GPRS
General Packet Radio Service. Data communications upgrade for GSM networks, enabling a maximum data rate of up to 115kbps. All UK networks are aiming to adopt this system by early 2001.

GSM
Global System for Mobile Communications. A digital cellular communications standard used throughout Europe, and elsewhere around the world. The standard is used in three frequency bands – 900MHz, 1800MHz, and 1900MHz. In the UK, the term GSM is commonly used to mean GSM900 – while GSM1800 networks are often referred to as PCNs.

GSM900
GSM network operating in the 900MHz band – as used by BT Cellnet and Vodafone in the UK, and by more than 100 countries around the world.

GSM1800
GSM network operating in the 1800MHz band – as used by Orange and One 2 One in the UK, and by a small but growing number of countries around the world.

GSM1900
GSM network operating in the 1900 MHz band – as used in several states in the USA plus parts of Canada and South America.