Digital Switchover (Disclosure of Information) Bill

The Secretary of State referred to people buying new digital sets. One of the difficulties is that they do not always know whether they will be able to get a signal. They are told that if they cannot get a signal now it is because it is at only a weak strength but will be boosted at switchover, and that in the final month before switchover it will run at the higher strength. If that is correct, why is it not possible for the digital signal to be increased for trial periods beforehand, as was done with BBC 2 when it was introduced, say between 2 am and 4 am on a Wednesday?