Full form of SIM

Full form of SIM is the Subscriber Identification Module or Subscriber Identity Module.

It is a chip or integrated circuit which stores the International Mobile Subscriber Identity (IMSI) securely. It is a portable chip which allows the person to make phone calls or send messages around the world where network is available.

Usually the SIM is used in mobile phones which operate on GSM network. SIM is portable, so people can use it with any mobile devices.

History

In 1991, Munich Smart Card maker Giesecke and Devrient has made the first SIM card. The SIM was initially identified by the European Telecommunication Standards Institute.

The Size of SIM

The SIM was almost as the size of credit card when it was first invented. But as per newly invented standard, the size of SIM became lesser and it consists of 15mm by 12mm. And currently, the micro and nano SIM cards are available which used by some smart phones.

The information stores by SIM

SIM stores the information for GSM cellular phone subscribers. It also contains some of private as well as personal information of customers. The information stored by SIM is as follows,

• Text messages
• Address details
• Phone Number
• Network authorization data
• Personal security keys
• Other info.

SIM also contains,

• IMSI (International Mobile Subscriber Identity)
• Unique Serial Number
• Ciphering Information
• Security Information

Temporary Information related to local network etc.