EPON and GPON

Ethernet PON (EPON) and gigabit PON (GPON) are main PON technologies. The EPON standard was defined by the IEEE 802.3ah working group, and the GPON standard was defined by the International Telecommunication Union (ITU) and the Full Service Access Networks (FSAN).

The Ethernet in the First Mile (EFM) task force, founded in November 2000, brought forward the EPON concept and described it in IEEE 802.3ah. EPON integrates the Ethernet and PON technologies and provides 1.25 Gbit/s symmetric transmission rate on upstream and downstream links. An EPON network is a point-to-multipoint gigabit optical access system. EPON technology complies with IEEE Ethernet standards and is a good choice for migration to the all-IP network.

ITU and FSAN developed and standardized GPON technology. This technology uses the Generic Framing Procedure (GFP) defined by ITU-T to encapsulate Ethernet, time division multiplexing (TDM), and Asynchronous Transfer Mode (ATM) packets at Layer 2. GPON technology provides the downstream transmission rate of 1.25 Gbit/s or 2.5 Gbit/s, and the upstream transmission rate of 155 Mbit/s, 622 Mbit/s, 1.25 Gbit/s, or 2.5 Gbit/s, and has strong OAM functions. GPON technology provides a higher transmission rate and supports more services than EPON technology, but it is more complicated and expensive and is not as mature as EPON technology.

PON is becoming the mainstream bearer technology for the next generation access network because of its advantages of long transmission distance, high QoS guarantee, and high bandwidth.