TOBY-R2 series - System integration manual
UBX-16010572 - R10
System description
Page 59 of 151
3.
If a new device reports the observation of Cell A CellLocate
®
is able to provide the estimated
position from the area of visibility
4.
The visibility of multiple cells provides increased accuracy based on the intersection of areas of
visibility.
CellLocate
®
is implemented using a set of two AT commands that allow configuration of the
CellLocate
®
service (AT+ULOCCELL) and requesting position according to the user configuration
(AT+ULOC). The answer is provided in the form of an unsolicited AT command including latitude,
longitude and estimated accuracy.
☞
The accuracy of the position estimated by CellLocate
®
depends on the availability of historical
observations in the specific area.
Hybrid positioning
With u-blox Hybrid positioning technology, u-blox cellular devices can be triggered to provide their
current position using either a u-blox GNSS receiver or the position estimated from CellLocate
®
. The
choice depends on which positioning method provides the best and fastest solution according to the
user configuration, exploiting the benefit of having multiple and complementary positioning methods.
Hybrid positioning is implemented through a set of three AT commands that allow configuration of
the GNSS receiver (AT+ULOCGNSS), configuration of the CellLocate
®
service (AT+ULOCCELL), and
requesting the position according to the user configuration (AT+ULOC). The answer is provided in the
form of an unsolicited AT command including latitude, longitude and estimated accuracy (if the
position has been estimated by CellLocate
®
), and additional parameters if the position has been
computed by the GNSS receiver.
The configuration of mobile network cells does not remain static (e.g. new cells are continuously
added or existing cells are reconfigured by the network operators). For this reason, when a Hybrid
positioning method has been triggered and the GNSS receiver calculates the position, a database
self-learning mechanism has been implemented so that these positions are sent to the server to
update the database and maintain its accuracy.