Meeting Executive Summary
11 - 22 February 2008
SG15 Chairman; Yoichi Maeda
Overview of the sixth SG 15 meeting of the study period 2005 - 2008
Geneva, 22 February 2008, the plenary meeting of Study Group 15 drew to a
close with agreement on a total of 40 new and revised texts including 1
approved Recommendation, 36 consented Recommendations and 3 agreed documents.
336 delegates represented 30 countries with 281 Contributions and 364
Temporary Documents. This was the biggest meeting of any Study Group
in this study period.
The meeting progressed work on Questions related to three key areas of
optical and metallic access networks, optical transport network technology
and structure, and progressed Lead Study Group activities on ANT and Optical
technologies. The meeting reviewed and updated the SG15 work programme and
discussed Liaison Statements from/to other groups including IEC, IETF, OIF
and IEEE to harmonize works with relevant bodies.
The meeting prepared SG15 reports to the TSAG correspondence group on study group
restructuring, ICTs and Climate Change issues, Promotion, DC-CET, Coordination and
Electronic Working Method (EWM) issues.
Key progress made in this SG15 meeting includes the first discussion among SG15
members on power saving and the SG’s approval of its restructuring proposal
and new question texts for the next study period.
The first early morning tutorial sessions on power saving were held over three days,
and each attracted more than 100 participants as described in the WP1 report. The
Chairman of SG15 expressed his thanks to Dave Faulkner and Andrew Nunn for their
contribution to the tutorial arrangement.
The meeting agreed the following mandate and work area and objectives for SG15 in the next study period:
The mandate of SG15 is to both continue and evolve studies on optical transport networks and access network infrastructures, systems, equipment, optical fibres, and the corresponding control plane technologies including metallic, optical and packet-based technologies with a clear focus on market requirements and drivers, technology innovation to enable the evolution towards future transport solutions. This encompasses the development of related standards for the in-premises such as home networking, access, metropolitan and long-haul sections of telecommunication networks. It was agreed to send SG15’s proposal on restructuring and new question texts for the next study period to TSAG for WTSA-08.
Another key achievement in this meeting was the SG15 agreement to establish an
Ad Hoc group on T-MPLS which resulted from an agreement for a collaborative approach for T-MPLS standardization. The meeting agreed to initiate the creation of a joint working team (JWT) involving appropriate experts from ITU-T and IETF to best leverage ITU-T and IETF design expertise and authority. The Chairman of SG15 expressed his thanks to Malcolm Betts and David Ward for their strong leadership and collaboration. Further details concerning this group can be found at:
In the closing plenary, a special event for the presentation of Certificates for
Vice-chairmen and Rapporteurs was organized to express thanks for their great
contribution to ITU-T SG15 activities.
The fourth networking event in SG15 was successfully organized with a support of
Wuhan Research Institute of Post and Telecommunications and attracted a lot of
participation on Thursday 7 June 2007. It was agreed that the networking event
would be held in the next SG15 meeting to facilitate communication and networking
amongst participants of the different Questions.
Changes of Rapporteurs, Editors and SG15 representatives
The updated list of Rapporteurs can be found at:
The updated list of Editors of the Recommendations can be found at:
The updated list of SG15 representatives and other roles can be found at:
Executive reports from WP chairmen and SG15 public relations coordinator
Working Party 1/15 - Optical and metallic access network
WP1 Chairman: Andrew Nunn
WP1/15 prepared one new Recommendation, two revised Recommendations, seven
Amendments and one Corrigendum for consent. In addition, one revised
Recommendation was submitted for approval following the resolution of
Additional Review comments.
In fulfilling its Access Network Transport (ANT) co-ordination role,
WP1/15 also updated the ANT Standards Overview (Issue 15) and the ANT Work Plan (Issue 14).
Draft new Recommendation G.984.6 on reach extension for Gigabit capable
Passive Optical Access Networks was completed by Q2/15. This
Recommendation is the latest edition to the G-PON series of optical access
system specifications. This document outlines the architecture and interface
parameters for GPON systems with extended reach using a physical layer
reach extension device, including regenerators or optical amplifiers. The
maximum physical reach is up to 60km, with loss budgets in excess of 27.5 dB
being achievable in both spans. This new capability will allow operators to
provide optical access service to areas that were previously out of reach,
and also explore new network designs for greater central office consolidation.
