GF82.60-P-0006R Satellite Radio (SDAR), Function

GF82.60-P-0006R Satellite Radio (SDAR), Function
- with CODE (536) SIRIUS satellite radio

Component Identification:

The satellite radio (SDAR) permits the reception of additional radio channels (digital stations) that are broadcast by satellites or terrestrial gap-filling transmitters.
"Sirius Satellite Radio" must be enabled by the provider to permit reception.
When started up for the first time, the telephone number and the provider ID are displayed in the "SAT menu" of the COMAND operating, display and controller unit (A40/3).
After being enabled, between 100 and 224 additional stations can be received. The SDAR function is activated via the "SAT" button on COMAND. Station selection and station display take place in the same way as for operating the radio functions.

In addition to the audio signals, the following supplemental information that accompanies the program are evaluated:
^ Artist
^ Title
^ Music category

Broadcasting the signals
The SIRIUS satellite radio signal is broadcast three times in optimum situations (via 2 satellites and one terrestrial gap-filling transmitter) to ensure universal reception. The 1st satellite transmits 4 s ahead of the 2nd satellite and the gap-filling transmitter.

These 4 s of audio programming are buffered in the SDAR control unit (N87/5) to bridge short signal interruptions caused by, for example, bridges, underpasses or leafy forests. The gap-filling transmitters, however, are only used in densely populated conurbations, as here there is a very high risk of the satellite signals being impaired by infrastructure (e.g. tower blocks). In less populated areas without gap-filling transmitters, the system forms an optimal signal from the two receivable satellite signals.







Receiving signals
The SDAR antenna (A2/82) receives the S-band signals from the satellites or the gap-filling transmitter and forwards them to the SDAR control unit (N87/5). The SDAR control unit decodes the signals and transfers them to COMAND.

The transfer takes place in vehicles up to 31.5.04 via digital data bus (D2B) and as of 1.6.04 via Media Oriented System Transport (MOST).