T-Mobile UK

By sergioxii in UK (gsm) 0 Comment

 

T-Mobile UK was previously known as One 2 One, and before that as Mercury One 2 One. One 2 One was in its final days operated as a joint venture between Cable and Wireless and American cable provider Mediaone Group, which had a number of investments in Britain dating back to its days as the US West Media Group. One 2 One was the world’s first GSM 1800 network when it launched in September 1993. T-Mobile offers both pay-as-you-go and pay-monthly contract phones. The pay-monthly contracts are branded as Flext for both 18 month and 12 month contract customers as of February 2007; T-Mobile’s 12 month contracts were previously branded as Relax. The network also offers other contract options for off-peak users and customers who call within network predominantly. T-Mobile launched their 3G UMTS services in the Autumn of 2003.
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O2 UK

By sergioxii in UK (gsm) 0 Comment

Other know names

BT Cellnet – United Kingdom
Cellnet
BT Cellnet

Originally launched in 1985 and trading as Cellnet, Telecom Securicor Cellular Radio Limited was a joint venture between BT Group (then called British Telecommunications) (60%) and Securicor (40%). In 1993 it launched GSM services in UK, and its analogue eTACS service was discontinued in 2000 as part of changes to the regulation of spectrum in the UK. In 1999 Securicor sold its remaining shares to BT and the company was renamed BT Cellnet and became a part of the BT Wireless family of companies within BT.

After demerger from BT in 2001, BT Cellnet became O2 UK, a subsidiary of mmO2 plc.

This subsidiary of Telefónica Europe is currently named Telefónica O2 UK.

Out of all the major UK network operators, Telefónica O2 UK has the largest number of subscribers.

Brief description of GSM standard

By sergioxii in Theory (gsm) 0 Comment

GSM is Short for Global System for Mobile Communications, one of the leading digital cellular systems. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency. GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the de facto standard in Europe and Asia.

Considered the most advanced digital cellular technology, GSM networks are leaders in many typically "digital" services including the Short Message Service (SMS), Over the air (OTA) configuration and GSM positioning. Considering its technology and presence both in Americas and the rest of the world, GSM is in a good position for global roaming and many new GSM phones are called "global phones", since they can be used in virtually any country. The SIM card ("Subscriber Identification Module") is also a unique and essential component of GSM phones. Technically, GSM was built based on the TDMA protocol.