Dedicated segment protection schemes using digital subcarrier in optical networks: A power consumption comparison

This paper presents a comparative study of the network-wide electric power that is required to operate Digital Subcarrier Optical Networks (DSONs) when dedicated segment protection schemes are used. Traffic protection from unexpected network element failures is achieved directly in the optical layer by provisioning a stand-by (secondary) lightpath for every working lightpath required in the network to support the offered traffic. The DSON solution is compared against the currently widely used TDM-based optical transport network (OTN) in terms of both protection scheme options and electric power requirements. The advantage of adopting DSONs is threefold: (1) the inherent digital signal processing capability that is required to implement digital subcarrier channel multiplexing, (2) the ability to switch off the inactive sub-wavelength channels (subcarriers) and (3) the ability to provision protection channels in stand-by mode using low rate signalling channels. Simulation experiments are discussed and used to quantify the potential DSON power savings (up to 40%) when compared to a commercially available OTN based solution.