An Efficient USR Eliminating Mechanism on EPON

OLT can correctly predict the upper edge and down edge of the packet that reached by DBA GRANT by reshaping all packets arriving and buffed in queues in a cycle during ONU idle time. By adjusting the last GRANT to reach the nearest edge of the packet, all USRs are not only eliminated, but also the whole USR size is reduced, the average cycle length and the average GRANT are kept unchanged, the available bandwidth increases and QoS level is improved. The simulation results verify its merits well.