What is GPON?
GPON (Gigabit-Capable PON) technology is the latest generation of broadband passive optical integrated access standard based on the ITU-TG.984.x standard. It has many advantages such as high bandwidth, high efficiency, large coverage, and rich user interfaces. Most operators regard it as an ideal technology to realize broadband and comprehensive transformation of access network services.
GPON was first proposed by the FSAN organization in September 2002. On this basis, ITU-T completed the formulation of ITU-T G.984.1 and G.984.2 in March 2003, and completed G.984.1 and G.984.2 in February and June 2004. 984.3 standardization. Thus finally formed the standard family of GPON.
The basic structure of the equipment based on GPON technology is similar to that of the existing PON. It is also composed of OLT (optical line terminal) at the central office and ONT/ONU (optical network terminal or called optical network unit) at the user side. ODN (Optical Distribution Network) composed of SM fiber and passive splitter (Splitter) and a network management system.
For other PON standards, the GPON standard provides unprecedented high bandwidth, with a downstream rate of up to 2.5Gbit/s, and its asymmetric characteristics can better adapt to the broadband data service market. It provides full service guarantee of QoS, and carries ATM cells and (or) GEM frames at the same time. It has a good ability to provide service levels, support QoS guarantee and full service access. When carrying GEM frames, TDM services can be mapped to GEM frames, and standard 8kHz (125μs) frames can directly support TDM services. As a telecommunication-level technical standard, GPON also specifies the protection mechanism and complete OAM functions at the access network level.
In the GPON standard, the types of services that need to be supported include data services (Ethernet services, including IP services and MPEG video streams), PSTN services (POTS, ISDN services), dedicated lines (T1, E1, DS3, E3, and ATM services). ) And video services (digital video). Multi-services in GPON are mapped to ATM cells or GEM frames for transmission, which can provide corresponding QoS guarantees for various service types.