1. By Emma Thompson Radio Communication

2. How it all started Marconi made the first radio transmission in 1895 100 years after this and 60% of the UK population (that’s 40 million people) now use a mobile phone.

3. What is a radio wave? Mobile phones and base stations both transmit and receive electromagnetic waves. Electromagnetic waves are emitted from lots of natural and man made sources, and we depend on electromagnetic waves from the sun to heat us. Radio, Television and mobile phones use electromagnetic waves to communicate.

4. How Radio communication works A radio frequency wave used in radio communication is called a carrier wave. This is produced by the transmitter as a sine wave. These waves carry little information, as so if more information needs to be added to these waves it is known as Modulation.

5. Amplitude Modulation Here is a diagram of how amplitude modulation works Here it can be seen that the amplitude is modulated to create more information being transmitted. Other types of modulation are also used, including frequency modulation (FM) and others such as digital techniques for mobile phones.

6. Mobile phone networks Mobile phones are linked to base stations. The mobile phone transmits Radio frequency signals to the nearest base station and then incoming signals are sent back from the base station to the mobile phone at a slightly different frequency. These base stations link the mobile phone to the phone’s network provider.

7. Base stations Every base station provides radio coverage in a hexagonal area known as a cell. As a person moves through the country the mobile phone connects to different base stations, depending on what cell they are in. The edges of the cell overlap each other so that network coverage isn’t lost when moving between cells.

8. References Roberts Radio (2007) (Online image) Available from http://www.lymington.com/robertsradio [Accessed 27/01/11] PUBLIC TELECOMMUNICATION NETWORKS UNIT (2001) How Mobile Phone Networks Work [WWW] Ofcom. Available from: http://www.sitefinder.ofcom.org.uk/mobilework.htm [Accessed 27/01/2011].