10G-PON (also known as XG-PON or G.987) is a 2010

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...

ing standard for data links, capable of delivering shared Internet access rates up to 10 Gbit/s (gigabits per second) over existing

dark fiber A dark fibre or unlit fibre is an unused optical fibre, available for use in fibre-optic communication. Dark fibre may be leased from a network service provider. Dark fibre originally referred to the potential network capacity of telecommunic ...

. This is the

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Comm ...

's next generation standard following on from

GPON G.984, commonly known as GPON (gigabit-capable passive optical network), is a standard for passive optical networks (PON) published by the ITU-T. It is commonly used to implement the outermost link to the customer (last kilometre or last mile) o ...

or Gigabit-capable PON. Optical fibre is shared by many subscribers in a network known as

FTTx Fiber to the ''x'' (FTTX; also spelled "fibre") or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber op ...

in a way that centralises most of the

telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...

equipment, often displacing copper phone lines that connect premises to the phone exchange.

Passive optical network A passive optical network (PON) is a fiber-optic telecommunications technology for delivering broadband network access to end-customers. Its architecture implements a point-to-multipoint topology in which a single optical fiber serves multiple e ...

(PON) architecture has become a cost-effective way to meet performance demands in

access network An access network is a type of telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to one another. The access network may be further ...

s, and sometimes also in large optical local networks for "Fibre-to-the-desk". Passive optical networks are used for the "Fibre-to-the-home" or "Fibre-to-the-premises" last mile with splitters that connect each central transmitter to many subscribers. The 10 Gbit/s shared capacity is the downstream speed broadcast to all users connected to the same PON, and the 2.5 Gbit/s upstream speed uses multiplexing techniques to prevent data frames from interfering with each other. Users have a network device that converts optical signals to the signals used in building wiring, such as

Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...

and wired analogue

plain old telephone service Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from 1 ...

. XGS-PON is a related technology that can deliver upstream and downstream (symmetrical) speeds of up to 10 Gbit/s (gigabits per second).

Standards

G.987 is the standard for 10G-PON. Asymmetric 10G-PON is specified as XG-PON1: 10 Gbit/s downstream and 2.5 Gbit/s upstream (nominal line rate of 9.95328 Gbit/s downstream and 2.48832 Gbit/s upstream). Symmetric 10G-PON is also proposed as XG-PON2 with 10 Gbit/s upstream, but would require more expensive burst-mode

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fi ...

s on optical network terminals (ONTs) to deliver the upstream transmission speed. Another symmetric 10G-PON standard is XGS-PON (ITU-T G.9807.1, approved 2016-06-22). Framing is "G-PON like" but uses different wavelengths from G-PON (using a WDM to separate them) so that G-PON subscribers can be upgraded to 10G-PON incrementally while GPON users continue on the original OLT. The G-PON standard is

G.984 G.984, commonly known as GPON (gigabit-capable passive optical network), is a standard for passive optical networks (PON) published by the ITU-T. It is commonly used to implement the outermost link to the customer (last kilometre or last mile) ...

. This compares to the

IEEE The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operat ...

802.3av standard for

10G-EPON The 10 Gbit/s Ethernet Passive Optical Network standard, better known as 10G-EPON allows computer network connections over telecommunication provider infrastructure. The standard supports two configurations: ''symmetric'', operating at 10 Gbit/s d ...

based on

, which has standardised upstream rates of both 1Gbit/s and 10Gbit/s. The 10 Gigabit PON wavelengths (1577 nm down / 1270 nm up) differ from GPON and EPON (1490 nm down /1310 nm up), allowing it to coexist on the same fibre with either of the Gigabit PONs.George, John. "PONs Can Keep Pace with Exploding Bandwidth Demand" - FTTH Prism: Vol. 7, No. 2, July 2010
retrieved 06 Nov 2010

G.987

Recommendation G.987 is a family that defines this access network standard (referred to as XG-PON). It comprises four recommendations: * '
G.987
'': 10-Gigabit-capable passive optical network (XG-PON) systems: Definitions, Abbreviations, and Acronyms, 2010. * '
G.987.1
'': General requirements of 10G-PON systems ''(approved 2010-01-13)''. Includes examples of services, user network interfaces (UNIs) and service node interfaces (SNIs), as well as the principal deployment configurations that are requested by network operators. * '
G.987.2
'': Physical media dependent (PMD) layer specification ''(approved 2010-01-13, updated 2010-10-07)''. Describes a flexible optical fibre access network representing an evolutionary development from G.984.2, asymmetric only in the current version. * '
G.987.3
'': Transmission convergence (TC) specifications ''(approved 2010-10-07)''.

