TETRA number structure and Mobile Country Codes
The full International TETRA Subscriber Identity (ITSI) consists of Mobile Country Code (MCC) + Mobile Network Code (MNC) + Short Subscriber Identity (SSI). The SSI is sufficient to identify a subscriber within one network (SwMI) only. Whenever there is interaction between a subscriber mobile terminal and a SwMI other than the home network, the full ITSI is needed for unique identification of the terminal. Typically this interaction is related to roaming or traffic between networks.
The MCC field has a length of 10 bits giving a decimal range of 0 to 1023. The allocation of MCC’s and the table associating them with their countries is now managed by the International Telecommunications Union (ITU) and the information can be found from the following link to the ITU-T Recommendation E.218 at the ITU web site.