INTERNATIONAL TELECOMMUNICATION UNION
TELECOMMUNICATION (01/2010) STANDARDIZATION SECTOR
SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS
Digital sections and digital line system – Optical line
systems for local and access networks
10 Gigabit-capable Passive Optical Network (XG-PON): General Requirements
This prepublication is an unedited version of a recently approved Recommendation.
It will be replaced by the published version after editing. Therefore, there will be
differences between this prepublication and the published version.
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Recommendation ITU-T G.987.1
10 Gigabit-capable Passive Optical Network (XG-PON):
This Recommendation addresses the general requirements of 10 Gigabit-capable Passive Optical Network (XG-PON) systems, in order to guide and motivate the physical layer and the transmission convergence layer specifications. The general requirements include examples of services, User Network Interfaces (UNI) and Service Node Interfaces (SNI), as well as the principal deployment configurations that are requested by network operators. This Recommendation also includes the system and operational requirements to meet the needs of supporting various business and residential applications.
As much as possible, this Recommendation maintains characteristics from [ITU-T G.982], [ITU-T G.983], and [ITU-T G.984] series of Recommendations. This is to promote backward compatibility with existing Optical Distribution Networks (ODN) that complies with those Recommendations. Furthermore, this recommendation provides a mechanism that enables seamless subscriber migration from Gigabit PON (Generic term to represent both G-PON and GE-PON) to XG–PON
using WDM defined in the G.984 series.
There are two flavours of XG-PONs based on the upstream line rate: XG-PON1 featuring a 2.5Gbit/s upstream path and XG-PON2 featuring a 10Gbit/s one. The initial phase of this specification only addresses XG-PON1. XG-PON2 will be addressed at later phase when the technology becomes more mature.
The following ITU-T Recommendations and other references contain provisions, which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation [ITU-T G.652] ITU-T Recommendation G.652 (2005), Characteristics of a single-mode
optical fibre cable.
[ITU-T G.657] ITU-T Recommendation G.657 (2006), Characteristics of a bending loss
insensitive single mode optical fibre and cable for the access network. [ITU-T G.902] ITU-T Recommendation G.902 (1995), Framework Recommendation on
functional access networks (AN) – Architecture and functions, access types,
management and service node aspects.
[ITU-T G.982] ITU-T Recommendation G.982 (1996), Optical access networks to support
services up to the ISDN primary rate or equivalent bit rates.
[ITU-T G.983.1] ITU-T Recommendation G.983.1 (2005), Broadband optical access systems
based on Passive Optical Networks (PON).
Rec. ITU-T G.987.1 (01/2010) – Prepublished version 1
[ITU-T G.983.2] ITU-T Recommendation G.983.2 (2005), ONT management and control
interface specification for B-PON.
[ITU-T G.983.3] ITU-T Recommendation G.983.3 (2001), A broadband optical access system
with increased service capability by wavelength allocation.
[ITU-T G.984.1] ITU-T Recommendation G.984.1 (2008), Gigabit-capable Passive Optical
Networks (GPON): General characteristics.
[ITU-T G.984.2] ITU-T Recommendation G.984.2 (2008), Gigabit-capable Passive Optical
Networks (GPON): Physical Media Dependent (PMD) layer specifications. [ITU-T G.984.3] ITU-T Recommendation G.984.3 (2008), Gigabit-capable Passive Optical
Networks (GPON): Transmission convergence layer specification.
[ITU-T G.984.4] ITU-T Recommendation G.984.4 (2008), Gigabit-capable Passive Optical
Networks (GPON): ONT management and control interface specification. [ITU-T G.984.5] ITU-T Recommendation G.984.5 (2007), Gigabit-capable Passive Optical
Networks (GPON): Enhancement band for Gigabit-capable Passive Optical
[ITU-T G.984.5Am1] ITU-T Recommendation G.984.5 Am1 (2009), Gigabit-capable Passive
Optical Networks (G-PON): Enhancement band. Amendment 1.
[ITU-T G.808.1] ITU-T Recommendation G.808.1 (2006), Generic protection switching –
Linear trail and subnetwork protection.
[ITU-T G.984.6] ITU-T Recommendation G.984.6 (2008), Gigabit-capable Passive Optical
Networks (GPON): GPON optical reach extension (G.984.re).
[ITU-T Y.2201] ITU-T Recommendation Y.2201 (2007), NGN release 1 requirements [ITU-T G.810] ITU-T Recommendation G.810 (1996), Definitions and terminology for
[ITU-T G.813] ITU-T Recommendation G.813 (2003), Timing characteristics of SDH
equipment slave clocks (SEC)
[ITU-T G.703] ITU-T Recommendation G.703 (2008), Physical/electrical characteristics of
hierarchical digital interfaces
[ITU-T G.8261] ITU-T Recommendation G.8261 (2008), Timing and synchronization aspects
in packet networks
[ITU-T G.8262] ITU-T Recommendation G.8262 (2008), Timing characteristics of synchronous
Ethernet equipment slave clock (EEC)
[ITU-T G.Sup45] ITU-T Series G Supplement45 (2009), Means and impact of GPON power
saving. White Paper
[ITU-T G.987] ITU-T Recommendation G.987 (2009), G.987 definitions, abbreviations and
[ITU-T G.987.2] ITU-T Recommendation G.987.2 (2009), 10-Gigabit-capable Passive Optical
Networks (XG-PON): Physical Media Dependent (PMD) layer specification [ITU-T Y.2001] ITU-T Recommendation Y.2001 (12/2004), General overview of NGN. [ITU-T Y.1731] ITU-T Recommendation Y.1731 (02/2008), OAM functions and mechanisms
for Ethernet based networks.
Rec. ITU-T G.987.1 (01/2010) – Prepublished version 2
[ITU-T J.185] ITU-T Recommendation J.185 (02/2002), Transmission equipment for
transferring multi-channel television signals over optical access networks by
[ITU-T J.186] ITU-T Recommendation J.186 (06/2003), Transmission equipment for multi-
hannel television signals over optical access networks by sub-carrier c
[IEEE 1588] IEEE 1588-2008 (2008), IEEE Standard for a Precision Clock Synchronization
Protocol for Networked Measurement and Control Systems
[DSLF TR-156] DSL Forum (also known as the Broadband Forum) TR-156 (2008) Using
GPON Access in the context of TR-101
[MEF 10.1] MEF 10.1 (2006), Ethernet Service Attributes Phase 2
See [ITU-T G.987], clause 3.
4 Abbreviations and Acronyms
See [ITU-T G.987], clause 4.
5 Architecture of the optical access network
5.1 Network architecture
The optical section of a local access network system can be either active or passive and its architecture can be either point-to-point or point-to-multipoint. Figure 5-1 shows the considered architectures, which range from Fibre to the Home (FTTH), Fibre to the Cell sites (FTTCell), Fibre to the Building/Curb (FTTB/C), to the Fibre to the Cabinet (FTTCab), etc. The Optical Distribution Network (ODN) is common to all architectures shown in Figure 5-1; hence the commonality of this system has the potential to generate large worldwide volumes.
Rec. ITU-T G.987.1 (01/2010) –