Subscriber identity module. There are two different sizes used for GSM phone . one is the same size as a credit card and the other is about the size of a stamp. Both cards contains the same electronic circuits . it’s only the plastic surrounding it that differs. as well as subscription information, preferences and text messages. The SIM card is also called as RUIM card (RUIM - Removable User Identification Module). The use of SIM card is mandatory in the GSM world, whereas the SIM (RUIM) is not very popular in the CDMA world. |
