GF82.60-P-3020RI Digital Audio Broadcasting (DAB), Function

GF82.60-P-3020RI Digital Audio Broadcasting (DAB), function
- with CODE (537) Digital radio
- with CODE (833) Great Britain version


Function requirements
^ Status "Circuit 30 ON" or "Circuit 15R ON"
^ System is authorized and operating properly
^ The DAB L-band antenna (A95/1), left antenna amplifier module (A2/64) and the corresponding antenna structures are operating free of faults

General
The Digital Audio Broadcasting (DAB) function makes it possible to transfer several programs on one frequency; these programs are called the "Ensemble". Up to 64 frequencies are available fro DAB; in Great Britain, up to 7 of these frequencies can be received simultaneously; as a rule, this number is 2 to 3 frequencies. An "ensemble" can consist of up to 12 programs.

Each program can have subprograms (e.g. news announcement, summary of events, etc.). Only the "ensemble name", not the frequency, is displayed for the individual "ensembles".
DAB is a digital radio mode which eliminates the usual "FM/AM noise". However, short-term interruptions in reception of the "ensembles" are possible, because with DAB only two reception states are possible "Complete reception" or "No reception". The Digital Audio Broadcasting control unit (N87/3) allows reception of "Ensembles" in DAB format. The DAB functions are controlled by means of the COMAND operating, display and controller unit (A40/3). The information or displays required for operation are shown on the display of the COMAND operating, display and controller unit.

Operating instructions
DAB can be operated using the following components:
- Left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)
- Control buttons on the COMAND operating, display and controller unit
- Voice control on the voice control system (SBS), with code (512) COMAND APS including DVD changer

The left and right multifunction steering wheel button groups can only be selected in the memory list or station list. The "Ensemble" can only be changed using the buttons on the COMAND operating, display and controller unit or the voice control system's voice control.

Function sequence for DAB radio
- The DAB L-band antenna receives the DAB L-band signals for the local providers, usually from conurbation stations.
- The left antenna amplifier module receives DAB band III signals via the antenna structures for large-area provision, usually from stations with a large range or national stations.

The signals are forwarded to the Digital Audio Broadcasting control unit using coaxial cables. The Digital Audio Broadcasting control unit decodes the signals and forwards them as Pulse Code Modulation (PCM) signals to the COMAND operating, display and controller unit via the Media Oriented System Transport (MOST).

On vehicles with code (810) Sound system, the Digital Audio Broadcasting control unit transmits the PCM signals for audio output to the amplifier for sound system (N40/3) via the MOST. From there, the PCM signals for audio output are output via direct lines over the following speakers:
- Left door speaker group (H4/1)
- Right door speaker group (H4/2)
- Left rear speaker (H4/7)
- Right rear speaker (H4/8)
- Center cockpit speaker (centerfill) (H4/27)
- Subwoofer speaker (H4/29)

The audio signal for the subwoofer speaker travels from the COMAND operating, display and controller unit via MOST to the amplifier for sound system and from there, via direct lines over the subwoofer amplifier (N40/9) and then to the subwoofer speaker.

On vehicles except code (810) Sound system, the Digital Audio Broadcasting control unit transmits the PCM signals for audio output to the COMAND operating, display and controller unit via the MOST. From there, the PCM signals for audio output are output via direct lines over the following speakers:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker