A SIM is a widely used card inside mobiles. It is almost omnipresent in all mobiles. The full form of SIM is:
S- Subscriber
I – Identification
M – Module
It stores the International mobile subscriber identification number inside it for secure use for users. The SIM can store several contact information of various people from several countries. Today, it is possible for people who reside in different countries to call each other just because of the International data roaming feature.
Types of SIM Cards
There was an earlier 2G network only, then slowly the 3G network was inducted. Now 4G network is used extensively and 5G network is being slowly introduced in several countries. There are several types of phones based on what type of SIM they support. 2G supporting phones are also called GSM phones, the phones which support 3G network are called GSM phones, and the phones which support 4G network are called LTE phones. A new variant of 4G which is called VoLTE is mostly being used as it gives the feature of voice over the network.
Unique Feature
A SIM card is a very personal asset that has very private codes and information. A SIM card possesses a unique ID which is given for security purposes. The IMSI number is also of very high importance and it stands for international mobile subscriber identity. Each country has a unique code number which is attached in front of the phone number. There are towers which respond to the SIM and then a call is made. A network tower has different receivers established by different network companies. A SIM can be tracked down as it uses the connectivity feature which is linked to satellite and mobile tower.
History of SIM Card
A SIM card dates back to 1960 when an integrated chip card was developed. A silicon IC chip is the base model for a SIM. Mobile phones are extensively used nowadays as more than 7 billion mobile devices are being connected over the world. SIMs in huge number have been manufactured lately and a 2016 figure reveals that 5.4 billion SIM cards were produced which generated more than $6.5 billion.
Availability and Designs
Acquiring a SIM card is not difficult at all, like it used to be two three decades back. A SIM requires personal details and some official papers for registration purposes. In India, it is mandatory for citizens to give their finger print to get a SIM of several mobile network companies. The SIMs differ in size and shape as there are different type of SIM trays and slots. There are mobiles which have the capacity to hold only one SIM. The dual SIM mobiles have SIM trays which can accommodate two SIMs and there are mobiles who can even accommodate more than two. But the standard is a dual SIM mobile which are the most used SIMs.
Types of SIMs
The SIM trays can differ in size too and there are some SIMs which aren’t physically required. These SIMs are called e-SIMs and they are the latest addition into the types of SIMs. There are standard SIMs, micro SIMs and Nano SIMs which are arranged from big to small.