The DETS Voice Break-in System for Digital Radio enables tunnel operators to replace audio programmes with live or pre-recorded announcements, providing information and instructions in the event of an emergency, without any disruption at the receiver.
The system monitors the live ensemble for all current audio service configurations and automatically manages the replacement of normal programmes with the emergency announcement using the same audio bit-rate. This ensures a seamless transition and avoids receiver reconfigurations, which would otherwise lead to a delay in the reception of announcements. To prevent the need for receivers to re-tune, the system maintains RF frame synchronisation when switching between live programmes and announcements, hereby avoiding disruption to the digital radio signal.
When an announcement is required, an RF switch is used to replace the conditioned off-air signal with the locally generated emergency broadcast. DETS inserts emergency audio and text messages in to DABand DAB+ Ensembles. The system’s seamless break-in of announcements and synchronisation of transmission framing ensures that listeners can be made aware of emergency situations with the minimum possible delay.