IMEI
International Mobile Equipment Identity. A unique serial number used on digital mobile phones.

IMT-2000
International Mobile Telecommunications-2000. The ITU’s concept of a ‘family’ of compatible third generation mobile technologies. UMTS is the European member of the IMT-2000 ‘family’.

ISDN
Integrated Services Digital Network. High quality fixed telephone line used primarily for data transfer between companies or for video conferencing.

ITU
International Telecommunications Union. Geneva-based organisation within which governments and the private sector co-ordinate global telecom networks and services.