User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 13
Reporting Geofence Violations
To avoid nuisance geofence violations, a 30-meter diameter circle is established
with the center point being the current position of the TrimTrac 1.5. Before a
geofence violation is recorded, this circle must be 100% either inside or outside
the geofence area or, if the geofence is a boundary crossing type, 100% crossed
over the boundary line on either side. The fixed 30-meter diameter is the typical
positional error one might experience in an urban environment where reflected
signals, multipath and interference may influence the position solution.
Inclusive geofence violations will be reported if the TrimTrac 1.5 is outside both
geofence areas. Conversely, if the TrimTrac 1.5 is inside either of the geofence
areas, then no violations will be reported.
Exclusive geofence violations will be reported if the TrimTrac 1.5 is inside either
geofence area. Conversely, if the TrimTrac 1.5 is outside both geofence areas,
then no violations will be reported.
Whenever a geofence violation (boundary crossing, inclusive or exclusive) has
occurred, the TrimTrac 1.5 will transmit at least once to the server application
assuming GSM coverage is available. In the case of inclusive and exclusive
geofence violations, the device will continue transmitting reports until the device
re-enters an inclusive area or exits an exclusive geofence, respectively.
Upon the initial violation of an inclusive or exclusive geofence, the TrimTrac will
send a new POSITION_REP and a RESP_GEOFENCE_CONFIG message. If
SMS is being used, both messages will be included in a single SMS message.
The POSITION_REP will have the TriggerType set “2=Alert”, the position that
first triggered the violation notice and the Geofence Status field will be set
“1=Violation”.
The RESP_GEOFENCE_CONFIG message will denote which particular
geofence was violated. Only the most recently violated geofence will be
identified even if more than one geofence had been violated concurrently.
The device will continue transmitting POSITION_REP and a
RESP_GEOFENCE_CONFIG message so long as motion and the geofence
violation persists. Each new POSITION_REP will also have the TriggerType set
“2=Alert”. Similarly, if the device is unable to get a subsequent position fix or if
the IDLE Timeout, T1, has expired due to no motion, the STATUS_MESSAGE
with have the TriggerType set “2=Alert”. In all cases, the Geofence Status flag in
either the POSITION_REP or STATUS_MESSAGE will be set “1=Geofence
Violation” until a new position fix that is not in violation with the geofence
parameters is computed.
In the case of boundary crossing geofence, the TrimTrac will report once and only
once each time a geofence boundary is crossed by sending a new
POSITION_REP and a RESP_GEOFENCE_CONFIG message. If SMS is being
used, both messages will be included in a single SMS message. The