cell phone tower handoff

Thanks Daniel.

This is something Alexy worked on a few years ago.

Ironically, one of the authors, Blondel, is someone
that Valentino and I have crossed paths with in
other work we did in the mid-2000's regarding the joint
spectral radius.

Regards
George

On 3/27/13 11:10 AM, daniel wrote:
Hi George and John

I hope this email finds you well. Didn't one of your PhD students (with
an accent) explain to me like 2 years ago that he did this kind of work
- studying  cell phone handoff patterns is a great identifier of people

http://www.nature.com/srep/2013/130325/srep01376/full/srep01376.html


We study fifteen months of human mobility data for one and a half
million individuals and find that human mobility traces are highly
unique. In fact, in a dataset where the location of an individual is
specified hourly, and with a spatial resolution equal to that given by
the carrier's antennas, four spatio-temporal points are enough to
uniquely identify 95% of the individuals. We coarsen the data spatially
and temporally to find a formula for the uniqueness of human mobility
traces given their resolution and the available outside information.
This formula shows that the uniqueness of mobility traces decays
approximately as the 1/10 power of their resolution. Hence, even coarse
datasets provide little anonymity. These findings represent fundamental
constraints to an individual's privacy and have important implications
for the design of frameworks and institutions dedicated to protect the
privacy of individuals.

Daniel