Most people know that they cannot operate their mobile phones and smartphones without a SIM card inside of them. These small chips come in a few different shapes and sizes. To the layman, they seem to have embedded data that allows us to connect to our host networks.
But, have you ever wondered why we need to use SIM cards in our cell phones? And just what are they, apart from being gold-colored chips? Today’s article gives you an insight into how something so small helps us communicate with the world around us.
How do cell phones work?
Some of you will know that mobile phones work over radio waves. They “talk” to radio masts in your local area. In fact, there are thousands of these masts all over the country. As you travel from one “cell” area to another, you don’t lose signal as long as you’re in a zone with a transmitter.
In essence, it works in a similar way to the radio in your car. Does your local radio station send transmissions over a large area? If so, the signal it sends out gets fed through several regional transmitters.
Except with cell phones, your handset can send data as well. That data could be your voice in a phone conversation. It could be a text message. Or it could even be “packet” data when you use your smartphone’s web browser, for example.
Why are SIM cards needed?
With me so far? Good! Now, we know that many cell phones need a small chip called a SIM card to work. But, have you ever wondered why some mobiles don’t need a SIM card? The answer is down to the type of network they use.
GSM networks, which power many of the world’s cell phone networks, need a SIM card. CDMA networks, like those utilized in the United States, don’t usually need one. Now, you might be wondering why we need SIM cards at all. After all, can’t we all just use CDMA networks?
With SIM cards, you can use any device to connect to the network as long as the device works with that network. Some people use “unlocked” phones for this purpose. That means you can change your mobile phone to a newer model and still use the same SIM card with it.
That’s a problem with CDMA networks because you’re restricted to the one phone.
Who makes these SIM cards?
Some people assume that the mobile networks themselves make the SIM cards. In fact, other companies manufacture the SIM cards for them! For example, Workz SIM card manufacturers provide the cards for Middle-Eastern network operators.
What happens if we lose our SIM cards?
The good thing about SIM cards is that they can get replaced. If your phone gets lost or stolen, the mobile network can deactivate the old SIM card and activate your subscriber details on a new one.
And because mobile networks have such a high stock of SIM cards, you will usually not get charged for a replacement.