If you do a Google search on tracking devices, you’ll come across thousands of products advertising to do more or less the same thing. The number of different trackers available on the market can be overwhelming, and you may have seen products labelled as “GPS trackers” when in fact they use a different method of tracking. Hopefully, this will give you clarity on the different types of tracking devices.
(A typical Bluetooth tracker. Photo by Bojollo, via WikiMedia Commons)
Bluetooth is a short-range radio frequency used to transmit large amounts of data over short distances. Many wireless devices utilise Bluetooth, such as wireless computer keyboards and mice, portable speakers and most mobile phones will have Bluetooth functionality.
Bluetooth tracking devices are generally easy to use and very inexpensive with no ongoing costs. Once you’ve activated Bluetooth on your phone and connect it to the tracker, you can ping its location. Some Bluetooth trackers also work in reverse: by pressing a button on the tracker, you can locate your phone.
The downside is that Bluetooth is short-range, so it can only track something that is nearby. This means long-range vehicle tracking would be impossible and why many Bluetooth trackers are advertised as cheap and simple solutions for locating misplaced items, such as keys, bags and phones. Obstuctions such as walls, furniture and even people can interfere with their effectiveness. While the accuracy and range of Bluetooth trackers can vary between brands and products, generally, they use categories to show the distance between two devices rather than exact measurements: immediate (within 1 metre), near (2-10 metres), far (10-40 metres) and unknown (above 40 metres).
Fun Fact: The name “Bluetooth” comes from the 10th century Danish-Norwegian King, Harald Gormsson, who was nicknamed Bluetooth.
(A RFID reader used to inventory chemicals in a lab. Via WikiMedia Commons)
"RFID" stands for Radio Frequency Identification and uses radio waves to ping the location of tagged items. If you’ve been to a shopping centre or department store, you would have encountered a simplified version of this technology. The anti-shoplifting alarms in the entry ways use RF tags to trigger the alarm if a tagged item passes through.
To track a tagged item, two components are needed: the RFID tags and a specially made RFID reader. When turned on, the reader will send out radio waves which will ping the location of the tags. Unlike the tags you find in shopping centres, RFID tags are unique, and the reader can identify the different types of tags and accurately measure the distance between the reader and tags.
RFID is mostly used for industrial tracking, such as livestock, railroad cargo and airline luggage. So, a consumer-grade RFID tracker may be difficult to come by. While RFID trackers have a longer range than Bluetooth, it can only reach up to 100 metres, which, again, is impractical for tracking vehicles over long distances. Much like Bluetooth trackers, they can only tell you how close you are to the tagged item, rather than show an exact location.
(Public Wi-Fi - be careful what details you enter. Photo by Stolbovsky, via WikiMedia Commons)
Wi-Fi tracking works by approximating the distance between the tracker and overlapping Wi-Fi hotspots. The more hotspots available, the more accurate the measurement.
Even if you don’t actively use a Wi-Fi tracking device or app, you may have been subject to Wi-Fi tracking unknowingly. The free public Wi-Fi you connect to at your favourite shopping centre may be using the Wi-Fi hotspots to track your movements and seeing which parts of the shopping centre you visit the most.
Of course, Wi-Fi tracking can only occur in areas where hotspots are available. While urban areas are a viable location, in remote and regional areas, where public hotspots are few and far between, Wi-Fi tracking is unreliable.
(Black Knight GPS Tracking Devices use the 3G network)
GPS trackers utilise the publicly available GPS network. Currently, there are 30 satellites in orbit which make up the GPS constellation. Anywhere in the world, a minimum of 3 satellites are “visible”. Through a process called trilateration, they calculate the distance of the tracker by drawing a virtual sphere around the satellite, with the radius set by the distance between the tracker and satellite. Where the spheres intercept is the location of the tracking device. Therefore, a GPS tracking device is essentially a node which the satellites get a fix on.
GPS signals are available anywhere in the world, making GPS trackers ideal for tracking vehicles and fleets. However, most GPS tracking devices use the cellular network to transmit their location data. While this is ideal for urban areas where cellular connectivity is widespread and strong, in regional areas, where the cellular networks are weaker, GPS tracking may not be possible.
Also, different GPS trackers may use different networks: either, 2G, 3G or 4G (and in the future, 5G). While in Europe, 2G is still available (until at least 2020), in Asia, Australia and the US, 2G is either completely shut down or being phased out. Therefore, before purchasing a GPS tracker, make sure you look up what network is available in your country, check for any future network shut-offs and which networks the tracker can connect to.