How does a smartphone SIM card work? The technology behind SIM cards explained

​Mobile phones need SIM cards to connect the user to the network of their choice.

A SIM – short for Subscriber Identity Module – is a piece of plastic that slots into your smartphone (or mobile phone) that acts as your unique ID, so that you can connect to, make calls over and be charged for using a particular mobile phone network.

Without a SIM card, you can’t connect to a mobile phone network, although for safety reasons, you can still dial 999.
When did SIMs first appear?

SIMs first appeared with the first digital ‘GSM’ mobile phones back in 1992. The Nokia 1011 was the first GSM mobile phone to go on sale. Unlike the analogue mobiles before it, GSM mobiles used digital technology for (relatively) interference-free communication — among other benefits.
Why do we use SIMs at all?

The SIM was part of a European telecommunications standard that separated mobile phones from the networks they connected to by moving all the necessary security and identification data onto a chip embedded into a removable piece of plastic the size of a credit card.
Since GSM technology also converted the voices at either end of a call into encrypted digital data before it was sent over the airwaves, the SIM also stored the ‘key’ (essentially a password) needed to decrypt this data.

(Visited 1 times, 1 visits today)

9 thoughts on “How does a smartphone SIM card work? The technology behind SIM cards explained

  • April 18, 2017 at 8:30 AM

    Thanks a lot for giving everyone a very marvellous opportunity to read from this blog. It really is very pleasant plus stuffed with fun for me personally and my office colleagues to search your blog a minimum of 3 times per week to learn the newest guidance you have. And of course, I’m actually satisfied for the striking things you serve. Some 2 facts in this post are really the finest we’ve ever had.

  • April 18, 2017 at 8:55 AM

    I wanted to develop a brief message to be able to thank you for these magnificent pointers you are writing on this site. My particularly long internet lookup has finally been recognized with reputable ideas to talk about with my friends. I would express that we site visitors are very much blessed to be in a fabulous site with very many perfect professionals with insightful secrets. I feel truly fortunate to have encountered the weblog and look forward to plenty of more pleasurable times reading here. Thanks a lot once more for all the details.

  • April 19, 2017 at 4:40 AM

    Thanks so much for giving everyone an extraordinarily breathtaking possiblity to check tips from this website. It’s usually so superb and stuffed with a great time for me and my office friends to visit your website not less than three times in a week to read the newest stuff you have. And lastly, I’m so at all times pleased with the attractive solutions served by you. Some 4 ideas in this posting are truly the best we have ever had.

  • April 19, 2017 at 2:44 PM

    Thank you for your entire work on this web site. My niece really loves carrying out investigations and it is easy to understand why. Almost all notice all of the compelling mode you deliver advantageous ideas by means of your blog and as well as welcome contribution from others about this situation and our princess is being taught a whole lot. Take pleasure in the remaining portion of the new year. Your performing a splendid job.

  • April 21, 2017 at 1:17 AM

    Needed to send you this little bit of note to finally thank you very much once again for those stunning tips you have featured above. It has been certainly incredibly generous with people like you in giving without restraint what some people could possibly have sold for an e-book to generate some money on their own, notably since you could have done it if you ever considered necessary. Those secrets also worked like the great way to realize that the rest have similar fervor just as my own to find out many more in respect of this condition. I’m certain there are many more pleasurable moments up front for folks who look into your site.

  • April 27, 2017 at 7:34 PM

    Thank you a lot for giving everyone an exceptionally wonderful chance to read in detail from this blog. It’s usually so beneficial plus stuffed with a good time for me personally and my office colleagues to visit your site really thrice in a week to study the new stuff you will have. And indeed, I am just usually impressed concerning the mind-boggling tricks served by you. Certain 2 ideas in this article are in reality the most efficient we have ever had.

  • Pingback: cheap jordan shoes

  • Pingback: longchamp handbags

  • Pingback: miami dolphins jerseys