Shanghai Institute of Applied Physics, Chinese Academy of Sciences
In Ethernet Passive Optical Networks (EPONs) with offline Dynamic Bandwidth Allocation (DBA) framework, the Optical Line Terminal (OLT) will first collect bandwidth requests from all Optical Network Units (ONUs), and then make bandwidth allocation and scheduling decisions for the shared upstream channel. Due to varying Round-Trip Time (RTT) and grant window sizes, the transmission order of ONUs will greatly affect the mean packet delay. In this paper, the authors address this grant scheduling problem aiming at minimizing the mean packet delay. They prove several theorems which could determine the ONU to transmit first which will minimize the mean packet delay.