They've had to switch their over the air broadcasting to all digital broadcasting.

After Feb 17, 2009, all analog television broadcasting will be discontinued and will become digital.

Digital Video Broadcasting, or DVB is an accepted format for television broadcasting signals. There is a worldwide consortium that has patented the technology behind the various accepted television signals. This is so that all digital signals can be the same for all countries, as opposed to the analogue method of NTSC, Secam, and PAL.

D.A.B radio is Digital Audio Broadcasting, and basically means you can search the radio channels on a built-in keypad. I think that's it, but I'm not 100% sure...

The term DAB aerial in the radio industry stands for the type of system. DAB is an acronym for Digital Audio Broadcasting and is shortened to DAB since Digital Audio Broadcasting is a lot to say.