Doing accurate triangulation (localization) of a bluetooth receiver from a bunch of active bluetooth nodes is maybe a little more difficult than it seems. Cert

Doing accurate triangulation (localization) of a bluetooth receiver from a bunch of active bluetooth nodes is maybe a little more difficult than it seems. Certainly a great idea in theory, but the accuracy of your localization will depend on the signal propagation model you apply to the received signal strength (RSS) that the phone provides. I would bet that it's difficult to find a phone that will give you signal strength in dBm at a high update rate. I worked on a localization project using passive RFID tags and an RFID reader (a more power efficient setup than having active bluetooth nodes). Especially in a store/mall type environment with many people moving around, I think it becomes hard to get a decent model of expected signal propagation (mainly due to constantly changing multi-path signal amplitude). All of that said, for your application you might be able to get by with the reduced accuracy (within 10 feet might work?). With bluetooth, you also have to consider the number of connections a bluetooth receiver can handle. That will probably greatly restrict your density of nodes. RFID again holds an advantage here, in that RFID is a very low-level interaction, while bluetooth is much higher level. This problem just screams RFID. Too bad everybody's phone doesn't have a built-in RFID reader... or a software radio!