A novel AWG-based WDM-PON architecture with full protection capability

The higher bandwidth utilization of wavelength-division-multiplexing passive optical networks (WDM-PONs) can be problematic if the link failure is not repaired in a timely manner since major data losses may occur in the event of link failure. Therefore, developing robust WDM-PON architectures with an effective protection capability is an essential task when designing optical access networks. Although the literature contains many proposals for WDM-PON protection schemes, the majority of these schemes protect either the feeder fibers or the distribution fibers, but not both. By exploiting the cyclic properties of the AWG and establishing appropriate interconnections between matched pairs of ONUs such that one ONU in the pair can use the distribution fiber assigned to its partner for backup purposes, the proposed scheme can protect both the feeder fibers and the distribution fibers through the designated protection streams in feeder fiber 3. Additionally, five operational modes of the proposed scheme are detailed with the proposed wavelength assignment scheme, the operational sequence, and the operation flow chart of decision circuit in the ONU/OLT. The analytical results have shown that the proposed scheme not only provides a full protection capability for WDM-PON networks, but also has a lower unavailability, a lower construction cost, and a reduced wavelength requirement than existing representative protection schemes. Finally, an analysis of the power budget and the recovery time has confirmed the practical feasibility of the proposed scheme.