Glossary

1. MCC

   Mobile Country Code

   Code assigned to a each country in order to identify the country a mobile user belongs to. More info here.
2. MMI

   Man Machine Interface
3. MNC

   Mobile Network Code

   2 digit-code assigned to a mobile operator in every country. It helps, combined with the MCC identifying uniquely the mobile operator. More info here.
4. USSD

   Unstructured Supplementary Service Data

   Protocol used by mobile operators to implement a real-time communication with a phone user, via phone prompts.