Patent ID: 8457495
Filing Date: 2013-06-04
Classification: H04J

Abstract:
1. A network system comprising: a first OLT (Optical Line Terminal), a second OLT, a first ONU (Optical Network Unit), and a second ONU, wherein the first OLT and the second OLT are connected to the first ONU and the second ONU through an optical fiber shared by the first OLT and the second OLT such that data is transmitted between the first OLT and the first ONU and between the second OLT and the second ONU, wherein time division multiplexing is performed during data transmission between the first OLT and the first ONU and between the second OLT and the second ONU, the first OLT and the second OLT mutually share uplink communication band allocation information so that each of the first and second ONUs transmits an uplink frame, the first OLT allocates a first uplink communication band to the first ONU which is different from a second uplink communication band that is allocated to the second ONU, and allocates the second uplink communication band to the second ONU, wherein the first and second OLTs are connected to a DBA control unit that allocates the uplink communication band to the first OLT and the second OLT, and the DBA control unit notifies the uplink communication band information which is allocated to the first OLT and the second OLT, and wherein the DBA control unit includes a band request management table that stores an uplink communication request band notified from the first OLT and the second OLT and priority of the uplink band allocation between the first OLT and the second OLT, and the DBA control unit allocates the uplink band based on the priority of the uplink band.