I have this project where I am trying to expand our app, that can transmit realtime location of the appuser by locating the position of the smartphone. I've spent several hours looking for the right kind of beacons, but I can't seem to understand which ones suits the best for my project.
What I am trying to achieve is to put beacons all over my workplace to be able to see the realtime location of everyone who uses the app within that area by using trilateration. I need to cover a large area of around 4.000m².
I am not looking for a pre-built software solution, but just the hardware to be able to integrate the tracking system into my already existing Android/IOS app.
So what I am trying to ask is what kind of beacon should I use. I've also seen some projects built with arduino, but it looks like they are all using an external transmitter, which is not what I am looking for. The smartphone with bluetooth enabled should be the only transmitter.
If you have any suggestions which beacon to go for, please let me know.
Thank you for reading and your help and have a nice day.
With best regards
Karuzo Rodriguez
Any BLE beacon will work similarly well for trilateration provided it advertises at 10Hz (more Hz are better) and is set to the strongest transmitter power allowed. If relying on batteries for power, the aforementioned transmission settings will use batteries relatively quickly, but these settings are critical to positioning accuracy using trilateration because you need a strong signal and lots of statistical samples of the RSSI.
If you want to use BLE trilateration to cover a large area, the beacons must be placed such that there are always at least three within a 2 meter radius of any point. The reason is that the error rate on BLE RSSI is so high that it is only useful for trilateration when both transmitter and receivers are close together.
Using the above technique, you can probably get position accuracy of 0.5-1.0 meters. This is not much better than just using the "closest beacon" as the position estimate, which will give you 2.0 meters accuracy. Trilateration simply fine-tunes the position estimate then the beacons are already very close to the mobile phone receivers.
Placing three beacons in every pi*2m^2 (13 square meter) area can get pretty expensive and tedious. Because of this, you may want to consider an alternative technique called "RSSI Fingerprinting" which can achieve better accuracy than trilateration with far fewer beacons. This works because that technique does not require the signal to be strong enough to be correlated with line of sight distance. Even beacons at greater distances or those obscured by obstructions are useful to the positioning estimate.