Work continued within Q4/15 on draft new Recommendation G.hn - Next generation
home networking transceivers, with over 30% of the Contributions to Q4/15 being
addressed to this topic.
Work also continued in Q1/15 on draft new Recommendation G.hnta on Home Network
transport architecture. It is anticipated that both G.hn and G.hnta will be
completed in December 2008.
The Additional Review comments addressed to draft revised Recommendation
G.984.4 - Gigabit-capable Passive Optical Networks (GPON): ONT Management and
Control Interface specification, were resolved by Q2/15 thus allowing it to be
approved in the closing SG15 plenary.
Revisions of the following Recommendations were completed:
Amendments to the following Recommendations were also completed:
- G.984.1 - Gigabit-capable Passive Optical Networks (GPON): General characteristic
- G.984.3 - Gigabit-capable Passive Optical Networks (G-PON): Transmission Convergence Layer Specification
Key work for 2008 includes:
- G.984.2 - Gigabit-capable Passive Optical Networks (GPON): Physical Media Dependent (PMD) layer specification
- G.984.4 - Gigabit-capable Passive Optical Networks (GPON): ONT Management and Control Interface specification
- G.992.3 - Asymmetric digital subscriber line transceivers 2 (ADSL2)
- G.992.5 - Asymmetric Digital Subscriber Line (ADSL) transceivers – Extended bandwidth ADSL2 (ADSL2plus)
- G.993.2 - Very high speed Digital Subscriber Line Transceivers 2
- G.994.1 - Handshake procedures for Digital Subscriber Line (DSL) transceivers
- G.997.1 - Physical layer management for digital subscriber line (DSL) transceivers
Under the auspices of WP1/15, SG15 held three power saving tutorial sessions. In order not
to reduce meeting time these were held between 0830 – 0930 on 13, 14 & 15 February. The sessions
were attended by more than 100 participants on each day and were judged a success in terms of raising
awareness of the issues. The programme for these sessions and presentations can be found at:
- Progression of draft new Recommendation G.hnta – Generic Home Network transport architecture
- Progression of draft new Recommendation G.gbe - Requirements for a 1Gbit/s point-to-point Ethernet-based fibre access system
- Progression of draft new Recommendation G.hn - Next generation home networking transceivers
- Progression of draft new Recommendation G.lt - Line Testing for Digital Subscriber Lines (DSL)
- Progression of draft new Recommendation G.inp - Impulse Noise Protection
- Progression of draft new Recommendation G.vector - Self FEXT cancellation
Working Party 2/15 - Optical transport network technology
WP2 Chairman: Gastone Bonaventura
WP2 prepared four revised Recommendations and one Amendment for consent as well
as one Supplement for Agreement. A Recommendation was proposed for deletion.
In the area of the optical fibres the revised version of Recommendation G.650.3
contains significant and technical changes aimed to give for each test a more
consistent structure, a guidance on typical wavelengths to test at and whether
the tests are carried out in one direction only or in both directions. Moreover
it has been proposed to delete G.651 mainly because with the approval of Rec.
G.651.1 the rather old and poorly maintained Rec. G.651 can be considered as being superfluous.
As for the optical systems, the revised version of Recommendation G.959.1 contains
many new inter-domain application codes for intra-office, short haul and long haul
systems, as well as for single-channel (up to 40 Gbit/s) and multi-channels
(at 2.5 Gbit/s and 10 Gbit/s up to 32 channels) systems.
As for the optical components and subsystems the new version of Recommendation G.666
has been updated in particular with a new text related to the measurements of
parameters of the polarization mode dispersion compensators. The Amendment to the
Recommendation G.671 is mainly devoted to the modifications of the parameter tables
for the passive chromatic dispersion compensators and the single optical channel
passive chromatic dispersion compensators.
In the optical fibre submarine cable area the revised Recommendations G.972 has been
made in order to insert the new definitions of the terms used in the Recommendation
G.978 on the submarine cables.
In the framework of WP2, the new Supplement G.Sup42 (Guide on the use of the ITU-T
SG15 Recommendations related to Optical Technology) has been submitted for Agreement
at this Plenary. This Supplement contains a Guide with an introduction to each category
of Recommendations on the optical technology and for each Recommendation is given a
short description of the purpose, of the content and, in many cases, also of the
evolution of the content in the subsequent versions.
