SIM Full Form

SIM stands for Subscriber Identity Module, and it is an integrated circuit that keeps the international mobile subscriber identity in a safe manner (IMSI). It's a little memory chip that allows you to make phone calls wherever in the world that a subscriber's network is available. No phone can function without a SIM card, which might be considered the phone's heart. Multiple numbers per contact or other more complicated information cannot be stored on the SIM card. This implies that if you copy your contacts from your phone memory to your SIM memory, your contacts will be divided up into as many entries as there are numbers for each unique contact, and the rest of the information will be discarded.

In this article students will learn sim full form, working of sim, different types of sim cards used and sim long form.

SIM Card Full Form

SIM card full form is Subscriber Identity Module or it is Subscriber Identification Module. It is a smart memory card that allows us to make a phone call anywhere in the world as long as the user's contact network remains consistent.

SIM cards are commonly used on GSM networks that are operated and controlled by smartphones. It can be moved about and utilised with any mobile device that supports it.

History

Devrient and Munich smart-card manufacturers Giesecke created the first SIM card in 1991. The European Telecommunication Standards Institute was the first to acknowledge and proclaim the SIM. The invention of the SIM card allowed people all over the world to connect and interact with one another.

SIM Card Full Meaning

The full meaning of sim card is the subscriber identification module. It's a little memory chip that allows you to make phone calls anywhere in the world where the subscriber's network is active.

SIM Long Form is given below

• Subscriber= S

• Identity= I

• Module= M.

SIM cards are commonly found in GSM-enabled phones.

Every SIM is Unique

Subscriber Identification Module (Sim) has a piece of unique information associated with it, A phone number and your personal identification details are stored with every SIM connecting you with a network. You can use alternative browsing services if you don't have a SIM card in your phone, but you won't be able to make calls, text, or access the internet. The SIM card also has a lot of memory and can store up to 250 contacts, messages, and other vital data.

Types of SIM Card

There are two types of SIM  that are GSM and CDMA.

GSM:

GSM stands for Global System for Mobiles, and Bell Laboratories is credited with developing the technology in 1970. It operates in the 900 MHz, 800 MHz, and 1.8GHz bands and uses a circuit-switched mechanism that split each 200 kHz transmission into eight 25 kHz time slots. It employs a narrow band transmission method known as Time Division Access Multiplexing (TDAM). The data transfer rates range from 64 to 120 kilobits per second.

CDMA:

CDMA stands for code division multiple access, and it describes a communication channel theory that uses spread-spectrum technology and two different coding schemes: time-division multiplexing and frequency division multiplexing.

Standard, Micro, and Nano-SIM cards are the three most common sizes of SIM.

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Function of SIM Card

1) It Identifies the Subscriber: A subscriber's identity is determined by the IMSI code imprinted on the SIM card. To identify a subscriber, each IMSI is mapped to a mobile number and provisioned on the HLR.

2) Authenticate the Subscriber: This is a process in which each subscriber provides a unique response based on IMSI (stored on SIM) and RAND utilising the authentication method on the SIM card (provided by network). A lawful subscriber gets signed on to the network by matching this response with values computed on the network, and he or she can now access the mobile service provider's services. Mobile work is increasingly reliant on SIM cards.

3) Storage: To store phone numbers and SMS.

4) Applications: The SIM Tool Kit, also known as the GSM 11.14 standard, provides for the creation 

SIM-based applications that give basic demand information and other services

Applications for m-commerce, chatting, cell broadcast, phonebook backup,

Location-based services etc.

The List of Information Stored by SIM is

• Address details.

• Text messages.

• Personal security keys.

• Phone number.

• Data regarding network authorization.

• Other data.

The Following is a Collection of Some of the Most Important Data That SIM Carries.

• IMSI (International Mobile Subscriber Identity).

• Unique serial number.

• Security information.

• Brief details related to the local network.

Parts of SIM Card 

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Distinct circuit parts on a SIM card serve different purposes. The major components of a SIM are listed below.

• VCC (Power Supply)

• RST (Reset)

• CLK (Clock)

• D+ and D- (Optional USB Pad)

• GND (Ground)

• VPP (Voltage Programming Power)

• SIM Data I/O Pin

How Does a SIM Card works?

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The data that is stored in the SIM card includes a unique serial number called ICCID, International Mobile Subscriber Identity or IMSI, Security Authentication information, temporary information about the network, a Personal Identification Number or PIN. For GSM/CDMA, a SIM card's internal memory holds data, personal and financial information, and identity. Modern SIM cards support application data storage for use with the SIM application toolkit to interface with the device or server. To validate the identity of the subscriber in the network, the SIM card stores network-specific information. 

ICCID, IMSI, Authentication key or Ki, Local Area Identification or LAI, and an operator-specific emergency number are among the most significant keys among the many. Micro sim cards have been developed for use in the most recent mobile phones. Other information on the SIM includes the Short Message Service Centre number (SMSC), Service Provider Name (SPN), Service Dialing Number (SDN), Value Added Service (VAS), and so on. The SIM can store 250 contacts and has data capacities ranging from 32KB to 128KB.

Size of the SIM

When the SIM has first been produced in the beginning the size of the credit card, but the later size of the SIM eventually disclosed gives a capacity of 15 mm by 12 mm. Some cell phones now use nano and micro-SIM chips of different sizes.

A SIM card is required to operate all GSM phones and most iDEN phones.

Certain phones (CDMA, TDMA, and AMPS) do not require a SIM card. Instead, the necessary information is immediately loaded into the phone.

Replaceable SIM cards come in four standard sizes:

• Full-size (85.6mm × 53.98mm × 0.76 mm)

• Mini-SIM (25mm x 15mm x 0.76mm)

• Micro-SIM (15mm x 12mm x 0.76mm)

• Nano-SIM (12.3mm × 8.8mm × 0.67mm)

Microprocessor-Based SIM Cards:

The Microcontroller is the most critical component of the SIM card. It's a paper-sized chip with a typical ROM capacity ranging from 64 to 512 KB. The RAM size goes from 1 to 8 kilobytes, whereas the EEPROM capacity goes from 16 to 512 kilobytes. The card's OS, or operating system, is stored in the ROM, while personalization data, such as security keys, phone book, and SMS settings, are stored in the EEPROM. The working voltage of SIM may be 1.8V, 3V, or 5V, though the majority of modern SIMs support 5V, 3V, and 1.8V.

Conclusion:

From the above article, we have understood SIM card full meaning and how a sim card works. A SIM additionally stores information such as its unique serial number (ICCID), International Mobile Subscriber Identity (IMSI), security information, ciphering information, temporary network information, and so on.