Cancel the mobile phone card and refund the money?

Not refundable, but transferable. If there is a balance before the cancellation of the mobile phone number, the business personnel will ask you to leave him a local mobile phone number when the cancellation takes effect, and the balance can be transferred to other numbers in the province. After the cancellation number takes effect, the balance will be automatically transferred.

SIM card is the abbreviation of "SIM card", also known as subscriber identity card. Smart cards and GSM digital mobile phones can only use this card.

The information of digital mobile phone customers, encryption keys and user's phone book are all stored on the computer chip, which can be used for? GSM network? Identify customers and encrypt voice messages when customers call.

SIM card is mainly used in GSM network. W-CDMA network and? TD-SCDMA network, but compatible modules can also be used for IDEN mobile phones.

SIM card consists of CPU, ROM, RAM, EEPROM and I/O circuit. When users use SIM, in fact, the mobile phone sends commands to the SIM card, and the SIM card should be executed or rejected according to the standard specification; SIM card is not a simple information memory.

In the traditional SIM card usage scenario, people usually have to buy a mobile phone first, whether they are calling or texting or surfing the Internet with their mobile phones. Then go to the operator to handle the network access business, and then put the SIM card into the mobile phone.