What is UIM card?

UIM card is used to access the CDMA network of China Telecom, and it is the identification of accessing the network system. This card stores the data needed to access the network, such as UIM ID card, AKY value of authentication data, IMSI number, etc. UIM user identification module. It is a smart card applied to cdmaOne mobile phone, which can be inserted into the corresponding 2G mobile phone to use mobile phone services.

UIM card is a mobile communication terminal user identification and encryption technology advocated by China Telecom and supported by CDMA. It supports special authentication and encryption algorithms and OTA technology (over-the-air download), and can update and manage the data on the card through the wireless air interface.

The function of UIM card is similar to that of SIM card used in GSM mobile phone, which can be used for user identification and communication encryption, and can also store personal information of users such as phone numbers and short messages. At the same time, UIM card adopts the convenient use mode of SIM card and one card. Users only need to have a personal UIM card and insert it into any mobile phone with UIM card interface.

Internal structure: UIM card is a chip card with microprocessor. It has five modules, each corresponding to a function: microprocessor CPU( 16/32 bits), program memory ROM (3-8 kilobits), working memory RAM (6-16 kilobits) and data memory EEPROM( 128). These five modules are encapsulated in the copper interface of UIM card like ordinary IC card. These five modules must be integrated into the integrated circuit, otherwise their security will be threatened, because the connection between chips may become an important clue for illegal access and misappropriation of UIM cards.

Attention should be paid to when using smart UIM card:

1, do not bend the card, and the metal chip on the card should be carefully protected;

2. Keep the metal chip clean to avoid being polluted by dust and chemicals;

3. To protect the metal chip, please avoid pulling the UIM card out of the phone frequently;

4、? Do not place the UIM card in an environment above 85℃ or below -35℃;

5. Please turn off the power of the mobile phone before taking out or putting in the UIM card;

6. When the mobile phone has a low battery warning, please turn off the mobile phone and replace the battery.

7.UIM card must be stored in a dry and ventilated environment to avoid chip rust.