UMTS

UMTS is the third generation of mobile phones; this is what made governments all over Europe richer to the tune of billions of pounds through a series of auctions in 2000. Since there is only a limited bandwidth available in the 230MHz bands around the 2GHz frequency that is to be used (one for upstream and one for downstream), only a few companies could operate in them, so the UK government decided to auction off bandwidth in this range; a move that was emulated by other governments all over Europe.

UMTS is the European version of a proposal by the ITU called IMT-2000 (International Mobile Telecommunications 2000) and should be widely available by about 2005. In this system, the data rates that you can expect depend on the distance that you are from the base station of your cell. UMTS envisages a series of different sized cells that range in size from a picocell (with range of a home or office), through a microcell (about the size of a current GSM cell) to a macrocell (city sized or larger). These cells can be nested, so you can picocells inside microcells inside macrocells. The data rates that you can expect in a picocell are about 2Mbps, in a microcell 384Kbps and in a macrocell 144Kbps, which is a lot less than you could get in a picocell, but still much much faster than current GSM phones.

The major idea of UMTS is to have all areas of land covered by a macrocell, even in remote areas or up a mountain. GSM and UMTS operate in the very high frequency ranges around 900/1800MHz and 2GHz respectively, meaning that the radio waves have to be almost in line of sight of the transmitter (they don't bounce off the atmosphere like lower frequency radio waves do – if you want to know why, go find a physicist, or look up the Encyclopeadia Britannica or the Enquirer's guide to the universe, I've got no idea). This makes it difficult to have working mobile phones in remote or mountainous areas using terrestrial masts, so UMTS sets some of the bandwidth aside for integrated satellite access, giving the possibility for communication using a 3G (3rd generation) mobile phone no matter where you are, from the south pole to the Sahara; from Middlesex to Mongolia – a truly global communications network.


Introduction - Modems - ISDN - DSL - cable modems - Mobile comms - Conclusion - Glossary