The H2020 European Project Beyond 5G – OPtical nEtwork coNtinuum (B5G-OPEN) where CTTC participates as WP leader in control and orchestration, targets the design, prototyping and demonstration of a novel end-to-end integrated packet-optical transport architecture based on MultiBand (MB) optical transmission and switching networks with pluggable interfaces. MB expands the available capacity of optical fibres, by enabling transmission within S, E, and O bands, in addition to commercial C and/or C+L bands, which translates into a potential 10x capacity increase and low-latency for services beyond 5G. B5G-OPEN developments include SONIC based packet/optical devices with pluggable transceivers and a Control Plane for Multiband optical networks. B5G-OPEN focuses on the innovative technologies enabling the mid/long term evolution towards beyond 5G scenario from the perspective of the end-to-end optical transport infrastructure. The consortium includes 3 major operators (Telefonica, BT and TIM), optical system vendors and integrators, research institutions and universities and SMEs. B5Open relates to the 5G-Acceleration and OpenNet themes of MWC23.