What numbers do I need to enter to activate the sim card number?

SIM card activation requires entering 20 digits, which is the unique identification number of SIM card.

But now you don't need to enter an activation code to activate the SIM card. Put the SIM card into the card slot and wait for a few seconds or even dozens of seconds before you can use it. SIM card is the key for GSM mobile phone to connect to GSM network. Once the SIM card is removed from the mobile phone, the mobile phone will not be able to enjoy all kinds of services provided by network operators except emergency calls.

SIM card can not only be used as a key, but also provide a lot of convenience for users. Users only need to insert or embed the SIM card into any GSM terminal to realize communication. SIM card also manages a lot of information provided to users, which can be used to store short messages, especially those received when users are away or absent.

relevant information

The logical structure of smart features of SIM card is a tree structure. All characteristic parameter information is expressed in the form of data fields. That is, there are three application directories under the root directory, one belongs to the administrative department and the other belongs to the technical management, that is, the GSM application directory and the telecom application directory.

All directories are data fields, as well as binary and formatted data fields. Some information in the data field is permanent, that is, it cannot be updated, while some information is temporary and needs to be updated. Each data field should express its purpose, update degree, characteristics of the data field (such as identifier), whether the type is binary or formatted, etc.