What are the precautions when using uim card?

UIM card is used to access CDMA network of China Telecom, and it is the symbol of accessing network system. This card stores the data needed to access the network, so how much do you know about UIM card? The following is what I have compiled about uim card, I hope you like it!

The basic concept of uim card The storage capacity of UIM card

Generally speaking, the IC chip storage capacity of UIM card is 128KB, which can store the following information:

(1) 1000 telephone number and its corresponding name and characters.

(2) 40 groups of short messages.

(3) More than 5 groups of recently dialed numbers.

(4) 4-digit UIM card password (PIN).

There are 64k, 128k, 5 12k, 1m UIM cards in the market, as well as professional UIM cards that can provide multimedia services and contactless services. The capacity can reach m megabytes, but it is very few.

Password of UIM card

PIN code refers to the password of UIM card, which exists in UIM card and the factory value is 1234. After activating the PIN code, you must enter the PIN code every time you turn on the computer and log on to the network. PUK code is the master key used to solve PIN code, with ***8 digits. Users don't know the PUK code, and only the staff in the business hall can operate it. When the PIN code is entered incorrectly for three consecutive times, the UIM card will be locked automatically, and it can only be unlocked by entering PUK. PUK code * * * has 10 input opportunities. Therefore, at this time, the user must not touch his PUK password. After inputting 10 times incorrectly, the UIM card will automatically start the self-destruction program, making the UIM card invalid. At this point, only go to the business hall to change the card. In fact, as long as you use it carefully, the PIN password will only protect your safety.

The principle of UIM card

UIM card is a chip with a microprocessor.

There are five modules, each corresponding to a function:

CPU( 16-bit /32-bit), program memory ROM, working memory ram, data memory EEPROM and serial communication unit are integrated in an integrated circuit. When the SIM card is connected to the mobile phone, at least 5 cables are required:

* power supply (Vcc) * clock (CLK) * data I/O port (data) * reset (RST) * ground terminal (GND)

Uim card The internal structure of UIM card is a chip card with a microprocessor. It has five modules, each corresponding to a function: microprocessor CPU( 16/32 bits), program memory ROM (3 ~ 8kbit), working memory RAM (6 ~ 16kbit) and data memory EEPROM (16 kbit). These five modules are encapsulated in the copper interface of UIM card like ordinary IC card. These five modules must be integrated into an 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.

The power supply of UIM card is 5V compatible with 3V, 3V, and these cards must be used with corresponding mobile phones, that is, the power supply voltage of SIM card generated by mobile phones matches the voltage required by SIM card. After the SIM card is inserted into the mobile phone, the power port supplies power for each module in the UIM card.

The signal to detect the existence of UIM card is only generated at the moment of startup. If UIM card is not detected at startup, a prompt will be given. Insert UIM card? ; If the UIM card exists, but the communication between the machine and the card cannot be realized, it will display? Check UIM card? ; When the UIM card does not respond to the startup detection signal, the mobile phone will also prompt? Insert UIM card? ; When the UIM card falls out during the boot process, the contact is poor due to looseness, or the discarded card is used, the mobile phone will prompt "UIM card error? .

The storage capacity of UIM card is 64KB, 128K or even 1MB. Most of them are 16KB and 32KB. How many phone numbers and short messages UIM card can store depends on the capacity of EEPROM (2KB, 3KB and 8KB).

Precautions for using 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 cards must be stored in a dry and ventilated environment to avoid chip rust.

Instructions for using UIM card for the first time

When using UIM card for the first time, please follow the following steps:

(1) Turn off the power of the mobile phone;

(2) Refer to the user manual of the mobile phone and insert the UIM card into the correct position in the mobile phone;

(3) Turn on the power switch of the mobile phone, and after the network is connected, you can press the key to dial and make the first call.

UIM card is locked.

If the phone screen appears? The card is locked? Word, indicating that your SIM card has been locked. It may be that you entered the wrong PIN code three times in a row, which caused the card to be locked. In this case, please go to the local telecom business hall and the service staff will unlock it for you.

UIM card lost/stolen

When your UIM card is accidentally lost or stolen, for the sake of prudence, you should immediately go to the business hall of the local telecom or call 10000 (Telecom) to apply for reporting the loss, so as to prevent the UIM card from being stolen. After the UIM card is reported lost, you can apply to China Mobile or China Unicom for a replacement.

UIM card is damaged/faulty.

When the phone screen shows. UIM card error? This means that your UIM card is damaged and cannot be used. Please bring the original card to the mobile or Unicom business hall for replacement.

UIM card capacity

UIM card can store phone books and short messages, and the capacity is as follows: 64K phone book has 250 pieces and short messages have 40 pieces; Please refer to the mobile phone display for the specific memory of UIM card.

The type of card (UIM, mini UIM, Mick UIM) has nothing to do with the card capacity.