Full Form of SIM

What is a SIM?

SIM or Subscriber Identification Module is a portable chip, a built-in circuit that stores the international mobile subscriber identity (IMSI) in a strong, safe way. A SIM is like a smart memory card that allows us to establish a phone call across the globe where the contact network of the user is constant.

A subscriber identification module is used on smartphone-operated and controlled GSM networks. A SIM card is movable and it can be used on any mobile device that supports this.

Invented in 1991 by Devrient and Munich smart-card maker Giesecke, the SIM was initially recognized and declared by the European Telecommunication Standards Institute.

Functions of SIM Card

A lot of information is stored in the SIM card as it brings essential pieces of data back and forth to the network of customers and holds some of their private and personal data as well. This is the list of information that is stored in the SIM:

• Personal security keys
• Phone number
• Text messages
• Address details
• Data regarding network authorization.
• Other data.

Crucial data carried by the SIM:

• Unique serial number
• Security information
• IMSI (International Mobile Subscriber Identity)
• Brief details related to the local network.

SIM Card: Size

In its initial days, when SIM was first produced it was nearly the size of a credit card. But, with time, the size of the SIM eventually disclosed gives a capacity of 15 mm by 12 mm. Today, smartphones use distinct sizes of nano and micro-SIM chips.