Fortunately, with xHE-AAC as well as the data applications, DRM broadcasters can change programme allocations and data rates at any time provided the total does not exceed the total available data rate.
The importance of being able to change the bit rate at will, is that, when, for example, there is an emergency warning, it is possible to reduce the bit rate to the sound programme to allow the transmission of the speech message at a low 8 kbit/s rate. Other use cases are different programme allocations which can be adjusted and used during the day and night or when pop-up stations are set up for live events.