A subscriber identity module or subscriber identification module. You most likely use it every single day, it’s all about your SIM card, that little chip in your phone. Do you know how it really works? When, and by whom it was invented? Let’s check out.
When was it invented?
Initially, have you ever wondered what SIM stands for? It really means (subscriber identity module or subscriber identification module).
In 1991, The first SIM card was developed by a German company Giesecke & Devrient. They sold 300 SIM cards to Radiolinja, a Finnish wireless network operator. In 1992, the company sold the primary GSM mobile phone with a SIM card; it was a Nokia 1101.
Right this moment, it’s practically inconceivable to search out an individual who’s never used a SIM card — More than 7 billion gadgets around the world use them to make calls, send SMS, and surf the web. Consultants predict this number goes to develop to 20 billion within the close to future.
The European Telecommunications StandardsInstitute (ETSI) still holds the foremost SIM patents, but different private phone firms even have some necessary patents because of which SIMs work.
The largest manufacturer of SIM cards in the world 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 price more than one dollar every to manufacture.
Right this moment, they’re basically price a few cents apiece. But that value doesn’t cover design, development, inserting chips into plastic cards, and shipping them.
A SIM card has distinctive 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 someone is dialing your number, the call will go to the precise phone you have got at the moment.
SIM additionally has its own memory. Although it’s really small — just sixty four kilobytes — it can store round 250 contacts and some SMS.
By the way, the same memory was within the ApolloGuidance Computer used for the first Moon landings.
In case your SIM card is mobile, that means you’ll be able to remove it and put it back into your phone yourself, you can also use it on completely different phones. This comes in handy when your own gadget’s battery is dead, and also you desperately have to make a phone call from your number.
Can phone work without a SIM card?
Technically it can, as a camera, or a tool that connects you to Wi-Fi, but not as a phone to make calls or text someone. For absolutely the mainity of phones, a gadget without a SIM card is like a human without a brain.
The Good news is, even for those who significantly damaged your phone — smashed your screen or bent the casing — you possibly can still use the identical 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 is its Microcontroller. It’s made out of silicone and plated with gold or other metals to assist it keep in contact with the phone.
SIM card carries a processor, memory, and security circuits. Our mobile machine reads the chip while you insert the SIM in it.
It Comprises the operating system for the card, can do some basic math, and stores important information. This information is put on the chip on the production line.
Probably the most basic types of that information are your Worldwide Mobile Subscriber Identity and a 128-bit key called Ki (Key Identification). These are basically your login and password in the mobile phone world. All messages from our phone to the network are in a categorised code.
The key to encrypt and decrypt messages is also stored on the SIM card. This provides communication privacy. The SIM card chip additionally stores specific data, comparable to your card’s unique serial number, the name of your cellular provider, your PIN (in the event you’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 final dialed numbers are there.
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