Abstract: A digital interface between analogue RF hardware and digital processing hardware which (a) defines how the analogue RF hardware and digital processing hardware send and receive digital data to one another and (b) is open in order to decouple the design of the analogue RF hardware from the design of the digital processing hardware. The adoption of such an interface will facilitate the uptake of software defined radio (SDR), both as a design-time and run-time technology, as it enables the production of analogue/RF components independently from the digital domain hardware and software.