Delay-aware sleep control of optical network unit in EPONs using disturbance observer

抄録

Recently, quality-of-service (QoS)-aware cyclic sleep controllers for optical network units (ONUs) have been proposed to guarantee the QoS and energy efficiency in passive optical networks (PONs). Proportional-integral-derivative (PID)-based cyclic sleep controllers can maintain the average downstream queueing delay in an optical line terminal (OLT) at a constant level. However, conventional PID-based controllers generate errors between a target queueing delay and an actual delay because of the nonlinear characteristics of the cyclic sleep mechanism. This letter proposes a feedback controller with a disturbance observer (DOB) that includes a linearized cyclic sleep model to improve the QoS in terms of the average downstream queueing delay. Simulations confirm that the proposed DOB-based controller can reduce errors effectively compared with a PID-based controller.