Patent ID: 7551854

Claim:
An optical transmission system having a central station connected to an IP network, a plurality of user units, each having an IP phone, and an optical transmission line coupled between the central station and the plurality of user units, the system comprising: a plurality of optical connectors, each optical connector disposed at one of a plurality of user connection ports of the optical transmission line to which one of the plurality of user units is connected respectively, each optical connector having an identification medium for storing unique port identification (ID) information; a plurality of optical network units, each optical network unit (ONU) disposed in one of the plurality of user units to connect to a respective one of the optical connectors, and having a reader to read out the port ID information stored in the identification medium of the optical connector, to transmit a first connection request signal including destination information and the port ID information to the central station, when a respective IP phone originates a predetermined call, and to transmit a second connection request signal including the destination information and not including the port ID information to the central station, when the respective IP phone originates a call other than the predetermined call; a port control information file to store relations between the port ID information stored in the identification mediums of the optical connectors attached to the respective user connection ports and corresponding locations of each of the optical connectors; and a repeater disposed in the central station to detect, when the user unit transmits the first connection request signal for the predetermined call, a location of the optical connector to which the IP phone originating the predetermined call is connected by checking the port ID information against the port control information file, and to send information indicating the detected location and the destination information to the IP network.