UCSD Students Tracking Their Friends' Locations

An Anonymous Coward writes: "The location-tracking software, developed by a 15-year-old student at the university, draws upon triangulation technology. The PDAs figure out their locations by comparing the strength levels of signals traveling from the devices to various Wi-Fi antennas. No GPS Required. Article from Salon here..."

Comments

American University is going completely wireless

[Anonymous Coward]

Starting this fall, American University is going to have a completely wireless computer and phone network for all of it's students. Throw in a bit of gps, and hey, easy to track everyone everywhere! (Plus they get to add that fun new "set your phones to vibrate while in public rule!)

This is not *exacty* new.

[His name cannot be s]

There is a company Cell-loc that has been working on this same sort of thing, wireless location technology, without GPS.

I can certainly see that this sort of thing is going to get big, and a large number of companies are going to want it bad.

It's kinda neat stuff, and it nicely fits where GPS doesn't: Downtown. GPS requires line-of-site to the satelites, and without that you get no position. When you are downtown, amongst big buidlings, you can't find anything.

Asset tracking is going to be big too. Help! I lost my car/pet/wife/computer!

BUUUUUT!

I just can't see how that information is going to be private, I mean when the cops can simply get a warrent for the information, bam! instant confirmation of location. Privacy Agreement or not.

This has been around for years... Even for wavelan

[DeathB]

Carnegie Mellon University has had a wireless network for years now. A few years ago all of the academic buildings had full coverage, and in the past year this has been extended to dorms and most outdoor areas.

The computer science department at CMU as well as the Human Computer Interaction Institute (HCII) and the department of Electrical and Computer Engineering have been putting out papers on actual implementations of campus location systems. Most deal with its use for contextual/location aware computing (one of the more recent papers). Although some have dealt with the privacy implications (I should know, I was an author of one published at IEEE Wireless 2001). Project Aura deals with quite a bit of reasearch around what can be done positivly with this technology as well.

As one last thing, I wrote software to poll wavepoints and figure out a location over 1.5 years ago... It was less than 50 lines of C, so I have trouble being impressed by this.

Source code

[hiero]

The "ActiveCampus Locator" software for Jornadas and other platforms can be found at http://activecampus.ucsd.edu/locator.html.

There is even Linux source code there for "ActiveCampus-locator.cc", which has the description "Gets the access point list seen by the wireless card and sends it to the ActiveCampus server so it can geolocate for the user."

ATTWS offers the same thing

[Vegeta99]

Launching VERY soon, a new mMode service will allow you to locate your friends using the GSM e911 service (Enhanced Observed Time Difference). You can be "invisible", but thats I'll I know about it. TDMA customers are out of luck.

GPS uses triangulation

[stere0]

The GPS system calculates your position using GPS too! Here's a little bit about triangulation. I'm using GPS satellites because you get them for cheap in theory land and they come with these cool weightless levers. However you can replace them with 802.11 access points, cell phones, whatever suits you.

Imagine having three satellites on a chess board, the first one on a1, the second one on a8 and the third one on 1h. You're somewhere on the checkboard, and you know where the other satellites are. You know the speed of light is one square per second.

To find out where you are, you take out your brand new iBook and send five pings to the satellite in a8, using radio waves, which are light after all:

--- satellite-a8 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 14.00/14.00/14.00 s

Light takes fourteen seconds to go to the satellite and back. You now know you're anywhere in a seven squares radius from a8 and decide to ping the satellite in h1:

--- satellite-h1 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 14.00/14.00/14.00 s

You now know you're also seven squares away from the satellite in h1. You look at your map and understand that you can only be in a1 or h8. How do you find out? You ping the satellite in a1:

--- satellite-a1 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 22.00/22.00/22.00 s

Looking at this, it becomes clear that you are in h8. You can even use pythagoras to make sure I didn't get the distances wrong :). We use this method to locate any radio device, from the GPS in your car to your iBook.