Digital Subcarrier Multiplexing: Enabling Software-Configurable Optical Networks

The various topologies, traffic patterns and cost targets of optical networks have prevented the deployment of end-to-end solutions across multi-domains, and the optimization of the network as a whole. The consequent limitations in flexibility, scalability, and adaptability of optical networks will become increasingly important with new applications, such as 5G/6G. Coherent transceivers based on digital subcarrier multiplexing (DSCM) are proposed to address these current constraints. In particular, DSCM allows (i) the design of high-capacity point-to-point (P2P) and -multipoint (P2MP) optical networks; (ii) simplified aggregation with passive optics; and (iii) connections between low- and high-speed transceivers. Furthermore, DSCM-based networks reduce the number of opto-electro-opto stages, halve the number of bookended transceivers, and provide a better match for existing hub-and-spoke (H&S) traffic patterns in fast-growing and dynamic access/metro segments. A DSCM-based transceiver will pave the way for the deployment of next-generation flexible, adaptable, and scalable software-configurable optical networks. Key steps and elements to realize this solution are laid out, and promising applications outlined. The first real-time experimental results of coherent P2MP transceivers are presented.

Automated summary

The deployment of end-to-end solutions across multi-domains in optical networks has been hindered by various factors. Coherent transceivers based on digital subcarrier multiplexing (DSCM) are proposed to address these issues and improve the flexibility, scalability, and adaptability of optical networks. DSCM allows for the design of high-capacity point-to-point and point-to-multipoint optical networks, simplified aggregation with passive optics, and connections between low- and high-speed transceivers. Furthermore, DSCM-based networks reduce the number of opto-electro-opto stages, halve the number of bookended transceivers, and better suit existing traffic patterns in fast-growing and dynamic access/metro segments. Experimental results of coherent point-to-multipoint transceivers are presented, highlighting the potential of DSCM-based solutions.