G.988

There is also a companion ITU-T standard defining a management and control interface for administering optical network units, referred to by the G.987 recommendations. * '
G.988
'': ONU management and control interface (OMCI) specification ''(approved 2010-10-07)''.

ONU equipment

The

optical network unit Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

(ONU) supplies network services from the PON to customer premises, connecting

customer-premises equipment In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation po ...

such as a home gateway or office firewall. An

optical network terminal upTwo simple NIDs, carrying six lines each, on the outside of a building upA German copper phone line termination box called '' Abschlusspunkt LinienTechnik'' (APL, " Demarcation point") In telecommunications, a network interface device (NID; ...

(ONT) is an ONU that functions as a

demarcation point In telephony, the demarcation point is the point at which the public switched telephone network ends and connects with the customer's on-premises wiring. It is the dividing line which determines who is responsible for installation and maint ...

servicing a single subscriber; e.g., a dwelling or office. ONU devices supply

and possibly other services to the users, either directly (by bridging) or through a gateway device such as a

residential gateway A residential gateway is a small consumer-grade gateway which bridges network access between connected local area network (LAN) hosts to a wide area network (WAN) (such as the Internet) via a modem, or directly connects to a WAN (as in EttH), wh ...

firewall Firewall may refer to: * Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts * Firewall (construction), a barrier inside a building, designed to limit the spr ...

, and/or router, POTS,

CATV Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...

signals to buildings wired for RF video, and some may even be compatible with the emerging G.hn home networking standard. The ONU receives the downstream data from the Internet or private networks, and also uses time slots allocated by the OLT to send the upstream traffic in burst-mode. TDMA time slots prevent collisions with upstream traffic from other users sharing the same physical PON. Fibre-to-the-cell site is another emerging application, but has extra synchronisation requirements. A specialised Cellular Backhaul Unit (CBU) can provide PON access for cellular networks.

OLT and access nodes

The OLT ( Optical Line Terminal) connects the PON to aggregated backhaul uplinks, allocates time slots for ONUs and ONTs to transmit upstream data, and transmits shared downstream data in broadcast-mode over the PON to users. Since 10GPON is designed to coexist with GPON devices, migration to a 10GPON capability could be done by upgrading the OLT and then migrating individual ONUs as needed. Normally the OLT is on a card that slots into a chassis at the Central Office (CO), which uses special uplink cards for

backhaul to the telecommunications provider's network and internet. Uplink cards on access equipment will likely use multiple Ethernet interfaces, although it remains to be seen what uplink speeds manufacturers will offer to support 10GPON access. Locating OLTs in

outside plant In telecommunication, the term outside plant has the following meanings: *In civilian telecommunications, outside plant refers to all of the physical cabling and supporting infrastructure (such as conduit, cabinets, tower or poles), and any associ ...

cabinets may be an option for reach extension as a way to minimise the number of central offices covering low population density areas. ITU and IEEE are planning for convergence of their specifications at the physical layer in 10G that would allow for the shared chips, optics and hardware platforms, thus driving cost reductions for hardware manufacturers.

Optical distribution network

PON Optical Distribution Networks use single-mode optical fibre in the

optical splitter A beam splitter or ''beamsplitter'' is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding wide ...

s and optical distribution frames, duplexed so that both upstream and downstream share the same fibre on separate wavelengths. 10G-PON is no exception with similar reach to previous standards but supporting a higher split ratio of 128 users per PON, or more using reach extenders/amplifiers.

