Digital Radio Mondiale (DRM), the digital broadcasting system operating in the bands below 30 MHz, was officially launched in June 2003 and a large number of broadcasts are now on the air. Broadcasters can gain the most benefit from the improved audio quality and flexibility provided by DRM over traditional AM broadcasts by taking care over the design of the transmission infrastructure used to distribute their signals to transmitting stations. Many of these issues have been addressed by the Multiplex Distribution Interface (MDI) protocol, developed by a sub-group within DRM. This paper explains the advantages of using MDI over traditional methods of programme distribution and uses the transmission infrastructure developed for the BBC's DRM transmissions as an example.