How does the mobile phone identify the operator of the SIM card| Love to play computer games - 上海419贵族宝贝-上海后花园1314-上海品茶网-阿拉爱上海

After the SIM card is inserted, the phone will automatically identify which operator you are, and then display the name of the operator on the phone screen. This is something we are used to, but some people may ask, the same SIM card also looks similar. Why can't my Unicom card use China Telecom's network? How do they identify which operator the SIM card belongs to?

In fact, there is an IMSI identification code inside our SIM card, which stores the country and operator of the SIM card.

The Chinese name of IMSI is International Mobile Subscriber Identity, which is the key to identify mobile phone users. The total length of IMSI is no more than 15 digits, using numbers from 0 to 9. IMSI consists of MCC+MNC+MSIN.

MCC (Mobile Country Code) is the code of the country where the mobile phone number belongs, accounting for 3 digits. The resources of MCC are uniformly allocated and managed by ITU, and the MCC in China is 460. With MCC, you can distinguish which country the user comes from, so you can realize international roaming.

In addition, there are usually multiple carriers in a country. Which carrier signal do you want to use for your mobile phone? At this time, it depends on MNC to judge. MNC generally consists of two digits: 00, 02, 07 for China Mobile, 01 for China Unicom, and 03 for China Telecom.

MSIN (Mobile Subscriber Identification Number) is used to identify the mobile number in a mobile communication network.

For example, for the IMSI 460017500428184, its MCC is 460, representing China. MNC is 01, representing China Unicom, so this is a SIM card from China, and the telecom operator is China Unicom.