Passive Optical Network

A passive optical network (PON) is a point-to-multipoint, fiber to the premises network architecture in which unpowered optical splitters utilizing Brewster's angle principles are used to enable a single optical fiber to serve multiple premises, typically 32-128. A PON consists of an optical line terminal (OLT) at the service provider's central office and a number of optical network units (ONUs) near end users. A PON configuration reduces the amount of fiber and central office equipment required compared with point to point architectures...more...
Gigabit Passive Optical Network (GPON) is standardized by the ITU in its G.984 series. It is used around the world for FTTH and in the US is thought to be the successor to BPON. 10G GPON is covered in another article.
The ITU GPON standard allows up to 2.488Gbps symmetric transmission, but almost all GPON systems are 2.488Gbps down/1.244Gbps up. Downstream from the OLT to the ONTs is broadcast with an ONT grabbing only traffic addressed to it. Upstream is Time Division Multiple Access (TDMA) with each ONT transmitting in turn....more