australia was one of the first countries to undertake tests of digital radio. extensive tests were undertaken of the dab system at 1.5 ghz in the early 1990s. the australian policy framework slowly evolved with a number of published studies and policy analyses. there was recognition that only capital city markets would be economically viable for the new medium while digital receiver penetration slowly ramped up. these services commenced in july 2009 using channels within the band iii tv band. a significant deployment of digital on-channel repeaters has been effected in recent years to in-fill coverage gaps both within and at the periphery of their coverage areas.