Where's that Phone?: Geolocating IP Addresses on 3G Networks

Where's that Phone?: Geolocating IP Addresses on 3G Networks, Mahesh Balakrishnan, Iqbal Mohomed, Venugopalan Ramasubramanian, in Proc. of SIGCOMM Internet Measurement Conference'09, November 2009.

I was looking at the program for IMC'09 and this paper caught my interest. It is a very basic experimental study which shows that:

for a given mobile device, the IP address assigned by the operator (in most cases, AT&T wireless) is not static, but changes a lot over time. This creates issues (or opportunities) for IP-filtered web sites.

for a given IP address, the location of the device cannot be predicted: the same IP address could be assigned at different times to device in wildly different locations. This has implications, in particular for the service which hopes to translate the IP address into location-based advertising.

the delay information is the best predictor for location: there is correlation in the application delay and the location of the device.

Those are quite interesting results to keep in mind, as the number of mobile devices connected to the Internet through 3G is increasing rapidly. So it is a really cute observation.