especially noteworthy accomplishment was the Approval of new Recommendation ITU-T G.9701 Fast Access to Subscriber Terminals ( - Physical layer specification.

SG15 authorized 15 interim Rapporteur group meetings to be held prior to the next SG15 plenary, 16 virtual meetings, and generated 43 liaison statements.
The next plenary meeting of SG15 will be held 22 June - 3 July 2015 in Geneva.

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

Executive reports from WP Chairmen

WP1/15 – Transport aspects of access, home and smart grid networks
WP1 Chairman: Tom Starr

Q1/15 revised and produced new version of the Access Network Transport (ANT) Standards Overview and Work Plan documents. The Home Network Transport (HNT) Standards Overview and Work Plan document was revised. The list of CIT activities in other organizations related to technologies based on Recommendations from WP1/15 was updated.

Q2/15 worked on several documents in the ITU-T G.989 series.  ITU-T G.989.2 was slightly refined, in order to get Approval at this meeting. ITU-T G.9802 (G.multi) was prepared for Consent and ITU-T G.9801 Implementer’s Guide for agreement.
A new cross-Question issue was introduced on Indoor Visible Light. It seems that Q2, 15 and Q18/15 each could bring relevant expertise to this issue. A joint meeting is will be held at our next opportunity, and further Contributions invited.

For Q4/15, the main meeting focus was on further updating draft ITU-T G.9701 ( PHY) and draft ITU-T G.997.2 ( OAM). The new ITU-T G.9701 (and related ITU-T G.994.1 Amd.4) was prepared for Approval at the SG15 closing plenary. New ITU-T G.997.2 was prepared for Consent at the SG15 closing plenary.

Q15/15 discussions focused on the ongoing Smart Home work item, and revised ITU-T G.9959 was prepared for Consent. Q15/15 agreed on initiating a new Recommendation ITU-T that specifies an improved mode of operation of ITU-T G.9904, and agreed on an update of the Smart Grid Overview and Work Plan.

Q18/15 finalized resolution of LC2 comments on draft ITU-T G.9979 and prepared draft text for Approval. Draft revisions to ITU-T G.9960, ITU-T G.9961 and ITU-T G.9963 were prepared. An initial skeleton draft text for proposed new Recommendation ITU-T G.996sa (secure admission) was agreed. A joint session with Q4/15 on DSL and PLC interference mitigation was held. A proposed technical paper on “Operation of technology over access and in-premises phone line medium” was addressed.

WP2/15 – Optical technologies and physical infrastructures
WP2 Chairman: Francesco Montalti

Q5/15: Progress was made in the revision of  ITU-T G.650.1. Indeed feedback from IEC SC86A/WG1 is expected on launching conditions for MFD and attenuation coefficient measurements before the June/July 2015 SG15 meeting. In a joint meeting with Q6/15 on chromatic dispersion, Q5/15 agreed to examine the chromatic dispersion characteristics of existing ITU-T G.652 fibre for deriving a pair of equation curves providing the minimum and maximum dispersion as a function of wavelength over the operation range.  This examination will be conducted including ITU-T G.657.A. Work will progress on ITU-T G.650.1, ITU-T G.650.2, ITU-T G.650.3, ITU-T G.652, ITU-T G.654 and ITU-T G.657 (expected for Consent at the February 2016 SG15 meeting).

Q6/15: The revised ITU-T G.695 was finalized for Consent.
Progress was made on the revision of ITU-T G.680, ITU-T G.959.1, ITU-T G.697, ITU-T G.698.2, ITU-T G.664, ITU-T G.metro, ITU-T G.Sup39. For the future the following activities are expected:
Progress draft revised ITU-T G.959.1 towards Consent at the June/July 2015 SG15 plenary meeting; establish sets of parameters and associated values to enable multi-vendor interoperability for the various modulation formats for 40G and 100G application codes in a revision of ITU-T G.698.2; establish sets of parameters and associated values to enable multi-vendor interoperability for low-cost metro applications for inclusion in new ITU-T G.metro on the basis of wavelength-agnostic endpoints.

Q7/15 : The revised ITU-T L.36 was finalized for Consent. A base text of new ITU-T L.fmc was drafted to be used for progressing the work by means of correspondence activity, coordinated by the Editor with the objective to further improve the text of ITU-T L.fmc and harmonize it with the related IEC standards. Regarding the revision of ITU-T G.671, Contributions are invited to enhance the text and parameter definitions to allow for flexible grid applications and for adding new optical components that are especially used for optical interfaces using advanced modulation formats in order to support Q6/15 activities on 40G and 100G application codes.  In respect to ITU-T G.672, Contributions with specific text proposals about enhancements towards flexible grid technology are invited for future meetings.

