Accurately tracking assets indoors is a recurring pain-point in the telematics industry. GPS/GLONASS signals have trouble penetrating buildings; and when the device does not have a direct line to these signals, it malfunctions.
So, how do you manage indoor assets, or assets that are frequently on the move between indoors and out?
WiFi Positioning System (WPS)
Four of our devices (PQ-Yabby Wifi, PQ-Falcon, PQ-Ranger and SimplePack Plus) feature WiFi Sniffing modules to track assets inside warehouses, factories, garages, basements, and other buildings where even the best GPS just doesn’t work.
So how does WiFi Positioning work?
- The WiFi Sniffing module on these devices scans for all WiFi access points in the vicinity.
- The device does not actually connect to the WiFi networks, it simply explores which networks (access points) are available around it, and measures signal intensity
- We also send the Cell ID of the tower that the device is connected to assist in the position algorithm.
- This information is then used to triangulate a position – Easy!
WiFi vs GPS
- GPS is more accurate but generally battles to get a fix indoors.
- WiFi is great to get a location even when indoors.
- WiFi is lower power – it only takes the device a few seconds to scan for WiFi access points, whereas GPS can take 30 seconds or longer for a cold start (we use GPS aiding data to speed this up, but GPS still uses more power on average).
- WiFi will not get an accurate location if the device can’t find WiFi access points. So, if it is in a remote location, then positioning will be limited.
What about Accuracy?
The accuracy of WiFi Positioning is impressive, especially in urban areas with a lot of WiFi access points. Expect accuracy between 10m to 40m in most locations.
When to use WiFi Positioning?
When indoors, traditional GPS devices will struggle to get a fix, which uses a substantial amount of power. This becomes a serious problem if the GPS is also battery powered. Devices with WiFi sniffing modules will use less power when tracking assets indoors, or tracking assets that frequently travel between indoors and out, such as:
Stock / Inventory on Palettes
And much more!
When not to use WiFi Positioning?
WiFi positoining isn’t needed when your asset has strong GPS signal, and it does not work well in remote areas where there isn’t nearby WiFi networks. Substantial data charges can arise if the device is constantly failing to locate any nearby WiFi networks.
DEVICES FOR WIFI POSITIONING
PQ-Yabby is our tiny, battery powered tracking device, available with either a GPS/GLONASS module (PQ-Yabby GPS) for primarily outdoor tracking applications, or WiFi Sniffing (PQ-Yabby WiFi) for indoor localisation. Given the device’s compact size, The Yabby is perfect for tracking smaller assets as the device can be concealed easily.
PQ-FALCON GPS + Sensor features both a WiFi Sniffing and GPS/GLONASS Module, which allows for a combination of GPS and WiFi tracking for managing assets practically anywhere – indoors or out. If the Falcon can’t get a GPS fix in a certain amount of time, it switches to WiFi Sniffing to conserve power. The amount of time it waits to switch to WiFi can also be configured by users. The Falcon is a larger, more advanced tracking device, with multiple customisable inputs, outputs, an I2C interface, and can be hard wired of battery powered to meet almost any tracking application.
SimplePack Plus is a battery operated multipurpose device having accelerometer, press-button, WiFi – sniffer and more. It can be used as a movement detector, orientation detector, run-time calculator etc. There is tens of different modes and use cases; most of them can be utilized with WiFi – location.