What Does It Really Take To Track A Million Cell Phones?
You can find anything and everything on the internet, yet nothing that explains how to track cell phones.
Let us clarify right away, we are not talking about how to track your own cell phone in case it’s lost or stolen. We are talking about tracking everyone that lives, breathes and wears a cell phone.
This is actually incredibly easy and we think that people should be aware of that.
If a representative of a phone service provider with 10 million customers came into my office and asked this question “What would it take to track every move of our 10 million customers?”. My answer would be “An intern and 6 months“. Then we’d insist the intern will need a desk, a computer, basic programming and algebra skills. That’s all it takes.
Imagine for a minute that you are the intern in question. Congratulations and welcome to our company! Your internship begins now, this document will introduce you to everything you need to know.
We’ll go over the basics of cellular networks, geolocation principles, technologies readily available in every cell phone and how to leverage all of that into a truly real-time planet-scale mass surveillance system.
Spoiler Alert: If you are scared of 1984 like scenarios, you may want to stop reading this and bounce to a video with Darth Vader playing the accordion.
We are in a unique position with cross domain expertise. We combine experience in state-of-the-art tracking systems with past experience in the telecommunication industry.
Whether it’s locating an item in a warehouse, guiding people inside a shopping mall or following stolen trucks. There are many legitimate use cases for tracking with as many constraints to satisfy: indoors, outdoors, with or without battery, variable precision, etc…
A phone itself comes with numerous technologies built-in: GPS, WiFi, accelerometer, compass, etc…
We’ll focus exclusively on what is needed to achieve easy, effective, reliable, mass-tracking.
We want to track cell phones. Which one? ALL OF THEM.
Better precision in time and position[1] is better but does not constitute a goal by itself. It has to be balanced against more important parameters like feasibility, scalability, reliability and costs of operation.
For the avoidance of doubt, we’ll call the project an utter success if we find ourselves able to pin point any cell phone being in a specific block inside a specific city, at a specific hour.
[1] A location is always a position AND a time together. It’s important to keep the two dimensions in mind.
Most systems work by “triangulation“. It’s possible to triangulate a specific position by comparing some measures to some points of reference. First things first, that’s actually called multilateration.
If you use a service like a GPS, it does all the work and gives out a position with a radius of error.
If you do the hard work yourself, either you are the guy making the GPS or you are trying to mix multiple sensors in a creative way, you need to do the hard work yourself.
Ultimately, it always comes down to 4 methods.
With information about the transmission power, the reception power and the medium. It’s possible to use physics wave propagation formulas to estimate the distance traveled.
In practice however, this method is extremely unreliable for radio waves, so you NEVER want to use that.
For instance, it’s typical for a long distance radio wave to go up and down 10 fold (+-10 dB) within a single second. It changes all the time and that’s when you are not moving. It gets worse when walls, windows and your head goes in and out of the track.
With the angle of a signal, it’s possible to determine that the source is within a line (or a cone). Obviously, it works better with highly directive signals.
You can surely picture a rotating radar like you’ve seen a thousand times in movies.
With the time and the speed of a signal, it’s easy to determine the distance. t = d/s.
Challenge: Radio waves travel at the speed of light 299 792 458 m/s.
