Infrastructure in London
Electric power supply
Several power stations were built to generate electricity in the centre of London, including the famous power stations at Bankside and Battersea (both now disused). Bankside power station has now been converted into Tate Modern, but still houses part of a large electricity transformer substation. A unique element of the London power grid is that it was the first urban high voltage direct current transmission system in the world. It was subsequently converted to standard 3-phase alternating current.
The Thames Water Ring Main supplies much of London with water. Sewage disposal was historically a problem, causing major pollution of the River Thames and potable water supplies. London suffered from major outbreaks of cholera and typhus well into the mid-19th century. Indeed, the problem was so severe that Parliament was suspended on occasion due to the stench from the river. These problems were solved when Sir Joseph Bazalgette completed his system of intercepting mains to divert sewage from the Thames to outfalls east of London, where the tide would sweep the sewage out to sea.
There are 188 telephone exchanges in London and all offer ADSL internet services. Most of London, and some adjacent places, are covered by the 020 area code. Some parts of outer London are covered by the 01322, 01689, 01708, 01895, 01923 and 01959 codes. There is extensive wireless LAN coverage, especially in central London such as the City of London Corporation, who are developing blanket coverage for the financial district. There is wide coverage from five mobile phone networks of which four are GSM/UMTS and one is UMTS-only.
Most analogue and digital television and radio channels are received throughout the London area from either the Crystal Palace Transmitter or Croydon Transmitter in south London. Cable television is widespread with service provided by Virgin Media, however coverage is not universal. TalkTalk TV provide an expanding video on demand cable television service over ADSL to the London area. Broadband internet and telephone services are also provided by the cable television networks.
With computers and technology playing a key part in the economy, companies have created a large number of datacentres within Greater London, many of which are in the Docklands area. As a result, London now hosts key parts of the Internet, including LINX (London INternet eXchange), the largest Internet Exchange Point in the world, carrying over 846 Gbit/s of Internet traffic (as of July 2012).