Passive Optical Network, PON
Passive Optical Network (PON) mainly uses passive optical power splitters (couplers) to send information to users. Since the optical power divider is used to reduce the power, it is more suitable for short-distance use.
PON (Passive Optical Network) means that ODN (Optical Distribution Network) does not contain any electronic devices and electronic power supplies. ODN is all composed of passive devices such as optical splitters (Splitter) and does not require expensive active electronic equipment. . A passive optical network includes an optical line terminal (OLT) installed in the central control station, and a group of matching optical network units (ONUs) installed in the user’s premises. The optical distribution network (ODN) between the OLT and the ONU contains optical fibers and passive optical splitters or couplers.
The development of PON technology
APON (ATM PON)
It was proposed in 1995. In 1996, 13 large network operators and their main equipment suppliers formed the FSAN (Full Service Access Network) alliance, 155Mb/s PON system technical specification, ATM transmission protocol, ITU-T G.983 Series standards
BPON (Broadband PON)
In 2001, the APON standard was later strengthened to support a transmission rate of 622Mb/s. At the same time, dynamic bandwidth allocation, protection and other functions were added to provide services such as Ethernet access, video transmission, and high-speed leased lines. Broadband PON
GPON (Gigabit PON)
The FSAN Alliance is conducting research on PON standards with speeds above 1Gb/s, hoping to propose a solution that, in addition to being able to run at higher speeds, is more efficient than other PONs in terms of multi-service, OAM&P, and scalability. high. This research led to the emergence of Gigabit PON (GPON). In January 2003, ITU-T approved the establishment of GPON standards G.984.1, G.984.2 and G.984.3
EPON (Ethernet PON)
It is a new type of optical fiber access network technology, which uses point-to-multipoint structure, passive optical fiber transmission, and provides multiple services on Ethernet. It uses PON technology at the physical layer, Ethernet protocol at the link layer, and uses the PON topology to achieve Ethernet access. Therefore, it combines the advantages of PON technology and Ethernet technology: low cost; high bandwidth; strong scalability, flexible and fast service reorganization; compatibility with existing Ethernet; convenient management, etc.