Schedule 4 to the Broadcasting Services Act 1992 sets out arrangements for the conversion, over time, of the transmission of commercial and national television broadcasting services from analog mode to digital mode. Two schemes were formulated: the Commercial Television Conversion Scheme 1999 which commenced on 9 June 1999 and the National Television Conversion Scheme 1999 which commenced on 2 February 2000.
Under both schemes, the ABA, and subsequently the ACMA, made a national and a commercial digital channel plan for each area. The digital channel plans (DCPs) determine which channels are to be allotted to each area, the assignment of channels to each broadcaster and the technical characteristics of those channels. The Authority's objective in preparing the DCPs is to enable a broadcaster to plan its digital transmission coverage to match its analog coverage.