Patent ID: 8331400
Filing Date: 2012-12-11
Classification: H04Q

Abstract:
1. A passive optical network (PON) system comprising: a plurality of optical network units (ONUs) accommodating a user terminal, an optical line unit (OLT) connected to a wide area network, and a passive optical network (PON) connected between the ONUs and the OLT; the OLT transferring a unicast downstream frame received from a communication node equipment in the wide area network to the plurality of ONUs via the PON; and the plurality of ONUs transferring the unicast downstream frame to the user terminal, wherein the unicast downstream frame includes a Layer 2 header and an IP packet, wherein the OLT has a frame analyzing unit that removes at least a part of Layer 2 header information from the Layer 2 header of the unicast downstream frame received from the communication node equipment and outputs the unicast downstream frame whose length is shortened, and a frame generating unit that generates a PON frame by adding a PONspecific header to the unicast downstream frame outputted from the frame analyzing unit, and wherein each of the ONUs has a table that corresponds IP addresses with MAC addresses and a downstream frame processing unit that extracts an IP address of the unicast downstream frame from the PON frame received via the PON, and adds Layer 2 header information generated in each ONU based on the table into the unicast downstream frame from which the at least part of the Layer 2 header information has been removed by the OLT, wherein a downstream frame which the OLT received from the communication node equipment contains an Ethernet header as a Layer 2 header, wherein the frame analyzing unit of the OLT removes at least a destination MAC address, a source MAC address, and a protocol type from the Layer 2 header information of the downstream frame, and wherein the downstream frame processing unit of each ONU adds at least a destination MAC address, a source MAC address, and a protocol type generated therein as the Layer 2 header information to the downstream frame extracted from the PON frame received from the OLT via the PON.