A Centrally-Controlled Intelligent Protection Switching Scheme for WDM-PONs
Several protection schemes have been proposed for Wavelength Division Multiplexed Passive Optical Networks (WDMPONs). However these schemes only work under the assumption that all the Optical Network Units (ONUs) and the Optical Light Terminal (OLT) continuously transmit optical signals. In practice, some ONUs may be in sleep mode to save power consumption or may be shut down whenever users are offline. Under such scenarios, the existing schemes would not work. To deal with more practical operation scenarios, the authors propose a centrally controlled intelligent protection switching scheme for survivable WDM-PONs.