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SG15 Last Meeting Executive Summary

​29 January - 9 February 2018
ITU-T Study Group 15
Networks, Technologies and Infrastructures for Transport, Access and Home

Study Group 15 held its second meeting of the 2017-2020 study period in Geneva from 29 January-9 February 2018, attended by 268 delegates representing 29 countries.

The meeting received 344 contributions and 427 TDs, a slight decrease from 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).

The meeting was preceded by a Saturday workshop on 27 January 2018, Building Tomorrow's Networks, including 177 experts from ITU-T SG15 and the IEEE 802.1 and 802.3 Working Groups, following meetings of IEEE 802.1 and 802.3 that were held in Geneva from 22-26 January 2018. Topics of the workshop included New High-Speed and Long Reach Optical Interfaces, Passive Optical Networking, Mobile fronthaul, 5G mobile transport, Management, YANG, and Data Modeling. Presentations from the workshop are available at Programme and takeaways documented at Workshop Outcomes.

Some important results of the SG15 meeting include:

  • A new Technical Report GSTR-TN5G, Transport network support of IMT-2020/5G, was agreed (see also the Communiqué). This report captures requirements for Transport Network support of 5G mobile fronthaul, middle-haul, and backhaul networks. This report contains a synthesis of requirements developed from sources including 3GPP, the CPRI cooperation, and mobile network operator inputs. This will form the foundation for specifying how to apply SG15 technologies, including PON and OTN, to meeting 5G mobile network transport requirements.
  • A new Recommendation G.7702 was finalized on the Architecture for SDN control of transport networks.
  • A new Supplement G.Suppl.62 on G.fast certification, an important element of the G.fast certification program being carried out by BBF.

SG15 approved one new Recommendation and two new Amendments, consented 49 texts (8 new Recommendations, 10 revised Recommendations, 20 Amendments, and 11 Corrigenda). Agreement was reached on two new and four revised Supplements, two Implementer's guides, and on a new Technical Report.

SG15 authorized 12 interim face-to-face Rapporteur group meetings to be held prior to the third SG15 plenary of the 2017-2020 study period, 23 virtual meetings, and generated 35 liaison statements. The third plenary meeting of SG15 in the 2017-2020 study period is scheduled 8-19 October 2018 in Geneva.

SG15 agreed to the discontinuation of Q3/15, reassigning responsibility for update of the OTNT Standardization Workplan to Q12/15, and reallocating responsibility for terminology to the appropriate other questions of WP3/15.

In fulfilling its lead study group responsibilities, SG15 revised the Access Network Transport (ANT) standards overview and work plan, the Optical Transport Networks and Technologies (OTNT) standardization work plan, the Home Network Transport (HNT) Standards Overview and Work Plan, and the Smart Grid 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; WP1 Vice-Chairman: Hubert Mariotte

Q1/15 updated the Access Network Transport (ANT) Standards Overview and Work Plan documents.  A web-based ANT Roadmap demonstration received support for further development. The Home Network Transport (HNT) Standards Overview and Work Plan document was revised. The list of CIT activities in other organizations related to the WP1/15 Recommendations was updated.

Q2/15 worked on Passive Optical Networks (PON), preparing G.984.5 Amd. 1 for consent, and two supplements for agreement.  Q2/15 proposed to start work on five new projects on higher speed access systems. Q2/15 met jointly with Q11/15 and Q12/15, developing a joint view on access for 5G wireless.

Q4/15 worked on access via metallic conductors, focusing on G.fast, the next-generation G.mgfast, and VDSL2.  12 texts were prepared for Consent, and G.Suppl.62 on G.fast Certification is provided for agreement.

Q15/15 met under the chairmanship of Associate Rapporteur Paolo Treffiletti, addressing Smart Grid access.  G.9958 was prepared or Consent.  A joint session of Q15/15 and Q18/15 discussed the potential application of G.hn for smart grid.

Q18/15 worked on the G.hn family of recommendations, Visible Light Communication (G.vlc) and Optical Camera Communication (G.occ).  Three texts were prepared for Consent.  A joint session with Q4/15 address the possible coordination between access and in-home standards.

WP2/15 – Optical technologies and physical infrastructures
WP2 Chairman: Noriyuki Araki; WP2 Vice-Chairman: Pete Anslow

Q5/15 worked on characteristics and test methods of optical fibres and cables and consented revised Recommendation G.650.1 "Definitions and test methods for linear, deterministic attributes of single-mode fibre and cable" and agreed revised G.Suppl.59 "Guidance on optical fibre and cable reliability".

