Energy-Efficient and Survivable Optical Access Network Based on Multilayer-Ring Structure

An energy-efficient and survivable optical access network structure is proposed and investigated. Based on a structure model of multilayer-ring, the access network is divided into four layers and modules on a same layer are interconnected as a ring. Therefore, multiple paths are available for optical network units to access an optical line terminal, which not only provides convenience in traffic aggregation, but also guarantees the survivability of network. With this structure, quantities of standby modules are reduced to decrease both capital cost and power cost. Large part of power can also be saved by turning off idle modules through traffic aggregation. Moreover, by controlling the optical switches deployed in remote node, elastic reach access is realized as well since amplification is optional on transmission links. Theoretical and numerical analyses indicate that the scheme shows great advantages on power saving, network survivability, as well as the system flexibility, and its energy efficiency performance can be further improved by operating in conjunction with energy-efficient resource scheduling scheme. It provides a potential structure for next generation optical access network.