Optical splitter A beam splitter or ''beamsplitter'' is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding wide ...

s creating a point to multipoint topology are also the same technology as those used by other PON systems. This means any PON network should be upgradable by changing the ONT and OLT terminals at each end, with no change to the fibre itself unless different connectors are chosen. "An Optical Distribution Network (ODN) being installed today will likely need to support four or more generations of PON over its expected 30 – 40 year life... The fibre should enable maximum flexibility to support any potential new PON technology, be protected with proven, reliable cabling making it easy to install and reliable, and be joined by advanced, low labor and low loss connectivity. The cost of the ODN materials (fibre, cable, and connectivity) at only about 8% comprises a surprisingly small portion of the total network cost." In an effort to extend the reach with support for 128 splits, the standard supports a range of optical budgets from 29 dB to 31 dB. A draft update to the standard is expected to further extend this to 33 dB and 35 dB budget classifications. A PON with a 35 dB optical budget could span 25 km or more and be shared/split among 128 subscribers. Some ONTs can receive a broad range of optical spectrum from 1480 nm to 1580 nm, so making the 10G-PON downstream signal visible to G-PON receivers. As a result, ONTs must block the unwanted downstream signals with a wavelength blocking filter (WBF), a small passive optical device.

Field trials

* In October 2010, Portugal Telecom reported a successful field trial of 10G-PON, transmitting 3D-TV content using XG-PON1 capabilities.
Verizon
also successfully completed a field trial of the pre-standard XG-PON2 (synchronous 10G-PON) capable of delivering a 10 Gbit/s broadband connection both downstream and upstream. In October 2010, at a Verizon customer's business in Taunton, Mass., the XG-PON2 trial used the same optical fibre that provides that business with its existing FiOS network connection and services. * BT in the UK is providing a trial 10-Gbit/s broadband service to a business customer in Cornwall using XGPON technology, it announced on 23rd Nov 2012. * Chorus in New Zealand is providing a trial 10-Gbit/s broadband service to customers using XGS-PON technology. It was announced on 18th Nov 2019. * OpenFiber (wholesale-only FTTH carrier in Italy) has successfully trialled a 10Gbit service with coexisting GPON on the same fiber, using XGS-PON technology from ZTE, on March 14, 2019 in collaboration with ISP Fibra.city. **Announced the commercial availability on its OpenStream product (bitstream access) on March 26, 2021. *Telecom Italia is starting a trial on three exchanges in Italy using XGS-PON equipment from Nokia, both to its retail customers and to its wholesale clients.

Home broadband service providers

* - TIM * - Smart Infra * - DELTA * - KPN * - So-net * - PCCW-HKT * - SingTel, M1 * - Swisscom, Salt Fiber, Sunrise, Quickline * - Inea * - Chorus * - Orion Telekom * - Antik Telecom * - Digi Spain * - Digi Romania * - SLT * - toob, G.Network * - Telemach * - AT&T * - Cox Communications * - Frontier Communications * - Sonic * - Ziply Fiber * - Summit Broadband * - Bell

Commercial broadband service providers

* - Orange Spain * - M1 * - Sfr * - Monaco Telecom * - Netalis (France) * - Chorus * - Orion Telekom * - Antik Telecom * - Telemach * -

Converge ICT Converge ICT Solutions Inc., commonly referred to as Converge (also known as ComClark in Pampanga), is a telecommunication service provider in the Philippines. It operates fiber optic broadband networks, Internet Protocol television (marketed as ...

https://www.yugatech.com/news/converge-gets-its-first-live-customer-of-10gpon-technology-service/

References

External links

FTTH Council Europe - FTTH Business Guide
(Updated 24 Aug 2011)
FTTH Council Europe - FTTH Handbook, Fourth Edition
(Updated 24 Aug 2011)
ITU-T GPON Summary

Benjamin Reboul, FTTH Council APAC, “A Global Overview of FTTH”, FTTH Council APAC Annual Conference, May 25 2010
(Retrieved 08 Nov 2010) * http://conference.vde.com/ecoc-2009/programs/documents/sp_stefandahlfort_ng%20access.pdf * https://web.archive.org/web/20110708133401/http://www.chaffeefiberoptics.com/nwsltr/Municipal%20and%20Utlity%20Guidebook.pdf
Technologies and applications of Passive Optical Networks (PON)- Yukio Nakano

A Chip Off the Old Block: System Requirements, Challenges, and Standards for Next-Generation PON
{{DEFAULTSORT:10g-Pon Broadband Fiber-optic communications Network architecture ITU-T recommendations ITU-T G Series Recommendations