The challenge with today’s Bluetooth trackers

Bluetooth tag trackers are new devices on the market intended to keep us from ever again losing our valuables. These compact devices use Bluetooth low energy to communicate with your phone and allow you to locate missing items using the last known location given by your smartphone’s GNSS receiver. You can even make some tag trackers beep to help you track them down.

Headlined by Tile in US and Chipolo and Wistiki in Europe, Bluetooth tag trackers have been among of the most innovative and successful consumer electronics of recent years. They leverage Bluetooth low energy not only as a smartphone communication protocol, but also as a simple positioning technology, providing a rough reading of the device’s location relative to your phone. 

Out of range
Despite the hype, current implementations fall far short of their potential. A first issue is range, which is limited by the very technology that enables them. On paper, Bluetooth low energy’s range is 150ft, or about 50m. But anyone who’s used the technology knows to what extent walls, floors and ceilings, and other factors such as WiFi or Bluetooth interference can cut it short. Tile’s nominal range, for instance, is stated as over 30m, but its website explains that it works best only up to 10m.

A second issue is motion. As soon as an object moves out of range, it’s effectively gone from the tag tracker’s point of view. On their own, today’s Bluetooth tag trackers are incapable of locating that smartphone you left in the taxi, your stolen bike, your pet, or your missing child. Tile uses crowdsourcing to help get around this: if another Tile user is within range of your Tile, they can send you its location. But this kind of crowdsourced positioning is brand-specific and its success depends on the popularity of a certain company’s tag tracker.

Onboard positioning
The obvious answer to these issues would be GNSS positioning with cellular connectivity. While Bluetooth only works up to 50m in ideal conditions, GNSS together with cellular connectivity have no such range limitations. And extremely low-energy cellular communications are being made possible by the advent of Low-Power Wide-Area (LPWA) networks and new low-speed LTE categories in an increasing number of countries around the world.

This brings us to a third issue: energy. Today’s GNSS modules often require a sizeable battery, which makes them difficult to integrate into Bluetooth tag trackers, which need to be small and light.

But a solution is in sight. u‑blox’s newest GNSS technology, Super-E mode, which is used in the recently released ZOE-M8B SiP, changes the game by dramatically cutting power consumption to a third. Lower power demand translates to smaller batteries and ultimately, a lightweight and slim design.

With GNSS positioning and cellular connectivity built right into your tag tracker, that sinking feeling that comes with losing a precious belonging could become a thing of the past. You’ll be able to rest assured that your devices are accounted for, even if they break out of Bluetooth’s limited range. But in closing, a word of warning: recharge your tracker’s batteries. If they die, that dreaded feeling could once again come back to haunt you.

Written by Florian Bousquet, Market Development Manager, Product Center Positioning, u‑blox.