The telephone fitted operates according to the international GSM standard. The connection between the cordless keypad handset (CKPH) and the telephone is established via the base station for the handset. Up to two cordless handsets can be registered to the base station. The base station is integrated in the GSM telephone module. The telephone can be operated via the cordless handset, the voice processing system or the Phone Board. The telephone module is connected to the MOST bus.
A second cordless handset is available as an optional extra for the tandem system. An eject box for the tandem system can also be fitted in the rear of the passenger compartment.
The telephone control module forms the central component of the system. It incorporates the electronic circuitry for controlling the system. It processes all control commands and bus data.
The GSM engine is an important component of the telephone control module. It incorporates the 8W HF transmitter output stage and a digital module consisting of processor, digital sound processor and handsfree module.
The cordless handset incorporates the following features:
- 12-key keypad (for entry of phone numbers or SMS text)
- Adjustable earpiece volume
- Handsfree toggle button (Softkey)
- Send/hang-up button (establish/terminate communication link)
- Battery charge level indicator and warning (visual or audible warning)
- Illuminated graphical display (max. 4 lines of 16 characters each)
- Range of up to 10 m from vehicle with unobstructed line of sight
The holder for the cordless handset, the card reader and the electronic charger are housed in the telephone drawer. The holder in the drawer has to hold the cordless handset firmly and securely when it is locked in position. The handset will only be charged if it is properly locked in the holder. The handset will only lock into the holder with the keypad facing downwards.
The analogue microphone signal is scanned at 44.1 kHz (MOST sampler rate). The MOST controller makes the digitized signal available to the telephone and other MOST nodes.
WDCT antenna
The WDCT antenna is designed for a frequency of 2.45 GHz using 50 Ω technology. It is used for communication between the base station on the telephone control module and the cordless handset. The WDCT antenna can be activated and deactivated in the Control Display. In countries where the use of this frequency for private purposes is blocked, the WDCT antenna may not be switched on.
Exterior antenna
Telephone communication takes place by way of the vehicle's exterior antenna.
The Phone Board consists of a 15-key keypad for use exclusively with the telephone. The Phone Board cannot be used to compose SMS (Short Message Service) text messages.
The MMI is used to display telephone functions by means of a status bar. In addition, a selection of user-defined phonebook entries can also be displayed.
The MFL has an integral combined Send/Receive button for the telephone. The volume for the handsfree function can also be adjusted on the MFL.
The microphone (voice) signal received from the telephone by the MOST controller can be processed by the voice processing system.
The ASK is the master for the MOST bus alongside the MMI. The ASK contains the power output stage for the speakers.
A second cordless handset is available as an optional extra. The second holder with SIM card reader and electronic charger can be connected to the transceiver as a tandem system (identical with standard equipment).
If two card readers are fitted (in front and rear of passenger compartment), the SIM card inserted in the rear card reader always takes precedence.
The following conditions must be met for the telephone to function:
- Cordless handset or handsfree system active
- WDCT base station active
- GSM engine active
The telephone can be operated via the cordless handset, the handsfree system or the Phone Board. If the cordless handset is not active (Standby), it can be woken up. Precondition: Cordless handset is locked in the drawer.
- Cordless handset
Terminal |
Behavior |
0 |
|
R, 15 |
Switching on phone on cordless handset possible |
R, 15 |
Switching off at cordless handset possible |
R, 15 |
Charging battery possible |
0 |
Charging battery for max. 1 hour |
- Telephone control module
Terminal |
Behavior |
0 |
Telephone off (after run-on time elapsed) |
0 |
Switching on phone on Phone Board possible |
R, 15 |
Telephone ON |
R, 15 |
Switching off phone on Phone Board possible |
Terminal 0: MOST inactive; Terminal R, 15: MOST active;
Action |
Reaction |
Button on cordless handset pressed when Terminal R or 15 on |
Lighting switched on for >= 10 sec. Pressing button again extends remaining 'on' time to >= 10 sec |
Button on cordless handset pressed when Terminal 0 on |
Cordless handset lighting also responds when Terminal 0 on |
Handset removed from holder |
Set lighting level on for >= 10 sec. |
In order to ensure that the handset is charged, it must make proper contact with the contacts in the drawer (eject box). If the cordless handset is properly inserted in the eject box and its battery charge level is below a specified minimum, charging is initiated.
The charging cycle is adapted to suit the battery temperature. CAUTION: the battery can only be charged if the ambient temperature is in the range 0...40°C. A fully charged battery will provide over 48 hours of standby time. The quick charge function (charging time < 1 hour) will provide about 30 minutes of call time.
In the service functions of the workshop tester, it is possible under the item ”Telecommunications”, to select ”Register cordless handset” and ”Deregister cordless handset”.
A cordless handset can only registered if at least one of the two memory spaces for the registration of cordless handset in the telephone control module is not occupied.
The ”Deregister cordless handset” function is used to delete the 2 cordless handset memory spaces in the telephone control module.
If it is no longer possible to deregister the cordless handset via the telephone control module, the cordless handset can also be deregistered without a connection to the telephone control module. It is enabled for renewed registration at a telephone control module. To deregister the cordless handset, carry out the following steps.
Country-specific telephone control module
Country-specific telephone control module
Also FBI (Flexible Bus Interface); the FBI can connect an I-bus navigation system and an I-bus telephone system to a MOST information/communication system. MOST bus/I-bus gateway.