Can I use Japanese sim card for my mobile phone in China?

China mobile phone can use Japanese sim card, and only supports Unicom 3 and 4G terminals.

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.

Main contents of SIM card:

SIM card is a kind of "smart" card which conforms to the GSM specification. It contains information related to users and is stored in the client, including? .

1, International Mobile Subscriber Identification Number (IMSl). Simply put, it is the phone number of the user. IMSI is the only global code number that can identify users. It uses the network to identify which country, which telecom business department or even which mobile service area users belong to. .

2. User key and security algorithm. The user key and security algorithm can not only identify the user's identity and prevent illegal access to the network, but also prevent the data transmitted by the user on the wireless channel from being stolen, thus eliminating the phenomenon of "unauthorized number merging"? .

3. Personal password (PIN code) and SIM card unlocking password (PUK code). PIN code is the personal password of SIM card, which can prevent others from using SIM card without authorization. When the PIN code is pressed incorrectly, the PUK code needs to be unlocked.

4. Storage space used by users. Users can store some personal information in the SIM card, such as fixed short messages and directories.