Node design in Self-Managed Sustainable High-Capacity Optical Networks (SEASON)

The goal of the SEASON project [1] is to design and validate a transport network infrastructure able to support beyond 5G and new emerging services, relying on the joint usage of Multi-Band and SDM, spanning the access, aggregation, and metro/long-haul segments, supporting the requirements for x-haul, further integrating the packet/optical and computing layers. The targeted SEASON architecture considers these innovations in addressing sliceable Bandwidth Variable Transceivers (S-BVTs) enabling Point-to-MultiPoint (P2MP) along with the integration of (coherent) pluggable optical modules on open packet/optical white boxes (open devices with hardware and software - referred to as the Network Operating System, - decoupling and providing open control and management interfaces), smart Network Interface Cards (NICs) or the latest generation Data Processing Units (DPU). In this paper, a multi-granular MBoverSDM modular and flexible Optical Switch architecture is presented, that can simplify the node design and enhance switching capabilities in SEASON high capacity packet transport network. Figure 1 displays the node architecture integrated with the RAN, which will be exploited to coordinate user-cell association and latency enforcement in the optical access based on achievable end-to-end latency. Such a node design is capable of dynamically route and add/drop traffic while potentially increasing the switching capacity in a flexible manner. Each layer can include different technology options such as WSSs and/or passive filters for band/spatial multiplexing and demultiplexing, which will offer different levels of flexibility. In the below figure, we depict a 3rd order nodal degree, covering three directions (North, East, and West), in each of which three pairs of optical fibers and three spectral bands (S, C, and L) per fiber are rolled out. This design enables switching at the spectral band level as well as at the wavelength level, facilitated by individual-band WSSs. The node design integrates all essential optical components, including band filters (BF), amplifiers, spatial Optical Cross-Connector (S-OXC) switches, WSSs, and A/D modules. These components are interconnected to establish a modular colorless-directionless (CD) MBoverSDM node architecture, but a colorless-directionless-contentionless (CDC) architecture could be easily implemented by just removing the 1x20 WSS connected to the contentionless NxN WSS or substituting it with additional contentionless MxN WSS.