Universal integrated circuit card
The universal integrated circuit card (UICC) is the smart card (integrated circuit card) used in mobile terminals in 2G (GSM) , 3G (UMTS), 4G (LTE), and 5G networks. The UICC ensures the integrity and security of all kinds of personal data, and it typically holds a few hundred kilobytes. The official definition for UICC is found in ETSI TR 102 216, where it is defined as a "smart card that conforms to the specifications written and maintained by the ETSI Smart Card Platform project". In addition, the definition has a note that states that "UICC is neither an abbreviation nor an acronym". NIST SP 800-101 Rev. 1 and NIST Computer Security Resource Center Glossary state that, "A UICC may be referred to as a SIM, USIM, RUIM or CSIM, and is used interchangeably with those terms", though this is an over-simplification. The primary component of a UICC is a SIM card.