Key ongoing work includes:
Moreover during this meeting a new interesting proposal for study has been made.
It has been proposed to start looking at physical implementations of short-reach
OTU4 interfaces and at associated sets of parameter values having in mind that
these short-reach OTU4 interfaces could be implemented as parallel lanes
(CWDM or DWDM) over a single fibre.
- the preparation of a new Supplement on general aspects of optical fibre and cable;
- a revision of G.698.2 with respect to the inclusion of 10 Git/s application
codes at 50 GHz channel spacing and of 40 Gbit/s application codes;
- a revision of G.Sup39 with a description of the characteristics of the
advanced modulation formats which are at present under consideration for the new
optical systems at 40 Gbit/s and beyond 100 Gbit/s;
- a work on the choice of the OTU4 bit rate, especially in relation to the choice of suitable modulation formats;
- the revision of G.671, in particular with respect PON splitter issues;
- the preparation of a new Recommendation on longitudinal compatible DWDM applications for repeaterless optical fibre submarine cables.
Working Party 3/15 – Optical transport network structure
WP3 Chairman: Stephen J. Trowbridge
WP3 prepared two new and ten revised Recommendations for consent, together with five
amendments and three corrigenda. A revised supplement and an amendment were prepared for agreement.
WP3 continued its progress in developing specifications for carrier grade packet transport technologies.
Work was completed on jitter limits and equipment tolerance for STM-256 interfaces (SDH 40 Gbit/s),
resulting in amendments to G.783 and G.825 and a corrigendum to G.8251.
- For T-MPLS, a new joint working team of experts has been formed across ITU-T and
IETF to best leverage the expertise of both groups. The ITU-T participation in this
team is provided through the T-MPLS ad hoc group, which was created and held its first
two days of meetings during the time of the SG15 plenary meeting.
- Carrier grade Ethernet is enhanced with a new Recommendation G.8032 for Ethernet ring protection switching.
- Carrier grade timing and synchronization in packet networks is improved with a revision of
G.8261 providing jitter and wander limits, equipment tolerance for timing at the boundary between
TDM and packet networks and defining the architecture of Synchronous Ethernet networks. An amendment
was developed for G.8262 regarding synchronous Ethernet equipment slave clocks, including the
restrictions that this can only be applied for full-duplex constant bit-rate Ethernet interfaces.
A new Recommendation G.8264 was completed regarding timing distribution through packet networks,
together with an enhancement to G.781 to extend Synchronous Status Messaging (SSM) to networks
based on Synchronous Ethernet as well as SDH and PDH.
- An amendment to the ASON architecture Recommendation G.8080 provides for application of
the ASON control plane to packet networks.
Work continues on network element management. In this meeting, revisions were completed to the
SDH and OTN network element management Recommendations G.784 and G.874. In addition, a revision
to the Data Communication Network Recommendation G.7712 was completed to add data-link layer
requirements of management and signaling communications channels.
In fulfilling its Optical Technology co-ordination role, WP3/15 updated the Optical Transport
Networks & Technologies Standardization Workplan (Issue 10). In addition, updates were completed
to the terminology Recommendations for SDH, OTN, ASON, and Ethernet transport
(G.780, G.870, G.8081, and G.8001).
Important ongoing and emerging work for WP3/15 into the next study period includes:
- Work on evolution of the Optical Transport Network, including higher speed interfaces to
support 40 Gbit/s and 100 Gbit/s Ethernet currently being standardized in the IEEE P802.3ba task force.
- New work to provide mechanisms for Time and Phase distribution over packet networks.
- The Ethernet Services Recommendations (G.8011 series) are being revised to better align
with the specifications of the Metro Ethernet Forum (MEF). The service architectures include
Ethernet private line, Ethernet virtual private line, Ethernet virtual private LAN, Ethernet
virtual private rooted multipoint, and Ethernet private LAN service.
- Work continues in Ethernet network architecture definition as part of the overall packet transport network specification.
