How SIM Cards Truly Work

A subscriber identity module or subscriber identification module. You most likely use it on daily basis, it’s all about your SIM card, that little chip in your phone. Do you know how it actually works? When, and by whom it was invented? Let’s check out.

When was it invented?

To start with, have you ever ever wondered what SIM stands for? It actually means (subscriber identity module or subscriber identification module).

In 1991, The primary SIM card was developed by a German firm Giesecke & Devrient. They sold 300 SIM cards to Radiolinja, a Finnish wireless network operator. In 1992, the corporate sold the first GSM mobile phone with a SIM card; it was a Nokia 1101.

At present, it’s practically inconceivable to search out a person who’s never used a SIM card — More than 7 billion gadgets world wide use them to make calls, ship SMS, and surf the web. Consultants predict this number is going to grow to 20 billion in the close to future.

The European Telecommunications StandardsInstitute (ETSI) still holds the foremost SIM patents, but other private phone firms even have some vital patents because of which SIMs work.

The biggest manufacturer of SIM cards on the earth is the Gemalto firm, with headquarters in Amsterdam and 15,000employees. They’re now working towards the mass production of SIMs for 5G networks. First SIM cards cost more than one greenback every to manufacture.

Right now, they’re basically worth just a few cents apiece. However that worth doesn’t cover design, development, inserting chips into plastic cards, and shipping them.

A SIM card has unique identification information on it, like what mobile network it belongs to. It’s called an IMSI -(Worldwide Mobile Subscriber Identity). This unique ID connects your phone number with your gadget. When somebody is dialing your number, the call will go to the precise phone you have got on the moment.

SIM also has its own memory. Although it’s really small — just 64 kilobytes — it can store around 250 contacts and a few SMS.

By the way, the identical memory was in the ApolloGuidance Computer used for the primary Moon landings.

In case your SIM card is mobile, which means you can remove it and put it back into your phone your self, you may also use it on different phones. This is useful when your own gadget’s battery is dead, and also you desperately have to make a phone call out of your number.

Can phone work without a SIM card?

Technically it can, as a camera, or a device that connects you to Wi-Fi, however not as a phone to make calls or text someone. For absolutely the majority of phones, a gadget without a SIM card is like a human without a brain.

The Good news is, even in case you severely damaged your phone — smashed your screen or bent the casing — you might still use the same phone number and keep your contacts. All it takes is a SIM card transplantation.

How does a SIM card work?

A SIM card basically looks like a little piece of plastic. It has a fair smaller chip inside that’s its Microcontroller. It’s made out of silicone and plated with gold or other metals to help it keep in touch with the phone.

SIM card carries a processor, memory, and security circuits. Our mobile system reads the chip whenever you insert the SIM in it.

It Incorporates the operating system for the card, can do some fundamental math, and stores vital information. This information is placed on the chip on the production line.

Probably the most basic types of that information are your International Mobile Subscriber Identity and a 128-bit key called Ki (Key Identification). Those are basically your login and password within the mobile phone world. All messages from our phone to the network are in a labeled code.

The key to encrypt and decrypt messages can be stored on the SIM card. This provides communication privacy. The SIM card chip also stores specific data, equivalent to your card’s unique serial number, the name of your mobile carrier, your PIN (for those who’ve ever wondered what it stands for, by the way, it’s your Personal Identification Number) to lock and unlock the phone, PUK code from the carrier to unblock the phone and far more. Even your contacts and last dialed numbers are there.

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