Cellular & Mobile Telephone System Information

Cellular System Description

The Cellular system divides a metropolitan area into a number of coverage areas or "cells". Each cell has a low power transmitter, with a specific set of radio frequency channels. The system has been assigned a 40 MHz band centered at 850 MHz. Each particular cell has two groups of channels (one transmit and one receive) assigned to it. Adjacent cells will have different channels assigned to avoid interference. As a vehicle moves from one cell to another, the call is transferred, or "handed off", to the next cell. This is accomplished through continuous signal strength measurements by the cell sites. Basically, the hand-off decision is made when the signal strength falls below a threshold level at one cell site and rises above a threshold at a neighboring cell site. The hand-off is accomplished without interrupting the conversation. The capability of the system is increased by subdividing the number of cells. The Cellular system provides the following advantages over the present day mobile system:

^ Readily available access
^ Significantly increased privacy
^ Improved voice quality
^ Easier to operate
^ "Full Duplex" operation, which means both parties can speak simultaneously.

FIGURE 1:

Mobile Telephone System Components

The Mobile Telephone System, as shown in Figure 1, consists of three main units: The handset, transceiver and speaker relay module. Additionally, the system has a microphone, and uses the existing vehicle speakers.
TRANSCEIVER - The transceiver is a standard 800 MHz radio telephone. It is located in the trunk compartment just below the package tray. The transceiver is installed at the dealer.

FIGURE 2:

SPEAKER-RELAY MODULE - This module is used to provide the interface between the transceiver and the speakers and is mounted in the instrument panel in the proximity of the radio, as shown in Figure 2.

SPEAKERS - The mobile telephone uses the existing entertainment system vehicle speakers, which are switched in via the speaker relay module.

FIGURE 3:

HANDSET - In the Mark VII, the handset (Figure 3) is located in the center console within reach of both front seat occupants. The, handset is installed at the dealer.

FIGURE 4:

MICROPHONE - In the Mark VII, the microphone is located inside the header assembly, as shown in Figure
4. In the Town Car the microphone is located inside the sun visor.
Operating Instructions

^ Punch in the telephone number desired (The telephone may be left in its mount while dialing). If an error is made press the Clr (Clear) Button and start over.
^ Press the orange Snd (Send) button to initiate the call. The green "In Use" message will illuminate. You will hear conventional ringing as the call is processed, followed by the called party answering. If you hear a BUSY SIGNAL, press the End button. To redial (even after a few minutes wait), press Snd, Release the handset and bring it to ear.
^ Using the "Hands Free Operation" the message "MUTE" will appear in the display when you press the Snd button. When called party answers, leave the headset cradled, press the Mute button and direct your conversation to the Hands Free microphone.
^ Press the End button to end the call.
^ If the red "No Svc" (No Service) message appears, you are temporarily out of range of Cellular System.

Each time the mobile telephone is turned on, the following events occur to insure that the unit is working properly.

1. Fourteen 8's will briefly appear in the display.
2. Each of the Status Messages will illuminate briefly.
3. A short tone will be heard.
4. The indicators located below the PWR and AUX buttons illuminate through one cycle red/green. If the unit is locked when turned on, the "LOC'd" message will appear in the display for six seconds and then extinguish, and the indicator below the PWR button will illuminate red.

To unlock the unit, enter the specific three digit unlock code using the keypad. The code must be entered as a three digit group and in the correct order. If an error is made in entering the code, press Clr and begin again.

To place calls:

1. The unit must be turned on and unlocked, and the "No SVC" indicator light must be extinguished. The handset may remain in its mount or held in your hand during dialing.
2. Enter the number (including any necessary area code, international code, or other access codes) using the keypad. There is no dial tone because you are entering the telephone number prior to placing the call.
3. As each digit is entered, you will hear a confirming tone and see the digit displayed. NOTE: The * is displayed as an A and # is displayed as C.
Telephone numbers up to 24 digits may be dialed, but only the last 14 digits dialed will be shown on the display. To review digits entered prior to the 14 shown, press and hold the Rcl button. If you enter a digit incorrectly, press Cir and start over.
4. To initiate the call press Snd. The green "In Use" message will illuminate.

If you hear a busy signal, press the End button. To redial (even after a few minutes wait), press Snd.
5. When the called party answers, release and lift the handset. At the conclusion of the call, press End. The "In Use" message indicator will extinguish.

Receiving a call:

1. When answering a call, simply press the orange Snd button on the handset, Hands Free operation is now active then the green "In Use" will light.
2. Continue the conversation in a normal voice using the Hands Free microphone and speaker.
3. When the conversation has ended, press the End button on the handset to terminate the call.

Handset Microphone Muting

The handset microphone may be turned off (muted) during a call. This allows the driver to converse privately with passengers, the handset earpiece remains active. To mute the handset microphone, press the mute button. Illumination of the "MUTE" message in the display confirms that the microphone has been turned off. To reactivate the handset microphone, press the Mute button (again).

Auxiliary Alert

The Auxiliary Alert feature allows the additional alerting device using the vehicle's horn, headlights, etc. to be activated for the third through seventh rings (5 rings) of an incoming call (20 seconds). This is useful if the user will be outside of his vehicle and expects a call. Your cellular telephone is allowed to ring up to 16 times (1 minute) before the call attempt is automatically cancelled. The internal alert ringer is operable for all 16 rings.

Unanswered Call Indicator

If the unit is left active and receives a call that is not answered, the message CALL will appear in the display, and the indicators below the PWR and AUX buttons will illuminate alternately red and green. If the ignition was left on, the CALL will appear in the display immediately. If the ignition was left off, as is more likely, the CALL message will appear when the ignition is turned on. Pressing "Cir" will remove the message.
Using the Telephone Without the Keys

With the ignition off, turn the mobile telephone on using the PWR button. The mobile telephone will turn on in the locked state. The unit turns itself off in six seconds unless the three digit unlock code is entered.

Roaming

Roaming is a feature that allows the cellular subscribers to obtain service in a system other than their home system. Whenever the mobile phone comes within range of a visited cellular telephone system, the Roam message will automatically illuminate to indicate that you are within range.

Removal and Installation

Antenna Removal

1. Grasp the antenna at its separation point and turn counter-clockwise applying moderate pressure.

Installation

1. When re-installing the antenna, twist clockwise by hand, until snug.

Control Unit Removal

1. Shut off control unit with the PWR button.
2. Release and lift the handset.
3. Detach the modular connector.
4. To re-install the unit, reverse the above procedure.

Cleaning

Clean the unit with a damp cloth, using a mild solution of dish washing detergent and water. Some household cleaners may contain chemicals which could seriously damage the component.