Patent ID: 8315523

Claim:
A communication system comprising a single physical PON (Passive Optical Network), said physical PON comprising a subscriber's terminal unit having a LAN (Local Area Network) port and a PON port, a station's terminal equipment having a plurality of LAN ports and a PON port, and an optical fiber which connects between the PON ports of the subscriber's terminal unit and the station's terminal equipment, wherein: said physical PON is used as a plurality of virtual PONs which are obtained by virtually dividing said physical PON; each of the station's terminal equipment and the subscriber's terminal unit has a VPID table which holds a correspondence between VPIDs (Virtual PON Identifiers) for identifying the virtual PONs and the LAN ports or the subscriber's terminal unit; a group of the port and the unit having the identical VPID being recognized as a single PON domain; and the VPID for identifying the PON domain being embedded in a Preamble/SFD (Start Frame Delimiter) region of a LAN frame, the VPIDs being used in logically dividing said physical PON to obtain the virtual PONs.