RUIM Cards and CDMA Gateways

What is RUIM Cards

Removable User Identity Module (R-UIM) is a card developed for CDMA handsets or CDMA gateways.By having a removable identity card, CDMA users can change phones while keeping their phone numbers by simply swapping the cards.This simplifies many situations such as phone upgrades, phone replacements due to damage, or using the same phone on a different provider's CDMA network.

The R-UIM card has been superseded by CSIM on UICC. This technique allows all three applications (SIM, CSIM, and USIM) to coexist on a single smartcard, allowing the card to be used in virtually any phone worldwide that supports smart cards.