User's Manual

repeating base-to-portable (HUB will also disable this), unless the coded squelch
requirements of the mobile radio are met. Button presses (that is, Volume, Mode, etc.) on
the priority mobile unit will also be transmitted by the VRS.
3. Operation of VRS
Options
The following sections describe the operation of CPS field-programmable options of the
VRS. This includes information about when to use an option and compatibility between
options.
Base Repeater
For two-frequency simplex systems using a fixed-site repeater, you can enable the base
repeater option. This adds 300 ms of delay to the prioritization routine to account for the
fixed repeater attack time. This allows non-priority mobiles to detect any priority mobile
in the system through the base repeater.
Mobile Detector
The Mobile Detector feature allows the user to operate VRS units with two-frequency
simplex dispatch systems without a base repeater. This feature allows the automatic
multi-unit priority resolution algorithm to function in the above scenario. When this
feature is activated by the CPS, a non-priority VRS will send a message to the mobile to
enable a "Listen Around" feature when a proper portable PL is received.
"Listen Around" switches the mobile radio's receive frequency to match that of its
transmit frequency of the steered mode. The non-priority VRS will count down in priority
if its corresponding mobile does not detect the repeated transmission on the "Listen
Around" frequency. When the portable is dekeyed, the non-priority VRS will send a
second message to the mobile to disable "Listen Around" and return to normal operation.
This feature does not use any additional user modes in the mobile.
NOTE: The Mobile Detector feature only works on conventional modes. Trunked
modes will be unaffected.
VRS Transmit PL Generator
The transmit PL generator, when enabled, causes the VRS to transmit (base-to-portable),
with specific field programmable PL tones. The selected VRS transmit PL frequency
cannot be the same as any of the VRS receive PL frequencies that the portable uses to
access the vehicular repeater.
VRS Mode Steering
The VRS steering option gives the portable operator the ability to select the current
mobile radio mode via PL tones. The total number of Mode-Steered modes can not
exceed eight (including emergency, message, and status). The operator may program as
many as eight such tones, along with corresponding mobile mode numbers, into the