 USA NAMPS 10 kHz Narrow-band version of AMPS chiefly used in the USA and Israel based on a 10 kHz channel spacing. 25 kHz Analogue system originally in the UK. Based around 900 MHz, this system spread worldwide. After the system was first introduced, further channels were allocated to reduce congestion, in a standard known as Extended TACS or ETACS 12.5 kHz Nordic Mobile Telephone. This analogue system was the first system to be widely used commercially. Used initially on 450 MHz and later at 900 MHz. It was used chiefly in Scandinavia but it was adopted by up to 30 other countries. 200 kHz Originally called Groupe Spéciale Mobile, the initials later stood for Global System for Mobile communications. It was developed in Europe and first introduced in 1991. The service is normally based around 900 MHz although some 850 MHz allocations exist in the USA. DCS 1800 200 kHz 1800 MHz derivation of GSM and is also known as GSM 1800. PCS 1900 200 kHz 1900 MHz derivation of GSM and is also known as GSM 1900. 30 kHz US Digital Cellular. This system was introduced in 1991 and is sometimes called North America Digital Cellular - it is also known by its standard number IS-54 that was later updated to standard IS136. As it is based on a TDMA system it is often just called 'TDMA' in the countries where it is used. It is a 2G digital system that was designed to operate alongside the AMPS system. 200 kHz General Packet Radio Service. A data service that can be layered onto GSM. It uses packet switching instead of circuit switching to provide the required performance. Data rates of up to 115 kbps are attainable. 2.5/3G 200 kHz Enhanced Data rates for Global Evolution. The system uses a different form of modulation (8PSK) and packet switching which is overlaid on top of GSM to provide the enhanced performance. Systems using the EDGE system may also be known as EGPRS systems. cdmaOne 1.25 MHz This is the brand name for the system with the standard reference IS95. It was the first CDMA system to gain widespread use. The initial speci