Sleep Mode Mechanism with Improved Upstream Performance for Passive Optical Networks

With the proliferation of advanced and interactive services together with high demand for premium quality of experience, the upstream traffic grows faster than the downstream traffic. Therefore we propose a new power-saving mechanism called the sleep-transmit mode, which enables optical network units (ONUs) to transmit upstream data during sleep periods without turning on the receiver to conserve energy and improve the upstream transmission delay. These advantages are achieved through pre-allocating bandwidth before individual ONU enters the sleep state. The analytical model of the proposed power-saving mechanism shows that (1) the power consumption of an ONU can be reduced by 49% using the proposed sleep-transmit mode (STM) mechanism, compared to the ONU with standard sleep mode, and (2) the estimated upstream delay due to sleep-mode is also reduced by up to 10-fold compared to that of conventional XGPON cyclic sleep mode mechanism.