Some of our devices support 'cell tower fallback' to provide a rough location if a GPS (or Wi-Fi) fix fails. This can be useful in extending the localisation abilities of a device.
Falcon - All FW versions
Oyster2 - 2.17/3.17
Remora2 - 2.14/3.14
Yabby Cellular GPS - 2.19/3.19
Yabby Cellular Wi-Fi - All versions
TABLE OF CONTENTS
- Set up
- How does it work?
- Ensure your device firmware supports the feature
- Set the Cell Tower Fallback parameter to YES (found under the Advanced Tracking parameter tab)
How does it work?
Cell Tower Scan
If a GPS fix fails, then a cell tower scan is done. The serving tower is returned. The device will then report to the server:
- Cell ID
- Location Area Code
- Mobile Country Code (MCC)
- Mobile Network Code (MNC)
For integrators - this is Field 28 in the integration documents. Any cell scan results will be sent as an upload with log reason 49 - Cell Tower Connection.
Determining the location (Lat/Long)
These values in an of themselves don't constitute the Latitude and Longitude of the device for display on a map. The position must be calculated and this can be done through various location services like Google's Geolocation API. The data can be passed to this service via API call and the Lat/Long is returned. Services of this nature charge a fee per lookup or per month.
For the Falcon and Yabby Wi-Fi, this is integrated into Telematics Guru with a charge per lookup as per the Digital Matter price list.
For the Remora2, Yabby Cellular GPS and Oyster 2, Telematics Guru will simply ignore any cell scan data - so this feature is currently for those using 3rd party platforms only. It may be integrated in future if there is demand. Contact us if you require this feature on Telematics Guru.
A cell scan is typically accurate to within 1km. So it is useful for a rough idea of where your device is i.e - 'has it left the depot?', not 'what street am I on?'
As mentioned, the accuracy of a Cell Scan is not great in comparison to a GPS fix. It can be useful as a 'last resort' fix. If you are expecting to be regularly indoors, a device like the Falcon (combo GPS + WiFi, optional cell fallback) or Yabby Wi-Fi (WiFi + cell fallback) may be a better choice. Additionally the cost of look-ups must be factored in to the equation - however However this feature on the Remora2, Yabby Cellular GPS and Oyster 2 is useful for:
Tracking assets in shipping containers
Often GPS fixes will fail when a device is placed inside a shipping container, but the device can still connect to the cellular network. When out in the field, the asset can be tracked via GPS, and the device's Bluetooth functionality taken advantage of. A typical problem is that once the device is loaded into the container and GPS fixes fail, we may be able to get uploads but we lose all visibility of device location. It will report the exact same GPS location (i.e. the last valid fix) until the container is unloaded (maybe not until it reaches another country!) Cell tower fallback is enough to give us a rough location, so we know it left the port/depot/warehouse - which is invaluable when managing the movement of shipments as an operational tool.