The IMSI (International Mobile Subscriber Identity) is a unique 15-digit code used to identify an individual user on a GSM network.
The IMSI consists of three components:
- Mobile Country Code (MCC)
- Mobile Network Code (MNC)
- Mobile Subscriber Identity Number (MSIN)
Short for Public Land Mobile Network, a generic term for a mobile wireless network that is centrally operated and administrated by an organization and uses land-based radio frequency transmitters or base stations as network hubs. PLMNs can stand alone and interconnect with one another or connect to a fixed system such as the PSTN.
Cellular phones and mobile Internet access are two common uses of a PLMN.