What are SIM Cards?

We all know what SIM cards are that is not the point of interest in this post but how do these petite yet powerful things work and what other tricks they have up their sleeve.

Radio Waves and GSM

We all know the spectrum and the radiations that are visible. there are some radiations which are invisible to the naked eye like, Radio Waves, Microwaves, Gamma Rays, X-Rays(Which by the way was a mistaken invention) and the like. SIM Cards use these radio waves to send and recieve transmissions. GSM phones were first created by Nokia, the Nokia 1101.

The largest manufacturing company in the world, The Gemalto Company holds the most amount of patents for the SIM Cards.

Cost of SIM Cards

Back then, these cards used to cost a little over a dollar, but now they don’t cost more than a few cents. These SIM Cards consist of the plastic card and the chip bounded by marketing and other costs which is not covered in the few cents of the production cost.

What does a SIM Card contain?

A SIM card contains Unique identification information, called the IMSI which stands for International Mobile Subscriber Identity.This ID is used to connect your phone number with your phone, which explains how you get a call to the gadget you are using right now. Most people are not familiar but it also contains a memory space of about 64 Kilobytes, which isn’t a great deal right now, but in terms of what a SIM card can hold, it is one. This memory can hold upto 250 contacts which is fair enough for such a less amount of space.

How does it work?

A SIM card also contains a chip which is a microcontroller. This chip contains a Processor, Memory and security circuits.Your phone has the necessary information to read the data on a SIM Chip.