Digital subcarrier optical networks (DSONs)

This paper describes an energy efficient and data rate flexible network transport solution to achieve sub-wavelength circuit provisioning between edge node pairs. Sub-wavelength circuits are obtained by concatenating spectrally efficient digital subcarrier channels along the network path, with each subcarrier frequency carrying only a fraction of the wavelength bandwidth. By reserving one or more such subcarrier frequencies along a path connecting two edge nodes, a dedicated end-to-end sub-wavelength circuit is provisioned. At intermediate nodes, incoming frequencies are switched to outgoing frequencies via a specially designed frequency selective switch or cross-connect, described in a companion paper [7]. The power consumption required to switch subcarrier frequencies across the network is estimated to be a fraction of the power dissipated by currently available transport solutions, e.g., optical transport network (OTN) and multiprotocol label switching transport profile (MPLS-TP).