(Optical Line Termination) provides the network-side interface of the Optical Access Network (OAN), and is connected to one or more Optical Network Units (ONUs). ONT

The Optical Line Terminal is the PON controller card or unit it is located at the central office. The terminal at the subscriber's end of the network is the ONT or optical network terminal. Several OLTs may be located in a single chassis. The laser at the OLT is frequently a DFB (distributed-feedback laser) transmitting at 1490nm or 1550nm and is always on. Signals from the OLT tell the ONTs when to send upstream traffic to it.

Abbreviation for optical line termination. Optical network elements that terminate a line signal.

A switch that sends traffic downstream to subscribers and that also handles the upstream traffic.

OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), was the first land mobile telephone network in Norway. It was established December 1 1966, and continued until it was obsoleted by NMT in 1990. In 1981, there were 30,000 mobile subscribers, which at the time made this network the largest in the world.