SIM CARD – What does it do and what function does it perform in the phone?


Probably many times you have wondered what the SIM card really is. Most of us are aware of the fact that it is impossible to make calls without it. A large part knows that you can save at least some of your contacts. However, how is it possible that such a small “device” is able to allow us, for example, to make calls?

What was it created for?

The SIM (Subscriber Identity Module) is a short sized portable device with a processor and internal memory. Its function is primarily to connect the subscriber of the network with the operator. This card identifies us in the network and with the help of the phone gives us the opportunity to connect with other users. At this point, it must be noted that without a SIM card you can also make calls. It is possible, however, only for emergency numbers such as, inter alia, 112. This solution allows us to respond in cases in which we need emergency help and our phone has blocked the ability to make calls or for some reason does not have a SIM card. Calls to emergency numbers are also priority for network transmitters, so that even in the case of high load of this network, we are kind of privileged to connect to the help center.

Other functions of the card

As I mentioned earlier, the SIM card also has a built-in memory. It is very small but allows us to record a certain number of contacts. The SIM card also plays an additional role in the operators’ systems. Each of them has the option of imposing a simlock on a given phone so that it works only with the card detected as the card of the given operator. In Poland, however, this solution is currently being abandoned, and most of the devices sold on the market do not have a blockade any more. However, if your phone still has a simlock – do not worry, you’ll take it off at a good price with us!

SIM card standards

The SIM card, as in principle, every part of the GSM system is evolving. The full-size full card, which was also the precursor of the current cards, had the size of a credit card. However, the dimensions of the card changed over time. In the vast majority of keyboards, the MiniSIM card was the standard. Later, when the market began to dominate smartphones, the size of the card was even more evolved and decreased to the size of micro and nano sim. With these card standards, the Sim installation on the phone often uses special trays in which we have to place the card before inserting it into the phone. At this point, it should be added that older cards can be exchanged with the operator for new ones or cut to the appropriate size. In our points it is possible to reduce the card to the standard that supports your phone. We guarantee trouble-free operation after such treatment!

Dual SIM – two numbers in one phone

With the development of mobile telephony, phone manufacturers have decided to introduce the possibility of handling two cards at the same time. Currently, a large part of devices sold on the market already has such a solution. These types of phones are additionally marked and sold as “dual sim” versions. The “dual sim” solution is also offered in several variants.

The first is the active mode. Phones that have both card inputs in active mode allow simultaneous operation of two cards at the same time. It also allows two separate antennas installed in the phone. The standby mode also allows us to operate two cards, while one of them becomes inactive when we use the second one. This solution is the most popular of the currently used. The last solution is the passive mode where the switching between the cards is done manually and we have to decide which one is active at the moment.

So how could you find out from the above text, the SIM card plays an important role in our phone. Without it, we can not use the phone in accordance with its original purpose. The lack of a SIM card prevents us from using cellular data, but above all it does not allow us to make calls and send and receive text and multimedia messages. That’s why it’s so important to have an efficient card entry in your phone. In case of damage, but also if your card is in the wrong size, please contact us. We will help you in restoring your phone to the usable state and the card will match your phone :)!