Antenna system (ATS), function - GF82.62-P-0001GU

MODEL 463.249 /271 up to 31.8.08 as of model year 2007 

General information 

The antenna system integrated in the vehicle enables services such as radio, satellite radio, telephone, navigation and telematics services to be provided. The signals for radio remote central locking are also received and forwarded. The various antennas are designed according to their special reception and transmission ranges. They receive or transmit information by converting electromagnetic radio waves into electrical voltage signals and vice versa.

The system is made up of the following component functions:

• Function sequence for radio reception
• Function sequence for satellite radio
• Function sequence for global-positioning system (GPS) reception
• Function sequence for receiving and transmitting telephone signals
• Function sequence for central locking system and access authorization signal
• Function sequence for emergency call

Function sequence for radio reception 

The side window antenna (A2/33) integrated into the rear left side window receives the AM/FM signals. These AM/FM signals are filtered and amplified by the amplifier module 1, window antenna (A2/71). The COMAND operating, display and controller unit (A40/3) receives these AM/FM signals directly.

Function sequence for satellite radio 

The satellite digital audio radio (SDAR) antenna (A2/82) receives S-band signals from satellites and from terrestrial fill-in transmitters and transmits them to the SDAR control unit (N87/5). The SDAR control unit decodes the S-band signals and forwards them over Media Oriented System Transport (MOST) to the COMAND operating, display and controller unit.

Function sequence for GPS reception 

The GPS signals received by the front left GPS antenna (A2/23) are routed over the antenna splitter (A2/5) as required to the COMAND operating, display and controller unit or the emergency call system control unit (N123/4).

Function sequence for receiving and transmitting telephone signals 

The telephone signals are transmitted and received over the telephone and fax antenna (A2/22). The telephone antenna is connected directly with the E-net compensator (A28/3), which filters and amplifies the signals. The E-net compensator is connected over the radio and cell phone antenna splitter (A28/1), as required with the mobile phone via the telephone handset (A34) or with the emergency call system control unit.

Function sequence for central locking system and access authorization signal 

The central locking system and access authorization signal from the transmitter key (A8/1) is received by the central locking system antenna (A2/34) integrated into the windshield. The central locking signals are routed over the right antenna amplifier (A2/65) filtered and digitized to the rear signal acquisition and actuation module (SAM) (N10/2), where they are then forwarded over the interior CAN to the electronic ignition switch control unit (N73).

Function sequence for emergency call 

The GPS signals received by the front left GPS antenna are forwarded over the antenna splitter to the emergency call system control unit.

The telephone signals transmitted and received by the telephone antenna are routed over the E-net compensator, which filters and amplifies the received signals. The radio and cell phone antenna splitter connects the E-net compensator to the emergency call system control unit.

If the emergency call system control unit is unable to set up a telephone call over the radio and cell phone antenna splitter, the emergency call system control unit switches straight to the emergency call antennas (A2/52) um.