What is SIM ? Why there is a cut on corner of the SIM card ?

What is SIM card? Why there is a cut on corner of the SIM card ?

ANSWER:

SIM card stands for Standard Identity Module card.

There are two competitive technologies for mobile phone GSM & CDMA.

1. GSM (Global Standard for Mobiles) technology mobile phones use SIM cards.

2. CDMA (Code Division Multiple Access) technology mobile phones use RUIM (Re-Usable Identity Module).

Among the above two technologies GSM is more widely used worldwide because of its advantages over CDMA.

Now coming to our topic,

SIM card is a removable electronic chip with embedded micro controller with some memory. SIM circuit is part of the function of universal integrated circuit code (UICC) which is usually made of PVC with embedded contacts and semiconductors.A SIM card contains its Unique Serial Number(ICCID) , International Mobile Subscriber Identity (IMSI) number which is used to identify the subscriber in mobile telephonic network.

SIM card & Mobile phone slot

Why there is cut on corner of the SIM card?

The reason for cut mark is to avoid the misalignment between SIM card chip and mobile phone cardholder pin contacts. Embedded chip of SIM card are designed in particular format, so pin contacts of SIM chip should make contact with the corresponding pin of the mobile phone. If not connected correctly SIM may not work, So cut mark serve as a guide for proper placement of card in SIM card slot of mobile phone.

SIM card come in 5 different sizes with standard dimensions shown in below image

SIM cards come with standard sizes