Q6/15 worked on characteristics of optical systems for terrestrial transport networks and consented new Recommendation G.698.4 "Multichannel bi-directional DWDM applications with port agnostic single-channel optical interfaces" and revised Recommendations G.695 and G.959.1.  Q6/15 made progress on the draft of revised G.698.2, which has now been agreed to also include 100 Gbit/s interfaces appropriate for 80 km distance, towards consent at the October 2018 meeting. Q6/15 also agreed to start work on a future revision of G.698.2 for adding application codes for 200G and 400G.

Q7/15 worked on optical component specifications and made progress on the draft of revised G.672 "Characteristics of multi-degree reconfigurable optical add/drop multiplexers" toward consent at the October 2018 meeting.

Q8/15 worked on optical fibre submarine cable systems and agreed revised G. Suppl.41, which contains design guidelines for optical fibre submarine cable systems adopted for high bit-rate coherent systems.

Q16/15 worked on optical physical infrastructures and consented new Recommendation L.207 "Passive node elements with automated ID tag detection" and revised Recommendations L.108 and L.156. Progress was also made on new Recommendations related to optical fibre cable construction, installation methods and optical infrastructures, such as optical fibre distribution box and optical fibre cables for in-home application.

Q17/15 worked on maintenance and operation of optical fibre cable networks and consented new Recommendation L.315 "Water detection in underground closures/cabinets for the maintenance of optical fibre cable networks with optical monitoring system".

WP3/15 – Transport network characteristics
WP3 Chairman: Malcolm Betts; WP3 Vice-Chairman: Glenn Parsons

Q3/15 Updated the Optical Transport Networks & Technologies Standardization Work Plan (OTNT SWP).
Considering the decline in the work within the scope of Q3/15, SG15 agreed to propose the deletion of Q3/15 with the maintenance of the OTNT SWP and the coordination responsibilities being moved to Q12/15.

Q9/15 consented amendments to G.808 "Terms and definitions for network protection and restoration" and G.8031 "Ethernet linear protection switching", initiated new work on an amendment to G.8131 "Linear protection for MPLS transport profile" to align with the most recent RFCs, and continued work on the revision of G.808.2 "Generic protection switching – ring protection" and new Recommendation G.mtdh "MPLS-TP dual-homing protection".

Q10/15 consented G.8013/Y.1731 (2015) Corrigendum 1, consented revised G.8021 (in part to align with Q11/15's new G.8023), and progressed work on MPLS-TP equipment (in part to add Client Signal Fail support) and on amending G.8013. Future work is planned to revise G.8011 to align with MEF 3.0 and complete the G.8013 amendment and the G.8121 series revision.

Q11/15 focused much of the meeting on topics related to IMT2020/5G Transport networks, and approved two new work items in that area.  Q11/15 consented three new recommendations, two amendments, one revision and two corrigenda, and agreed one supplement.  Two of the new recommendations define a hard-decision FEC with higher coding gain, G.709.2 for the OTU4, and G.709.3 FlexO interfaces. that are used for OTN signals with rates higher than 100Gbit/s.  The third new recommendation was G.8023 "Characteristics of equipment functional blocks supporting Ethernet physical layer and FlexE interfaces".  A revision to the G.709.1 short-reach FlexO interface was also consented, along with amendments to G.709 and G.798.  The newly agreed G.Sup58 describes multi-lane electrical interfaces that can be used with OTN and FlexO.  Q11/15 plans one interim meeting in June 2018 to progress work on IMT2020/5G transport and other work items.

Q11/15 and Q12/15 together with experts from WP1/15, completed the first version of a Technical Report (GSTR TN5G) on “Transport network support of IMT‑2020/5G.

Q12/15 continued its work on architecture for SDN control of transport networks jointly with Q14/15. New Recommendation G.7702 "Architecture for SDN control of transport networks" (Q12/15) and an amendment to G.7711 "Generic protocol-neutral management Information Model for Transport Resources" (Q14/15) were consented. These Recommendations provide the foundation for SG15 to define the interface from the Transport Network to the 3GPP management system and, in particular, support 5G network slicing.  Future work is planned on architecture for media networks and generalizing management architecture.

Q13/15 continued its investigating the evolving requirements for networks synchronization to support IMT-2020/5G. The current view of these requirements is provided in GSTR TN5G. Q13/15 is working with the CPRI cooperation on the definition of synchronization for the fronthaul network.  Good progress was made on the analysis of the solutions for accurate time synchronization delivery (including the definition of enhanced synchronous Ethernet clock to be specified in G.8262.1). Progress has been made on the clock for partial timing support, G.8273.4 (planned for consent in October 2018). Work has also initiated on "coherent network PRTC", a concept based on mutual synchronization, which provides both higher accuracy and higher reliability in the upper layer of the time synchronization network.  Eight documents were consented at this meeting, among these, an important amendment to the G.8271.2, network limits for partial timing support. Q13/15 plans to hold an interim meeting in June 2018.

