Today someone told me that when a device has connected to an AP, other APs in the room normally cannot see its packets, because:
- Adjacent APs commonly work at different frequencies to prevent interference
- The wireless network interface controller will not pass the packet that isn't addressed to it
- Sometimes the device does send probe packets, but it only happens when the device decides to roam
My questions are:
- Is what he said correct?
- If so, how can a WiFi positioning system, be it fingerprinting-based or triangulation-based, be able to detect the locations of connected devices using just a single AP, or do the APs have to work in promiscuous mode for WiFI positioning?