[vigneshv_psg]

I am just curious. Wouldn't it be more easier to do this with specific devices than using the phones?

Each passenger can be given a smart card along with the boarding pass (or embedded in the boarding pass). The sensors could merely check for the smart card at certain points and determine how long it took for the passenger to clear security, etc. The airline can then collect the smart card back just before boarding when they scan the boarding pass. Seems like a simple solution that would work without much privacy concerns.

[hammock]

I've seen this done in airports before, only using a plain laminated card that you carry through the line - the low-tech solution. The card was used by the TSA to internally track wait times

[evan_]

They used to do this at theme parks as well

[tdfw]

Disneyland in Anaheim still does. They use it to update the wait time signs at the entrance to each ride and, just recently, their official wait time mobile app.

[morgante]

Sounds like a giant pain. Nobody (passengers or airlines) wants yet another card to carry around when we already have perfectly usable devices.

[ISL]

It's not easier than using a thing they already have.

[vigneshv_psg]

yes, but using a thing they already have comes with privacy concerns. it also depends on their wifi/bluetooth being in "discoverable" mode.