 The BBC undertook a trial of the digital radio <unk> ( DRM ) technology , which allowed them to explore digital radio using medium @-@ wave frequencies . The trial broadcast BBC Radio Devon using the new technology in the Plymouth area from April 2007 and closed down on 31 October 2008 . In May 2009 , the BBC released a report on the trial in Devon . The report gave a number of conclusions about DRM from the trial : 