SG15 public relations coordination
SG15 public relations coordinator: Shaohua Yu
SG15 received 17 other role and representative’s reports reflecting the highlights of other
SDO’ activities and proposed the following hot topics for promotion from consented texts or
important activity on Power saving tutorial sessions, Gigabit-capable Passive Optical Networks
(G-PON): Reach extension, Guide on the use of the ITU-T SG15 Recommendations related to optical
technology and Creation of T-MPLS Joint Working Team. You will see the news stories in ITU-T
E-flash news, which have resulted in some media interest and coverage. The meeting agreed update
seven Flyers: DSL, GPON, CWDM, Optical fibres and cables, Optical transport systems (OTS), ASON
and OTN, and create three new Flyers: DWDM, Ethernet and packet timing.
The 20 reply’s LSs for the outgoing LSs from the June 2007 SG15 plenary meeting, the 82 new
incoming LSs from SDO’s reply and the 26 relevant responses, as well as 43 new outgoing LSs
contained at the 11 – 22 Feb. 2008 SG15 meeting to reflect collaboration and coordination
relations with other SDO.
The second joint ITU-T/IEEE Workshop (19-20 June 2008, Geneva) is preparing based on the work of
Steering committee meeting. The SG15 provides preliminary information on the workshop titled
“Joint ITU-T/IEEE Workshop on Next Generation Optical Access Systems”. ITU-T and the IEEE
will hold a joint workshop on Next Generation Optical Access Systems.
NEXTComm, 16-19 June, 2008, Las Vegas will see ITU-T members, and guests stage an
interoperability showcase for both traditional FTTP-focused G-PON technology, as well
as emerging applications such as G-PON fed xDSL services, Enhancement band operation
(G.984.5), and G-PON Reach Extender demonstrations (G.984.re). ITU, together with Telcordia,
have collaborated to organize a multi-company interoperability demonstration. Any optical
access system, customer premises equipment, or G-PON device vendor with commercial products
compliant with G.984 series recommendations are eligible to participate in the Pavilion.
TD 283/GEN provides a status report on the planned ITU G-PON (G.984) Pavilion at NETXcomm 2008
(www.nxtcommshow.com) in Las Vegas, USA, 16-19 June, 2008.
It is agreed the text of the G.sup42 on "Guide on the use of the ITU-T Recommendations related to
Optical Technology", update “Access Network Transport overview and work plan” and “OTNT
standardization work plan”. These guiding documents could be used by developing countries as part
of type approval of services and systems and in developing national specific requirements for deploying
new networks and services.
Promotion, coordination and requirements for developing countries and countries with economies in
transition (DC-CET) were updated well, including the responses of “ITU-T activities on bridging
the standardization gap”, “Improve the Geographic Distribution of Workshops”
and “Assessment of ITU-T Recommendations in the light of Climate Change” from TSAG.
SG15 at a Glance
General areas of study on “Optical and other transport network infrastructures”
SG 15 is the focal point in ITU T for the development of standards on optical and other transport
network infrastructures, systems, equipment, optical fibres, and the corresponding control
plane technologies to enable the evolution toward intelligent transport networks.
This encompasses the development of related standards for the customer premises, access,
metropolitan and long haul sections of communication networks.
Lead study groups in specific areas of study to SG 15
In fulfilling its Access Network Transport (ANT) co-ordination role, WP1/15 also updated the ANT Standards Overview (Issue 15) and the ANT Work Plan (Issue 14).
Lead study group on access network transport
In fulfilling its Optical Technology co-ordination role, WP3/15 updated the Optical Transport
Networks & Technologies Standardization Workplan (Issue 10).
Lead study group on optical technology
Key objectives and results of this SG 15 meeting
Review the interim activities since June 2007
Progress the work of the Questions
Progress work on Lead Study Group issues on ANT and Optical technologies
Prepare texts of Recommendations for ‘Consent’ at the closing plenary
Prepare texts for ‘Agreement’ at the closing plenary
Deal with the approval of draft Recommendations, texts for Agreement and deletion of existing Recommendations
Process Liaison Statements from/to other groups
Plan interim activities
Review and update the Study Group 15 work programme
Review and update the SG15 representatives and other role’s activities
Prepare SG15’s comments on Study restructuring for the next study period to TSAG Correspondence Group
Prepare SG15’s comments on Coordination, Promotion and DC-CET issues to TSAG
Prepare SG15’s involvement in future workshops and external events
Prepare SG15’s material for promotion activities
SG15 meeting schedule for 2008
Next SG15 meeting (tentative); 1 – 12 December 2008, Geneva