I did work on a project concerned with tracking via Bluetooth a couple of years ago. Depending on the way you try to locate the mobile devices one advantage of

I did work on a project concerned with tracking via Bluetooth a couple of years ago. Depending on the way you try to locate the mobile devices one advantage of Bluetooth can actually be its smaller range compared to a Wifi AP that's running at its full range. With regular consumer hardware it is basically impossible to use signal strength indication between an AP and a mobile device to do any kind of serious range estimation. Your best bet is therefore to use a whole grid of APs. The easiest way to locate devices is then to run all of them with a limited range and locate mobile devices based solely on proximity to a single AP. A more complex but potentially more accurate solution would be to run them with larger overlapping ranges and calculate the mobile device's location based on the intersections. Running too many Bluetooth APs that actively broadcast for peers, however, may have the unintended side effect of jamming the 2.4 GHz band. All in all, I actually agree that Wifi is the better solution nowadays. Symbian was the last smartphone OS that had Bluetooth set to visible by default. Since the switch to Windows all of the major smartphones will be invisible by default which was not the case in former years. Also, quite a few smartphone users will have Wifi enabled at all times which means their phones will actively broadcast for networks which makes them easy to track in a passive way using hardware that is already installed.