In the early days of mobile telephony, the various systems used throughout the world were incompatible with one another which was expensive and caused communication problems. There has since been a massive growth in mobile telephone systems worldwide and a system was needed to resolve communication issues. A group formed in Europe in the early 1980s called Groupe Special Mobile (GSM ) with the aim of developing a system that could be used throughout Europe.
GSM is now the Global System for Mobile Communications which is an international digital technology for transmitting mobile voice and data services including SMS (Short Message Service) which operates on the 900MHz and 1800MHz bands in Europe and the 1900MHz and 850MHz bands in the US. The 850MHz band is also used for GSM and 3G in Australia, Canada and some South American countries. Most global mobile phone markets uses the GSM standard in over 218 countries.
Using GSM architecture and GSM roaming, people can use their phones while travelling and can make use of the same services abroad as they can at home by switching carriers using the same phone. You can find out if your phone will work on a particular network or in a particular country by checking www.gsmworld.com/roaming/gsminfo/
GSM phones work as broadly as possible in over 200 countries over four different frequencies: 850 MHz, 900 MHz, 1800 MHz and 1900 MHz. The main GSM networks in the UK are Cable and Wireless UK (GSM 1800 technology), FMS Solutions (GSM 1800), Mundio Mobile Limited (GSM 1800), Orange PCS Ltd (GSM 1800), T-Mobile (UK) Limited (GSM 1800), Telefonica O2 UK Limited (GSM 900/1800), TeleWare PLC (GSM 1800), Vodafone Ltd (GSM 900/1800).
Mobile phones operate over three frequency bands: Dual Band (900MHz and 1800 MHz), Tri-Band (900 MHz, 1800MHz and 1900 MHz) and Quad Band (850 MHz, 900 MHz, 1800 MHz and 1900 MHz). The 3rd Generation or 3G standard enables simultaneous use of speech and data services and higher data rates and delivers multimedia applications using greater bandwiths. Users can therefore connect to the internet very securely at the highest possible speeds. The main 3G networks in the UK using 3G 2100 technology are Hutchison 3G UK, Orange PCS, T-Mobile UK, Telefonica O2 UK and Vodafone.
All mobile phone have a SIM card which is a Subscriber Identity Module card. It identifies the user and stores text messages, phone logs and contact details. A SIM free phone has no SIM card which mneans any network provider can be used with an existing SIM card. This provides more freedom and flexibility because you are not tied to a particular network. Flying Penguin offers mobile phone deals including unlocked, SIM free mobile phone products – you can check the latest deals at www.flying-penguin.co.uk.