  The ever-growing number of wireless communication devices and technologies
demands spectrum-sharing techniques. Effective coexistence management is
crucial to avoid harmful interference, especially with critical systems like
nautical and aerial radars in which incumbent radios operate mission-critical
communication links. In this demo, we showcase a framework that leverages
Colosseum, the world's largest wireless network emulator with
hardware-in-the-loop, as a playground to study commercial radar waveforms
coexisting with a cellular network in CBRS band in complex environments. We
create an ad-hoc high-fidelity spectrum-sharing scenario for this purpose. We
deploy a cellular network to collect IQ samples with the aim of training an ML
agent that runs at the base station. The agent has the goal of detecting
incumbent radar transmissions and vacating the cellular bandwidth to avoid
interfering with the radar operations. Our experiment results show an average
detection accuracy of 88%, with an average detection time of 137 ms.
