a relatively small part of the international bandwidth. Broadcast transmission Most broadcasting organisations, BBC and commercial, lease transmission facilities from one or more of the transmission companies. The main exception is the smaller local radio stations, some of which find it more cost-effective to provide their own. Fixed phone lines BT is still the main provider of fixed telephones lines, both POTS and ISDN, and it has a universal service obligation, although companies can now contract Openreach to install a phoneline on their behalf, rather than telling the customer to get BT to install it, then transfer over. Virgin Media is the second biggest player in the residential telephone line market. Other companies provide fixed telephone lines too, but mainly to large companies in the major cities. There are many other providers who sell fixed telephone services carried over BT lines. They have no network infrastructure of their own. Mobile phone networks Timeline First generation networks Cellnet was originally jointly owned by British Telecom and Securicor. BT eventually bought out Securicor's stake. The network became BT Cellnet and was then demerged to become O2. Vodafone Both companies ran ETACS analogue mobile phone networks. First and second generation networks O2 - runs a GSM-900 network, owned by Telefónica. Vodafone - runs a GSM-900 network. EE - runs a GSM-1800 network. Formerly this was two separate companies: Orange and T-Mobile, which was originally called One-2-One. Third generation networks The four 2G companies all won 3G licences in a competitive auction, as did new entrant known as Hutchison 3G, which branded its network as 3. They have now rolled out their networks. Hutchison 3G does not operate a 2G network, previously having agreements with Orange and O2 to allow roaming on their 2G networks. The third generation stems from technological improvements and is in essence an improvement of the available bandwidth, enabling new services to be provided to customers. Such services include streaming of live radio or video, video calls and live TV. Fourth generation networks Long-term evolution (LTE) services are currently being rolled out. EE launched their 4G network in October 2012, using part of their existing 1800 MHz spectrum. O2 and Vodafone will use the 800 MHz band with Vodafone also using the 2600 MHz band for their services. O2 launched its 4G network on 29 August 2013, initially in London, Leeds and Bradford with a further 13 cities added by