Tyco Electronics MM102014V1 - Manual (Page 51)

MM102014V1, Rev. G
5.23.1.3 Additional XCOV-TG Mode Information
The talk group used for Extended Coverage for a Talk Group (XCOV-TG) communications is the talk
group that was selected at the V-TAC when it entered XCOV-TG mode.
However, at the V-TAC, the selected talk group and/or profile can be changed to another talk group
and/or profile when XCOV-TG is in use. The selected talk group and profile in effect when the V-TAC
transitioned to XCOV-TG mode will continue to be used to validate portable radio connections and filter
the network voice traffic sent to the portable radios.
The selected talk group and profile in use when the V-TAC transitioned to XCOV-TG mode is displayed
on the bottom line of the dwell menu preceded by an “X-”.
5.23.2 V-TAC GPS Interlock
The V-TAC GPS Interlock feature is enabled or disabled through programming by the system
administrator. If enabled, the V-TAC can transition from XCOV or XCOV-TG to the Mobile Radio mode
of operation based on the location and velocity of the VTAC (provided by GPS) in order to prevent a
rolling VTAC. This capability applies only to XCOV and XCOV-TG mode of operation.
The distance and velocity required for transition are programmed by the system
administrator.
The VTAC will transition from XCOV or XCOV-TG operation to the Mobile Radio mode of operation if:
• The distance traveled by the VTAC exceeds a maximum permissible distance from a reference point.
The maximum distance is configured via programming.
The reference point is the location of the V-TAC based on latitude/longitude provided by
the GPS when the V-TAC first transitions into XCOV or XCOV TG , either directly at
power-up, from V-TAC Mobile Radio mode, or from VTAC SOI mode.
Distance traveled is the current location of the VTAC, based on the latitude/longitude
provided by the GPS, from the reference point.
• The velocity of the VTAC exceeds a maximum velocity threshold in miles/hour. The maximum
velocity threshold is configured through programming. Velocity is based on the velocity information
provided by the GPS.
If location and velocity information are not provided by the GPS and the VTAC is in XCOV or XCOV
TG mode, VTAC GPS Interlock processing is suspended. When location and velocity information are
provided by the GPS, VTAC GPS Interlock processing is resumed, taking the first valid GPS position
coordinates as the location reference point and acting immediately on GPS provided velocity.
This is intended to cover the situation where the GPS is not operational. If the GPS is out of coverage, the
last location and velocity information provided by the GPS and will be deemed useable.
When the VTAC transitions from XCOV or XCOV TG mode to Mobile Radio mode the VTAC will
disconnect all connected clients.
51