Although called 4Digital and led by Channel 4, the second national digital audio broadcasting network had other media firms involved too, so in theory C4's previously reported decision to pull out of DAB completely doesn't have to mean that second national DAB service won't go live.
Though, it probably won't. Talk is that the other companies involved, BSkyB, Bauer, UTV, UBC Media and Carphone Warehouse, all of whom were going to launch a new station to appear on the network, are all getting cold feet about the whole venture now that majority shareholder Channel 4 is out of the picture.
Whether the probable collapse of the second national DAB network will have any impact on other DAB services remains to be seen - with the exception of the BBC, many radio firms are now shying away from DAB-only services.