
Vehicular Repeater System
2. INTRODUCTION
The Futurecom MOBEXCOM DVRS® Vehicular Repeater is designed to interface with the Motorola XTL5000 Digital
Mobile radios and the 05 Control Head. It permits expanded operation of portable radios. The Vehicular Repeater system
consists of. a mobile radio, MOBEXCOM DVRS® Vehicular Repeater unit, a mobile radio Control Head and a RF
multiplexer. The Control Head communicates with the Vehicular Repeater and the mobile using a serial data protocol.
REPEATER MODES
The Vehicular Repeater operates in one of three modes. The mode of operation is selectable from the Mobile Control
Head by the mobile radio operator.
The three modes are known as the MOBILE, LOCAL and SYSTEM modes. The function and purpose of each mode is
described as follows.
Mobile Mode
In the MOBILE mode, the vehicular repeater is completely disabled. The mobile radio is operational and will permit
the mobile radio user to communicate conventionally, using the mobile radio. The mobile user may select the desired
mobile operating channel, adjust the receiver volume level and transmit using the microphone Push-to-Talk (PTT).
This mode is used when Repeater operation is not desired. The Vehicular Repeater System operates similarly to a
standard mobile radio system, as if the Repeater were not present. The RF multiplexer is disabled and the antenna is
connected directly to the mobile radio.
The MOBILE mode should be selected if several Repeater equipped vehicles are in the same area and another
Vehicular Repeater already has LOCAL or SYSTEM mode enabled.
Local Repeat Mode
In the LOCAL repeat mode, the Vehicular Repeater is enabled to permit communications among nearby portable
radio users and the mobile radio user. Repeater signals are not retransmitted by the Mobile Radio, so that
communications on the mobile channel will not be disturbed. However, all functions of the mobile radio operate
normally, except for scan, microphone mobile Push-to-Talk, scan activation, mode selection, zone selection, home
channel operation and mobile channel selection. When the LOCAL repeat mode is selected, the mobile radio scan is
deactivated and the mobile radio reverts to the selected mobile channel. Signals received by the Vehicular Repeater
receiver are heard in the mobile speaker and will also be retransmitted by the Vehicular Repeater transmitter. Signals
received by the Mobile receiver are heard in the Mobile speaker and will be transmitted by the Vehicular Repeater.
When signals are present in both the Vehicular Repeater and Mobile receivers simultaneously, the signal from the
Vehicular Repeater will have priority in the mobile speaker. (Note that the receiver/PTT and speaker priorities are
programmable.)
The mobile user will key only the Vehicular Repeater transmitter when using the microphone Push-to-Talk. The
Vehicular Repeater receiver has full priority over the mobile radio operator microphone Push-to-Talk. To respond to a
mobile signal, the mobile operator must enter either the MOBILE or SYSTEM mode to be able to transmit from the
mobile radio.
The mobile user may adjust the receiver volume level and transmit over the Vehicular Repeater using the
microphone Push-to-Talk.
The LOCAL mode, as the name implies, permits communications among portable radio users and the mobile radio
operator, without interfering with the mobile radio dispatch channels.
System Repeat Mode
In the SYSTEM repeat mode, both the Mobile Radio and the Vehicular Repeater are enabled to permit the full
exchange of communications among nearby portable radio users, the mobile radio user and the dispatcher and other
users on the Mobile Radio channel. Signals received by the Vehicular Repeater receiver are heard in the mobile speaker
and will also be retransmitted by both the Vehicular Repeater and Mobile transmitters. Signals received by the Mobile
receiver are heard in the mobile radio speaker and are also retransmitted out of the Vehicular Repeater transmitter.
However, all functions of the mobile radio operate normally, except for scan, scan activation, mode selection, zone
selection, home channel operation and mobile channel selection. When the SYSTEM repeat mode is selected, the mobile
radio scan is deactivated and the mobile radio reverts to the selected mobile channel. When signals are present in both
the Vehicular Repeater and Mobile receivers simultaneously, the signal from the Vehicular Repeater will have priority in
the mobile speaker. (Note that the receiver/PTT and speaker priorities are programmable.)
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