When your mobile phone is switched on, your cellular network provider knows your exact location. Some mobile phone still sends signal to towers even when they are turned off.
Before you will start to build your own Mobile Number Locator, you must have an extensive knowledge of howMobile Phones,OperatorsandCell-sitesoperates to decide if you want to continue the implementation.To save you some time, below are some useful terminologies to keep in mind; MCC, MNC IMSI, CID, LAC.
Are often used in combination to identify a phone number’s operator in the mobile telephone network.
Mobile country code or MCC and mobile network code or MNC
The combination of MCC and MNC is called HNI or Home Network Identity
SIM card identifies with mobile network using the IMSI, which is made up of the MCC + MNC + IMSI or International Mobile Subscriber Identity.
Radio cells identify them selves with MCC+ MNC + Location Area Code + CellID
A Cell ID or CID) is a generally unique number used to identify each base transceiver station (BTS) or sector of a BTS within a location area code (LAC) .
LAC or Location Area Code is given an unique number within mobile network, the Location Area Code (LAC). This code is used as a unique reference for the location of a mobile subscriber.
There are many API that will return this information to your application upon providing a Mobile Phone number.
Let’s see how Mobile Phone Triangulation works.
Take a look at a cell tower below.
It shaped like a triangle. This is why:
Each side of the triangle is called a sector. These sectors are labelled by the Greek letters alpha, beta, and gamma (a, ß, Y). Within each sector, the tower can see how far away a connected cellphone is. Which allows it to “trace” the cell phone: by detecting which sector it is connected to, and how far away the cellphone is.
Above is a sample image of these sectors, with the cell phone tower being in the center.
We can assume that our target is connected to sector gamma, and is in the number 4 range. Then we know that the cellphone is somewhere in the by yellow marked area, see below image:
What happen when a cell phone connected to two towers?
When a cell phone is connected to 2 towers that overlap each other at the same time we can further increase our accuracy in tracing the phone.
For example, the cell phone is connected to the blue tower’s sector alpha and is at the 5’th band (5 miles) in distance, while it is also connected to the orange tower’s gamma sector and is in the 4’th band of distance (4 miles) of the orange tower, we can trace the cell phone really accurately by comparing the 2 results of the 2 towers, as shown below:
The Triangulation occurs when a 3rd tower is brought into action, we get what is called a “triangulation”. In this case, we can trace the cell phone accurately, as shown below:
Now, you can see, that the mobile phone is now within the red circle. If it moves to the left, it enters the green tower’s band 6. If it moves right, it enters the green tower’s band 4. If it moves down, it enters the green tower’s gamma sector and also enters band 4 of the blue tower.
When your mobile phone is switched on, your cellular network provider knows exactly where you are in the world.
Similar technology is used to track down lost aircraft and yachts through their radio beacons. It’s not identical, because most radio beacons use satellites while cell phones uses land-based aerial arrays, however the principle is similar.
whenever your phone is switched on, whether you’re using it or not, it sends out a check signal (heartbeat / beacons) to cell towers periodically which identifies location of the phone by the connected cell sites / towers.
Now, that we have a basic knowledge of how cell tower works, it’s possible to use an API to retrieve information of a mobile phone or device and connected cell ids, then compute the distances from those cell ids using the information returned by the API.
This may be accomplished by using the k-nearest neighbors algorithm + distance calculator.
Using the k-nearest neighbor algorithm to find the nearest neighbor of a point k (your phone number), then compute the distances between the indexes (cell ids) and the point k.Source : Techsload Baze