Survivable architectures of time and wavelength division multiplexed networks: A comparison of reliability, cost, and energy efficiency

Current solutions for rapid fault detection and subsequent restoration of services in conventional PONs rely on the loss of signal (LOS) of upstream transmissions to trigger protection switching. For next-generation time and wavelength division multiplexed PON (TWDM-PONs), these solutions are unsuitable as TWDM-PONs will potentially use sleep/doze mode ONUs. Using existing solutions based on LOS would mean that the loss of upstream transmission from a sleeping or dozing ONU could erroneously trigger protection switching. Three survivable architectures that are compliant with TWDM-PON specifications will be discussed in this talk. They combine rapid detection and protection switching against multipoint failure, and most importantly do not rely on upstream transmissions for LOS activation. Survivability analyses and evaluations on the additional costs and energy incurred to achieve survivability, are performed and compared to the unprotected architecture.