What does subid mean?

Subid of mobile phone is a program that records the times that a mobile phone inserts a SIM card.

The subid of the mobile phone is the increment of the primary key, and the value starts from 1. Every time a new card is inserted into the machine (if you can't see iccid, the value will increase by 1, and iccid is unique for each sim card). After inserting the dual card, two data entries with subid values of 1 and 2 will appear in the database.

No new entries will be added to the card slot database of card swapping, and only when a new sim card is inserted will a data item with id 3 be added. Subid, follow Ka. Subid is hard to understand. After Android5.0, google finally added the codes of multiple sim cards.

Before 5.0, the multi-card (usually dual-card) mechanism was written separately. The codes of mtk and Qualcomm have their own merits, but slotid is widely used, and subid is only used by mtk, rarely. After the unification of Google, subid is much more used than slotid.

Functions of SIM card:

SIM (Subscriber Identity Module) card is an IC card held by mobile users of GSM system, which is called subscriber identity card. GSM system identifies GSM users through SIM card. The same SIM card can be used on different mobile phones. GSM mobile phone can only be used in the network after inserting SIM card.

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.

Refer to the above? Baidu encyclopedia -sim card