What is the full form of SIM?

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

SIM is generally used on smartphone-operated and controlled GSM networks. It is movable and can be used by a user with any mobile device that supports this.

History

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

Function of SIM Card

SIM card stores a lot of information and also brings essential pieces of data back and forth to the network of customers and holds some of their private and personal data as well. The list of information stored by SIM is

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

A few crucial data carried by SIM are listed below.

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

Size of The SIM

When SIM was first produced in the beginning the size of nearly the credit card, but the later size of the SIM eventually disclosed gives a capacity of 15 mm by 12 mm. Some smartphones now use distinct sizes of nano and micro -SIM chips.