USIM (Universal Subscriber Identity Module)
Updated
The USIM is the application on a SIM card that authenticates the subscriber on 3G, 4G and 5G networks. It stores the IMSI, the secret key and network lists such as preferred and forbidden networks. Its files and functions are defined in 3GPP TS 31.102.
In practice
When people talk about the files of a SIM (forbidden networks, preferred networks, the IMSI), they usually mean the files of the USIM, which many modules can read with the AT command AT+CRSM.
Reference
Related terms
- UICC (Universal Integrated Circuit Card)
- IMSI (International Mobile Subscriber Identity)
- Forbidden PLMN list (FPLMN)
- AT commands