Q14/15 consented the revision of G.8051 "Management aspects of the Ethernet Transport (ET) capable network element" and G.7711 "Generic protocol-neutral management Information Model for Transport Resources". It also made progress on DCN (G.7712) and management of OTN (G.874, G.874.1), Transport Ethernet (G.8052, G.8052.1), MPLS-TP (G.8151, G.8152), Synchronization (G.sync-mgmt), and Media (G.media-mgmt). It started a new work item on G.8052.2 "Resilience Information & Data models for Transport Ethernet". Q14/15 plans to hold two interim meetings in May and August in 2018.  Q14/15 is working in cooperation with IEEE 802.1, IEEE 802.3, ONF, MEF, BBF, and IETF to provide consistent information models and YANG data models for Ethernet. Q14/15 is hosting monthly virtual meetings to coordinate activity. This work follows on from the successful Joint IEEE 802 and SG15 Workshop and the 28 January 2018 Q14/15 Rapporteur Group Meeting with experts from IEEE 802.1 and 802.3.

Decisions (ITU-T SG15, February 2018)

Approval

WP1/15 – TAP Approval

Recommendations

N=new/R=rev.

TitleText in  Doc(s)
None   

WP2/15 - TAP Approval

Recommendations

N=new/R=rev.

TitleText in  Doc(s)
None   

WP3/15 - TAP Approval

Recommendations

N=new/R=rev.

TitleText in  Doc(s)
None   

WP1/15 - AAP Approval

RecommendationN=new/R=rev.TitleText in  Doc(s)
G.993.2 (2015) Amd.3NVery high speed digital subscriber line transceivers 2 (VDSL2) - Amendment 3TD177/P
G.9961 (2015) Amd.3NUnified high-speed wire-line based home networking transceivers - Data link layer specification: Amendment 3TD193R1/P
G.9978NSecure admission in G.hn networkTD196R1/P

WP2/15 - AAP Approval

Recommendations

N=new/R=rev.

TitleText in Doc(s)
None   

WP3/15 - AAP Approval

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
None   

Determination

WP1/15 - Determination

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
None   

WP2/15 - Determination

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
None   

WP3/15 - Determination

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
None   

Consent

WP1/15 - Consent

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
G.984.5 (2014) Amd.1NGigabit-capable passive optical networks (GPON): Enhancement band TD185R2/P
G.993.2 Amd.4NVery high speed digital subscriber line transceivers 2 (VDSL2) (2015)TD178R1/P
G.993.5 Cor.2NSelf‑FEXT cancellation (vectoring) for use with VDSL2 transceivers (2015)TD179R1/P
G.994.1 Amd.2NHandshake procedures for digital subscriber line transceivers (2017)TD210/P
G.997.1 Amd.1NPhysical layer management for digital subscriber line transceivers (2016)TD198R1/P
G.997.1 Cor.1NPhysical layer management for digital subscriber line transceivers (2016)TD199/P
G.997.2 Amd.5NPhysical layer management for G.fast transceivers (2015)TD200R1/P
G.997.2 Cor.4NPhysical layer management for G.fast transceivers (2015)TD201R1/P
G.998.2 Cor.1NEthernet-based multi-pair bonding (2005)TD209/P
G.996.2 Cor.1NSingle-ended line testing for digital subscriber lines (DSL) (2009)TD203R1/P
G.996.2 Amd.6NSingle-ended line testing for digital subscriber lines (DSL) (2009)TD202R1/P
G.9701 Cor.5NFast access to subscriber terminals (G.fast) - Physical layer specification (2014)TD191R1/P
G.9701 Amd.5NFast access to subscriber terminals (G.fast) - Physical layer specification (2014)TD192R2/P
G.9960 Cor.4NUnified high-speed wire-line based home networking transceivers – System architecture and physical layer specification: Corrigendum 4TD222/P
G.9961 Amd.4NUnified high-speed wireline-based home networking transceivers – Data link layer specification: Amendment 4TD194R1/P
G.9961 Cor.5NUnified high-speed wireline-based home networking transceivers – Data link layer specification: Corrigendum 5TD195/P
G.9958NGeneric architecture of home networks for energy managementTD175R2/P

WP2/15 - Consent

RecommendationsN=new/ R=rev.TitleText in  Doc(s)
G.650.1RDefinitions and test methods for linear, deterministic attributes of single-mode fibre and cableTD187R3/P

G.698.4

(ex G.metro)

