GF82.70-P-0003T Telephone (D Network) Function

GF82.70-P-0003T Telephone (D Network) Function
- with CODE (380) Preinstallation for MB phone "CTEL", complete
- with CODE (381) MB phone "Standard" in console on right side of dome
- with CODE (382) MB phone "CTEL" in console on right side of dome
- with CODE (383) With telephone "Standard" in console on right side of dome with integrated TELEAID emergency call system, hands-free system and antenna

Component Identification:

A phone call can be placed, depending on the equipment, via the following components:
^ Telephone handset (A34)
^ Portable CTEL (A34/6)
^ Radio (A2) Radio control panel and navigation unit (A2/56)
^ COMAND operating, display and control unit (A40/3)
^ Multifunction steering wheel

A prerequisite for this is that the device is operational after PIN entry and log-in. If the telephone is not needed, then it goes to standby mode.
The telephone switch-On/Off characteristics are controlled by the particular control and the system-dependent software in the control unit for the Media Oriented System Transport (MOST). The telephone interface (A34/4) or the telecommunications control unit (N112) is integrated into the MOST ring of the vehicle as is the radio control panel and navigation unit (A2/56) or the COMAND operating, display and control unit (A40/3).

The device represents the physical connection to the MOST ring and to the telephone antenna (A2/22) (model 211.2) or to antenna (A2/49a1) (model 211.0). The telephone antenna (A2/22) (model 211.2) or the antenna (A2/49a1) (model 211.0) is supplied with voltage by the telephone interface (A34/4) or the telecommunications control unit (N112) and transmits or receives the radio signals.
Antenna differences of the telephone systems are the result of vehicle-specifics (convertible, sedan, T-model wagon, etc.). This requires the use of different car antennas, speakers etc., depending on the vehicle and equipment. With all models it is possible to use the vehicle hands-free system for making calls, which increases driving safety. While doing so, the phone call is placed using the hands-free system microphone group (A67b1) and the vehicle speakers. The telephone handset (A34) or the portable CTEL (A34/6) remains in the cradle.

In the process, the display in the radio control panel and navigation unit (A2/56), in the COMAND operating, display and control unit (A40/3) or at the telephone handset (A34) provides a number of displays, which keep the user informed about the operating condition of the telephone.

Besides, displays appear in the multifunction display (A1p13) of the instrument cluster (A1), which keep the user informed of the operating condition of the telephone system. The volume of the speaker at the telephone handset (A34) can be adjusted separately on the device.
The volume of the hands-free system can be adjusted individually by the user at the radio control panel and navigation unit (A2/56), in the COMAND operating, display and control unit (A40/3) or at the telephone handset (A34), via the multifunction steering wheel, or with code (813) voice control system (VCS) via the voice control system.
The volume of any audio source switched on (radio, COMAND) is automatically reduced during a telephone conversation to ensure the maximum fidelity for the user over the hands-free system microphone group (A67b1).

D-network, general
The D-net (digital network) is designed based on the GSM standard (Global System for Mobile Communication).
This allows telephone calls to be placed worldwide to countries whose networks are also laid out according to the GSM standards and whose users have a GSM standard telephone. Moreover, s called roaming contracts are required for regulating the telephone traffic between these countries. Countries included in these contracts are given in the existing roaming lists. The D-net itself has a honeycomb-type structure for the greatest possible area coverage for mobile subscribers, whereby some areas may no be covered. The individual cells have a radius of 100 m to 35 km. However, this can be even smaller depending on the maximum telephone traffic (e.g. in large cities) or depending on the surface characteristics (mountains, buildings, etc.).

Transmission problems could occur if the user is located in valleys (dead spot) or in areas with a small number of transmission and reception stations.
However, this problem can usually be eliminated by moving to a different location.
16 carrier frequencies per cell allow up to seven calls per carrier frequency.
Transmission of the voice and data signals is accomplished digitally in the range of 900 to 1800 MHz. The system ensures maximum security against monitoring by third parties and provides additional services such as:
^ Fee display
^ conference calls, waiting function
^ identification of calling party
^ call relaying
^ Traffic information service
^ WAP and Internet

Moreover, with ISDN compatibility the D-network offers access possibilities to text and data stations (corresponding adapters required).
The D-network requires the following operating units:
^ BTS=Base Transceiver Station, for each cell
^ Concentrator (BSC = Base Station Controller, radio transmission station, for a number of cells)
^ MSC=Mobile Service Switching Center, for a number of cells

Each base transceiver station (BTS) is connected to the associated mobile switching center (MSC) via a base station controller (BSC). The connection between the base transceiver station (BTS) and concentrator (BSC) is accomplished via radio signal (pulsed signal) and the connection from the concentrator (BSC) to the mobile service switching center (MSC) via lines (permanently-wired 4-conductor cables).

The following units are included in the mobile switching center (MSC):
^ HLR Home Location Register
^ VLR Visitor Location Register
^ Authentication center (AC)
^ EIR=Equipment Identification Register Besides, the mobile service switching center (MSC) provides the interface for the transmission of the public telephone network (PSTN, in Germany to the Deutsche Telekom).

The purposes of the units listed are explained using 3 examples:
^ Telephone (D-network) log-in
^ Telephone (D-network) mobile subscriber to public telephone network
^ Telephone (D-network) mobile subscriber to mobile subscriber

Each subscriber in the D-net is listed in his mobile service switching center MSC or the home location register (HLR) stored for him. The network access authorization of the mobile subscriber is also checked in the authentication center (AC) located there. Moreover, defective or stolen units are identified in the equipment identification register (EIR). This ensures that such units are immediately identified when logging into the network. All subscribers from other home location registers (HLR) or other networks are identified in the visitor location register (VLR) It is possible to select between two versions:
^ Permanently installed
^ Portable CTEL (A34/6)