On: Tracking traveler phones lets Cincinnati airport cut security line wait by third

[mandeepj]

> looks for devices over Wi-Fi and Bluetooth

There must be lot of devices which are not connected to these two. So, this makes their system not completely accurate.

They could have used other options like - 1. Sensors on the floor 2. Sensors on the tables where we put our stuff 3. How busy is x-ray scanner belt? 4. How fast people are getting through scanner door.

[_dp9d → mandeepj]

In all of your suggestions they would have had to pay for the sensors themselves.

By using the passenger's phones, they're essentially crowdfunding the cost of the sensors.

In both cases, they still have to pay for the "collector and analyzer"

[mandeepj → _dp9d]

Some people may even switch off their phones when they will come to know that they are getting tracked.

Another reason for their system's inaccuracy is - not many people use airport wifi. Most of us have data plans.

[function_seven → mandeepj]

> Some people may even switch off their phones when they will come to know that they are getting tracked.

They don't need to count each and every person to determine relative wait times, as long as the portion of wifi-enabled travelers is roughly the same in each area.

> Another reason for their system's inaccuracy is - not many people use airport wifi. Most of us have data plans.

You don't have to be connected to the airport's wifi for this system to work. The phone's wifi radio just has to be turned on.

[rasz_pl → mandeepj]

More advanced systems are build around SDR platforms and passively scan GSM band for TMSIs.

[ryan-c → mandeepj]

For wifi at least, it doesn't have to be connected, the radio just needs to be on.