OPTI-6G Preliminary U/D Converter Integration Test by RunEL – Demo video

OPTI-6G has released a new demonstration video detailing the Preliminary Up/Down Converter Integration Test carried out by RunEL. In the video, Dr Zion Hadad, RunEL CEO, presents the outcomes of the first integration and testing phase of the U/D converters within the OPTI-6G experimental setup.

The test is part of the OPTI-6G roadmap towards ultra-accurate UE localisation and cell-free networking over an Optical Air Interface. Following development and initial validation at Oledcomm, the U/D converters were delivered to RunEL in November 2025 and integrated into a 3.5 GHz B5G private network environment. The setup includes RF-to-light transducers, VCSEL-based optical links and commercial UE terminals, enabling realistic downlink and uplink evaluations.

The video walks through preliminary measurements performed at RunEL, including throughput comparisons with and without the U/D converters, as well as latency and jitter assessments. Tests were conducted over bandwidths up to 75–100 MHz, confirming stable operation while also identifying unwanted signal components that can degrade performance. As explained in the presentation, these effects can be mitigated using advanced filtering or I/Q mixing techniques, which are not required for OPTI-6G’s core research objectives but would be relevant for future commercial OWC deployments.

This preliminary integration test marks an important milestone before the delivery of the validated converters to Brunel University, where full optical–wireless integration with the 5G network and final localisation and cell-free trials will take place. The demo provides a clear, practical view of how optical and RF technologies are being combined within OPTI-6G to support future 6G systems.