Patent ID: 7653084

Claim:
A bandwidth allocation method for guaranteeing a Quality of Service (QoS) in an Ethernet Passive Optical Access Network (EPON) comprising: classifying up-stream data received from a plurality of user terminals to be transmitted from a plurality of Optical Network Units (ONUs) of the EPON to an Optical Line Terminal (OLT) into a plurality of classes according to predetermined data priority information, and requesting bandwidths required for individual classes from the OLT; allowing the OLT to perform a bandwidth distribution process according to bandwidth requirement quantities of individual classes using weights pre-assigned to individual classes; and allowing the OLT to distribute a residual bandwidth acquired after the bandwidth distribution process is performed from among an available total up-stream bandwidth to the ONUs, wherein the up-stream data is received from each of the plurality of user terminals is classified into the plurality of classes, and wherein the allowing the OLT to distribute the residual bandwidth acquired after the bandwidth distribution process is performed from among the available total up-stream bandwidth to the ONUs includes the step of: if the residual bandwidth BW REM is less than bandwidths requested by the ONUs, excluding a low-priority ONU according to a predetermined ONU priority until a value BW REM N acquired when the residual bandwidth BW REM is divided by a predetermined number N equal to the number of ONUs is higher than a minimum Ethernet frame transmission time, and allocating an up-stream bandwidth larger than a bandwidth corresponding to the minimum Ethernet frame transmission time to high-priority ONUs.