SIM Full Form?

While the entire world uses SIM cards, not many may actually know the full form of SIM

Mobile phones have become an integral part of our lives. One of the key components powering the wireless technology is the SIM card. It may seem like a simple piece of plastic, but there is a lot going on inside the SIM and related systems. Let us find out the details.

What is SIM full form?

SIM full form is Subscriber Identity Module. What our eyes see as a small piece of plastic with metallic traces is actually a very tiny computer. A SIM card functions like a digital ID card for a mobile network. There are many things you can do with a mobile phone like taking pictures, recording video, accessing video and audio content, browsing the web via Wi-Fi network, etc. However, for calling and sending SMS and using mobile data, you will need a SIM card.

A SIM card works by storing data in encrypted format. As is evident from the SIM full form, Subscriber Identity Module, the encrypted data is used by the telecom operator to identify the user. When you insert a SIM into a phone, the SIM sends a unique code to the network. This establishes the identity and makes a secure connection with the network. Since the data shared is in encrypted format, it cannot be accessed by a third-party.

It is difficult to hack a SIM card since modern day SIM cards use 128-bit encryption for calls and text messages. A SIM card also ensures portability, allowing you to switch to another phone without having to change the SIM.

What is the information stored inside a SIM card?

A SIM card stores a wide variety of information. For example, it stores a unique 15-digit IMSI (International Mobile Subscriber Identity). This is unique to not just your country, but also unique to the global network. Another number one can see on the SIM card is the ICCID (Integrated Circuit Card Identifier). This is a unique serial number of the SIM card, usually printed on the back of the SIM card.

Other important information stored on a SIM card is PIN and PUK code. PIN is the code that people can set to protect their SIM card from being misused. When a phone gets stolen, both the phone and the SIM card can be misused. Even if you have secured your phone with a PIN, password, face lock or fingerprint lock, the SIM can be removed and used with another phone.

To protect the SIM, you need to set a separate PIN for the SIM card. This way, your SIM cannot be used with another phone unless the correct PIN is entered. And if 3 wrong PIN codes are entered, the SIM card will be locked. You will then need a PUK (Personal Unblocking Key) code to unlock it. This is something that you can request from the telecom provider. SIM cards also store contact and SMS messages. They have a small memory of around 64KB to 256KB.

What is eSIM?

The eSIM full form is essentially the same as the SIM full form, with just the addition of ‘e’ (embedded) as a prefix. So eSIM is essentially Embedded SIM. eSIM is a chip that is soldered directly onto the smartphone’s motherboard. It is digitally programmed and cannot be removed by everyday users.

Instead of a physical SIM, the eSIM supported phones store the information digitally. Multiple eSIM profiles can be created, which is useful for folks who frequently travel to other countries. However, at a given time, typically only one or two eSIM profiles can be actively used. When the user travels to a different country, they can switch on the eSIM of that location. Hope the above information helped you understand the SIM full form and the related systems.