 Mitola objected to Blust's term, but finally accepted it as a pragmatic pathway towards the ideal software radio.Although the concept was first implemented with an IF ADC in the early 1990s, software-defined radios have their origins in the U.S. and European defense sectors of the late 1970s(for example, Walter Tuttlebee described a VLF radio that used an ADC and an 8085 microprocessor).about a year after the First International Conference in Brussels.