Bluetooth Location Fail Victim image


There’s one LPWAN technology, LoRaWAN, that pretends to offer real-time geolocation when for all practical purposes it does not. Still, a few of its backers promote this capability — which is at best characterized as a hack — and hope customers don’t get wise until after the implementation. Other bloggers are catching on as well:

But even worse is a short range technology that pretends to be a wide area geolocation technology as well. Here is a tragic case of a Bluetooth tracker, advertised as having a wide area geolocation capability, failing to locate a lost Alzheimer’s patient after 12 days. 12 days and counting. And they still can’t find him.

Lost car keys are one thing and Bluetooth is not bad for finding low-value items wedged beneath your living room seat cushions. And if you want to pretend that you really do love your mother-in-law’s spoiled dog, give her a Bluetooth tracker as a gift and then feign shock when she can’t find him when he goes missing. (OK — that wasn’t nice.) Bluetooth has its uses in the IoT.

But marketing a short range technology like this as a wide area tracking device and allowing (or at a minimum, not warning against) its use on human beings crosses a bright line. I don’t know the fate of this Alzheimer’s patient and hope and pray he will be found safe and sound, but folks in the Bluetooth tracking business should be paying attention.

With an average range of about 30 feet, using Bluetooth to track something — especially something very valuable — over wide areas is just usually not done. Bluetooth is a Personal Area Networking technology — as in, a Fitbit or a Sonos speaker — and certainly not a Wide Area Networking technology. In my experience, the handful of people I have seen putting Bluetooth trackers on dogs or bikes do so based on utter technical naiveté, bad marketing hype, or hearsay from other uninformed users. Like “My brother-in-law told me I could use it on my dog and if she went missing the Bluetooth tracker would find her via satellite. Or via the cell phone network.”

The community finding feature that this article references what provides the makers of this Bluetooth tracker with the weak “cover” for the wide area networking claims. (There are other Bluetooth folks out there doing the same thing, last time I checked.) Unfortunately, without massive numbers of concurrent users actively invoking their tracking app, the probability of a detection is — as the 12-day delay in locating the missing patient demonstrates — very, very small.

How small?

Covering the city of Daytona Beach (where the Alzheimer’s patient went missing) requires enough active users — each with ~2,800 square feet (that’s 30 feet² x π) of Bluetooth “coverage” — to cover 65 square miles of city (1.8 billion square feet). Or about 647,000 concurrent users just in DaytonaBeach. All distributed evenly throughout the city, all with ~30 feet of Bluetooth coverage, all with their phones turned on and the tracking app enabled. And all of this assumes the patient didn’t run off to another town nearby.

And this is made somewhat more problematic by the U.S. Census Bureau, which says the total population of Daytona Beach is 63,000 people.

End user confusion about how wireless technologies work is pretty rampant. High powered cellular technology is the paradigm that I have observed makes some of this possible. Misconceptions about how GPS works are even more abundant. Bluetooth radio spec sheets claim certain capabilities, often based on “best case” conditions that don’t reflect a real world environment. And in a rush to turn Bluetooth into a relevant Internet of Things technology, hacks were invented to make it sound more compelling as a tracking technology than it really is.

It is possible the Bluetooth tracking company here warned their customers against tracking humans with their product (I didn’t see it on their website …), but when you market a community finding feature replete with “success stories” of objects like lost bicycles, and then claim that the range is potentially “limitless”, people are going to take your word for it and get creative.

If you want real-time tracking over wide areas using a device that provides multi-year battery life and GPS-based location, there are more serious technologies out there than Bluetooth.