Q8/15: The revised ITU-T G.977 was finalized for Consent.
Progress was made on the revision of the relevant Recommendations considering 100G applications. The meeting decided to give priority to the revision of ITU-T G.973 following the revision of ITU-T G.977 and to progress discussion through correspondence with a view to Consent at the September 2016 meeting. It was agreed to start discussion on the revision of ITU-T G.Sup41 according to the update of ITU-T G.977 and also decided that the revision date be set to at same as or after that of ITU-T G.973 to reflect its updated contents.

Q16/15: ITU-T L.10, ITU-T L.26 and ITU-T L.43 will be revised in compliance with the relevant IEC normative texts. An action plan was approved in order to possibly reach Consent at the SG 15 meeting in June/July 2015. A correspondence group will consider Contributions and develop the text of the new draft revised ITU-T L.91.
The activities on the new ITU-T L.oxcon and ITU-T L.pneid and on the revision  of ITU-T L.59 and ITU-T L.60 will be carried out by correspondence.

Q17/15: New ITU-T L.94 (ex L.gpsm) and revised ITU-T L.25 were agreed for Consent.

WP3/15 – Transport network characteristics
WP3 Chairman: Ghani Abbas

In its third meeting in the study period WP3/15 successfully progressed the work on a number of Recommendations and presented twenty documents for Consent, including eight revised Recommendations, ten amendments and two corrigenda. In addition two amendments and one supplement were agreed. WP3 also initiated activity on three new Recommendations addressing the common control aspects of the use of SDN in the transport network, the timing characteristics of primary reference clocks and the timing characteristics of slave reference clocks.

In fulfilling its Optical Technology and Optical Transport Network coordination role, WP3/15 updated the Optical and other Transport Networks & Technologies Standardization Work Plan.

Considerable progress was made on a number of transport network technology fronts, including OTN beyond 100G, SDN in Transport networks, OTN protection, Ethernet OAM and Equipment specifications for Packet-based Transport Networks, Transport network architecture, timing and frequency transport, generic and technology-specific Transport equipment management requirements, automatic discovery, information models and TSDN.

In the area of network restoration and protection, a revision was prepared for ITU-T G.8031 (Ethernet linear protection switching) and an amendment was agreed to ITU-T G.873.1  (Optical Transport Network (OTN): Linear protection). Continued progress was made on ODU shared mesh protection (ODU SMP), Multi-domain Segmented Protection (MDSP).
In the area of interfaces for OAM and packet equipment, revisions of ITU-T G.8011 (Ethernet service characteristics), ITU-T G.8021 (Characteristics of Ethernet transport network equipment functional blocks) were prepared and an amendment was produced to ITU-T G.8013 (OAM functions and mechanisms for Ethernet based networks). A corrigendum was prepared for ITU-T G.8112 (Interfaces for the MPLS Transport Profile layer network). Additionally, a new ITU-T G.Supp 53 providing guidance on Ethernet OAM performance monitoring was prepared and work was progressed on MPLS-TP OAM and equipment. The MPLS-TP terminology ITU-T G.8101/Y.1355 was revised.

In the area of Optical Transport Network (OTN), progress was made on B100G where working assumptions and LLs were updated. Additionally, work on transport of CPRI over OTN was progressed. Amendments to ITU-T G.709, ITU-T G.7041, ITU-T G.8201 and ITU-T G.783 were produced and submitted for Consent.

Considerable progress was made on SDN topics and a new work item on Common Control Aspects was agreed.

Significant progress was also made on transport of frequency, time and phase over packet networks, where it was agreed to move forward to Consent the following:
ITU-T G.8273.2 Amd.1, ITU-T G.8273 Amd.1, ITU-T G.8262, ITU-T G.8272, ITU-T G.8261 Amd.1, ITU-T G.8271 Amd.2, ITU-T G.8271.1 Amd.2, ITU-T G.8275.1 Cor.1, ITU-T G.8264 Amd.1, ITU-T G.8275 Amd.1. Further progress was made on the definition of the phase and time transport. It was agreed to initiate work on two new items: 

  • ITU-T G.8262.1, Timing characteristics of enhanced synchronous Ethernet equipment slave clock.
  • ITU-T G.8272.1, Timing characteristics of an enhanced Primary Reference Time Clock.

In the area of management and control of transport systems and equipment, the following were produced for Consent:

Revised ITU-T G.8151, Management aspects of the MPLS-TP network element.
Revised ITU-T G.7714.1, Protocol for automatic discovery in transport networks.

Good progress was made on the generic and technology-specific transport equipment management requirements and information models.

The latest SG15 Rapporteur meeting plan is at:

The latest Status of Recommendations is reflected in the Work Programme at:


Previous meetings