Outstanding write-up! We actually built a business based on this technology (occuspace.io) and have had to address almost all the questions that you brought up. To answer some of them here:
Q: How accurate is BLE beacon count, as a proxy for occupancy?
A: It's very highly correlated but different dining locations, classrooms and library floors have very different correlation factors. Consider using other, perhaps more complex features, as well.
Q: How accurate is BLE beacon availability time, as a proxy for dwell time?
A: We don't believe it is very accurate given that BT MAC's randomize every 8-20 mins depending on manufacturer.
Q: Can we improve the accuracy by setting an RSSI minimum, for which devices weaker than it do not count, to ensure only those who are really nearby get counted?
A: That's a great idea. It's worth noting that different types of spaces and depending on where you installed your sensor, will have different threshold levels.
Q: How accurate is BLE beacon count, as a proxy for occupancy?
A: It's very highly correlated but different dining locations, classrooms and library floors have very different correlation factors. Consider using other, perhaps more complex features, as well.
Q: How accurate is BLE beacon availability time, as a proxy for dwell time?
A: We don't believe it is very accurate given that BT MAC's randomize every 8-20 mins depending on manufacturer.
Q: Can we improve the accuracy by setting an RSSI minimum, for which devices weaker than it do not count, to ensure only those who are really nearby get counted?
A: That's a great idea. It's worth noting that different types of spaces and depending on where you installed your sensor, will have different threshold levels.