High-capacity WDM regional access networks based on a hierarchical star-ring-bus architecture

We propose a novel hybrid star-ring-bus architecture (SRBA) for broadband wavelength-division multiplexed (WDM) regional access networks. A delta-star network on the top level acts as high-capacity infrastructure for the communication between the central office (CO) and optical network units (ONUs), whose weakness in reliability is overcome by the self-healing function of the concatenated ring network on the lower level. The ring network is divided into several delta regions, where the traffic load inside each region is unified to minimize the backup resources required in the network. On the bottom level, considerable bus subnets are constructed to serve end users. Furthermore, the bit-error-rate (BER) performance of downstream signal traffic over the proposed access network is analyzed as well.