
Tracking traveler phones lets Cincinnati airport cut security line wait by third - cleverjake
http://www.theverge.com/2015/3/12/8203555/cvg-airport-cut-security-times-with-phone-tracking
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softgrow
Can't help wondering why they have the "choose the line" step. An obvious
improvement is to have one line and direct passengers from the end of the line
to the next available station.

Then again, a better solution is to staff all screening stations all the time
or build more. Why do we wait passengers wait for a minimum wage screening
person? By do this we effectively say the passengers time is worth nothing.
Their employer might no appreciate them having "idle time" with no-one to
screen but I'm sure the passengers would sure like it. We don't mind
firefighters and paramedics having down time, this should be extended to
airport screeners.

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mistermann
I totally don't understand this, I would presume each line is processing
people at 100% (of their capability) - how does controlling what line a person
gets into going to shorten aggregate processing time unless some processors
are sitting entirely idle, which we all know would never happen.

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anonymousDan
I'm pretty sure there is some fundamental queueing theory to back this up, as
it's the main takeaway I had from a queuing theory course I took in college.
Can't remember the details though, so I'm not sure it would still apply if a
single queue entailed long walks from the head of the queue to the nearest
available 'processor'. EDIT: more background here
[https://possiblywrong.wordpress.com/2010/12/26/why-
multiple-...](https://possiblywrong.wordpress.com/2010/12/26/why-multiple-
checkout-lines-are-not-all-bad/) It appears you might be right in practice.

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mistermann
From your link:

"for 3 cashiers, it’s about 3 times faster than having a single line for each
cashier.”"

I would very much like someone to take me to a place in the physical world and
show me an improvement of this magnitude. I simply cannot see how (in a
setting like a bank or grocery store) this theory is nothing short of absolute
insanity.

EDIT: I just watched that video - is that guy trolling viewers? If you lose
1/3 of your cashiers, it has _no effect on total throughput if you are using a
single line queue_?

Just wow.

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sjm-lbm
Probably not helpful, but after reading this I can't stop wanting to make a
device that appears to be ~20-30 devices by randomizing its MAC address
quickly and causing extra staff to be sent to my line any time I was at a
place that used a system like this.

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omonra
You're not getting staff directed to your line, you're just screwing with
other passengers who are fed erroneous data:

"The system allows the airport to display to passengers how long the wait in
each of its security lines is."

All that system does is show you (ie passenger making decision where to go)
which line has fewest people in it.

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forrestthewoods
There's nothing erroneous about reporting random mac addresses. I think that
should be the default behavior for devices. Mac addresses shouldn't be used
for tracking. If the airport reports valid data in an incorrect way that's
their fault.

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Dylan16807
Random MAC is fine. Pretending to be 20 devices is obnoxious.

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bloodorange
No, it's not. One is free to preserve their privacy by using 20000000 if not
20 device MAC addresses. The aim is not to be tracked - which would imply
changing the MAC address regularly.

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Dylan16807
Regularly is fine. Maintaining 20 simultaneous MAC addresses screws up things
like DHCP and QoS.

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guelo
When iOS 8 came out Apple announced a MAC addresses randomization feature to
prevent device scanners like this one. But after people tested the feature it
turned out that the scheme only works under a very narrow set of conditions
that makes it nearly useless. I haven't heard if this has changed in 8.1 or
8.2 but hopefully Apple will move to stop these shenanigans, as well as
Google's Android.

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dublinben
Until that happens, you can prevent this kind of tracking by turning your WiFi
radio off. For battery life purposes, it's wise to do this anyway when you're
not in a location where you intend to be using the WiFi connection.

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walterbell
Are there any local-only contextual apps which can turn wifi on or off based
on GPS location?

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cesarb
I like Wi-Fi Matic
([https://sites.google.com/site/wifimaticapp/](https://sites.google.com/site/wifimaticapp/)).
It uses the phone network cell identifiers instead of GPS (so it works even
where you can't get a GPS fix), and auto-learns the cell identifiers which can
be seen in the range of your wifi networks. And its source code is available
(I originally found it on f-droid).

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shpx
thanks, installed.

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chrismcb
It would be cheaper, easier, and quicker to just do away with security theater
completely. Pesto, no wait time at all!

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lovemenot
A bit surprising that a sufficient proportion of people leave wifi and/or
bluetooth services on while at the airport, for this system to get a large
enough sample size.

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twblalock
Why would it be surprising? I only turn those off when I get on the plane.

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sehugg
I can't imagine that tracking cell phone emissions is the simplest way to
estimate the number of people in a line.

I also can't imagine this is the only thing they are doing/planning to do with
the data.

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schoen
Maybe more significantly, they aren't the only ones who are collecting this
data. A lot of retailers are doing it, and apparently some governments and
others are doing it too, all to keep track of people's whereabouts and habits.

There are also people who get in a position to map between a device MAC
address and an online identity. The easiest case is people who operate
hotspots that make people pay; there are also hotspots where you can
authenticate (sometimes optionally) with an account of the hotspot operator's
service, which may now include Facebook, not just mobile carriers.

In prior mobile OS versions -- at least -- some mobile apps were also directly
collecting the wifi MAC address and sending it back to the app developer.

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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.

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grecy
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"

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mandeepj
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.

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function_seven
> 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.

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ryguytilidie
I don't mean to get all tin foil hatish, but why on earth do they need things
like MAC addresses to count how many people are around? Is there not software
that could take video of the area and count these people? This just sounds
like an excuse to be overbearing...

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imroot
I'm wondering if the rapid decrease in the number of flights out of CVG might
have also caused the security waits -- since Delta left the Cincinnati airport
once the Northwest merger was approved, they keep on cutting flights back...

