GF82.70-P-0007-05CW Mobile Phone System, Establishing Connection to Mobile Phone Subscribers

GF82.70-P-0007-05CW Mobile Phone System, Establishing Connection To Mobile Phone Subscribers
- with CODE (523) MB Audio 20 radio
- with CODE (510) Audio 20 with CD changer

Component Identification:

Function requirements
^ Status "circuit 30 ON" or "circuit 15R ON".
^ Enabled Subscriber Identification Module (SIM) card inserted into mobile phone.
^ Mobile phone and "master control unit" switched on.
^ Correct Personal Identification Number (PIN) entered, if set on the mobile phone.
^ Mobile phone system operating error-free.
^ A mobile telephone network is available in sufficient strength and quality.
^ Compatible mobile phone inserted into the mobile phone cradle (A34/15) (comfort telephony) or Bluetooth mobile phone in the vehicle and registered with the "master control unit" (basic telephony).

General
Mobile phone subscriber A (A) has logged into the mobile telephone network via his/her Mobile Service Switching Center (MSC), and mobile phone subscriber B (B) has logged into the mobile telephone network via his/her Mobile Service Switching Center B (MSC (B)) and both are noted in their Home Location Register (HLR) there.
Now both mobile phone subscribers can call each other via the following communication path:
^ Mobile phone
^ Base Station Controller (BSC)
^ Base Transceiver Station (BTS)
^ Mobile Service Switching Center (MSC) or Mobile Service Switching Center B (MSC (B))

However, if mobile phone subscriber A (A) or mobile phone subscriber B (B) logs into the mobile phone network outside of the reception range of his/her Mobile Service Switching Center (MSC) or Mobile Service Switching Center B (MSC (B)), then the two are entered into the Visitor Location Register (VLR) for the best sited Mobile Service Switching Center (MSC) via the following communication path:
^ Mobile phone
^ Base Station Controller (BSC)
^ Base Transceiver Station (BTS)

The best sited Mobile Service Switching Center (MSC) automatically contacts the responsible Home Location Register (HLR) for the Mobile Service Switching Center (MSC) for mobile phone subscriber A (A) and Mobile Service Switching Center B (MSC (B)) for mobile phone subscriber B (B) and reports the current location of mobile phone subscriber A (A) and mobile phone subscriber B (B).
If mobile phone subscriber A (A) wants to call mobile phone subscriber B (B), he/she enters the subscriber's phone number. This telephone number can be used to determine the location of mobile phone subscriber B (B) from his/her Mobile Service Switching Center B (MSC (B)). With the information on the location, the mobile phone system then transfers the call from mobile phone subscriber A (A) to mobile phone subscriber B (B) via the best communication path.

The mobile phone system also automatically searches for the most favorable communication path during a phone call in order to minimize transmission losses. The transmission path in the mobile telephone network consists of the following:
^ Mobile phone
^ Base Station Controller (BSC)
^ Base Transceiver Station (BTS)
^ Mobile Service Switching Center (MSC) or Mobile Service Switching Center B (MSC (B))