NMultichannel bi-directional DWDM applications with port agnostic single-channel optical interfacesTD182R2/P
G.695ROptical interfaces for coarse wavelength division multiplexing (CWDM) applicationsTD115R2/P
G.959.1ROptical transport networks physical layer interfacesTD117R1/P
L.108 (ex L.79)ROptical fibre cable elements for microduct blowing-installation applicationTD188R3/P
L.156 (ex L.57)RAir-assisted installation of optical fibre cableTD186R2/P
L.207 (ex L.pneid)NPassive node elements with automated ID tag detectionTD168R2/P
L.315 (ex L.wdc)NWater detection in underground closures for the maintenance of optical fibre cable networks with optical monitoring systemTD171R1/P

WP3/15 - Consent

RecommendationN=new/ R=rev.TitleText in Doc(s)
G.808 Amd.1NTerms and definitions for network protection and restorationTD172R1/P
G.8031 Amd.1NEthernet linear protection switchingTD116R1/P
G.8013/Y.1731
Cor .1
NOAM functions and mechanisms for Ethernet-based networks: Corrigendum 1TD166R1/P
A.5 in
TD215/P
G.8021/Y.1341 RCharacteristics of Ethernet transport network equipment functional blocksTD156R1/P
A.5 in
TD212/P
G.709.2 (ex G.709.otu4lr)NStrong HD for OTU4TD173R2/P
G.709.3
(ex G.709.flexo-lr)
NFlexO for longer reach interfacesTD162R2/P
A.5 in
TD213/P
G.709/Y.1331 (2016) Amd.2NInterfaces for the Optical Transport Network (OTN): Amendment 2TD161R1/P
A.5 in
TD223/P
G.709.1/Y.1331.1RFlexible OTN short-reach interfaceTD167R1/P
A.5 in
TD214/P
G.798 Amd.1NCharacteristics of optical transport network hierarchy equipment functional blocksTD157R1/P
A.5 in
TD211/P
G.798 Cor.1NCharacteristics of optical transport network hierarchy equipment functional blocksTD207/P
G.7041/Y.1303
Cor 1
NGeneric framing procedure: Corrigendum 1TD219/P
G.8023NCharacteristics of equipment functional blocks supporting Ethernet physical layer and FlexE interfacesTD152R1/P
A.5 in
TD204R1/P
G.7701 Amd.1NCommon control aspectsTD114R1/P
G.7702 (ex G.asdtn)NArchitecture for SDN control of transport networksTD111R1/P
G.8264/Y.1364 Amd.1NDistribution of timing information through packet networksTD190R1/P
G.8266/Y.1376 Amd.1NTiming characteristics of telecom grandmaster clocks for frequency synchronizationTD169R1/P
G.8271 (2017) Amd.1NTime and phase synchronization aspects of telecommunication networks - Amendment 1TD158R1/P
G.8271.1/Y.1366.1 Amd.1NNetwork limits for time synchronization in Packet networks - Amendment 1TD159R1/P
G.8271.2/Y.1366.2 Amd.1NNetwork limits for time synchronization in packet networks with partial timing support from the network - Amendment 1TD160R1/P
G.8273/Y.1368RFramework of phase and time clocksTD113R1/P
G.8275.1/Y.1369.1 (2016) Amd.2NPrecision time protocol telecom profile for phase/time synchronization with full timing support from the network: Amendment 2TD184/P
G.8275.2/Y.1369.2 (2016) Amd.2NPrecision time Protocol Telecom Profile for time/phase synchronization with partial timing support from the network: Amendment 2TD170R1/P
G.7711RGeneric protocol-neutral management Information Model for Transport ResourcesTD163R1/P
G.8051/Y.1345 RManagement aspects of the Ethernet Transport (ET) capable network elementTD164R1/P
A.5 in
TD221/P

Agreement

WP1/15 - Agreement

Doc. #/  Ref.N=new/ R=rev.TitleText in Doc(s)
G.suppl.TCadaptNG.sup.TCadapt draft (for agreement) TD153R1/P
G.suppl.HSPNG.sup.HSP draft (for agreement) TD154R1/P
G.suppl.62NG-series Supplement 62 on Gfast certification (new)TD176R2/P

WP2/15 – Agreement

Doc. #/  Ref.N=new/ R=rev.TitleText in Doc(s)
G.suppl.59RGuidance on optical fibre and cable reliabilityTD155R2/P
G.suppl.41RDesign guidelines for optical fibre submarine cable systemsTD183R1/P

WP3/15 - Agreement

Doc. #/  Ref.N=new/ R=rev.TitleText in Doc(s)
G.808.1 Imp. GuideNGeneric protection switching - linear protectionTD180/P
G.808.2 Imp.GuideNGeneric protection switching - ring protectionTD181R1/P
G.supl.58RDraft revised Supplement 58 (v3.0) to ITU-T G-series RecommendationsTD151R1/P
GSTR-TN5GNTransport network support of IMT-2020/5GTD189R1/P