2. Introduction Mobile phone have only recently been introduced in the world a form of communication. However, they stem from the use of radio communication which is a very old medium. The credit to the creator of radio is still of mixed opinion.
3. Tesla or Marconi Guglielmo Marconi is considered to be the creator of radio communication because he was the first person to create radio signal that crossed the Atlantic. Nikola Tesla could be considered to be the inventor of radio communication because he created and developed a way of wirelessly transmitting radio signals. Tesla Marconi
4. Radio waves Radio waves are a form of electromagnetic radiation that has wavelengths longer than infra red light within the electromagnetic spectrum. These are created naturally by lightning, this can also be created artificially for communication in both static and mobile forms.
5. Amplitude Modulation Radio frequency waves used for communication are called “carrier waves”. If speech is to involved in this communication it needs to be added to the carrier wave, this is called modulation. The amplitude is then varied in the wave to create the speech so that it sounds how it should.
6. Frequencies The advantage of radio waves Is that many things can operate on different frequencies with being interrupted. Radios uses frequencies around 180KHz to 1.6MHz Television uses frequencies around 470MHz to 854MHz Mobile phones use frequencies around 872MHz to 2170MHz
7. Mobile Phones Mobile Phones send and receive radio signals to one another by transmitting signals from phones to base stations. These base stations link all mobile phones and landline phones together. A very large number of base stations are need to handle all phone communication, this is due to a limited radio spectrum given to each mobile phone operator.
8. Cellular Radio areas. Base stations operate in a cellular structure, each base station has a limited range in which it can pick up mobile phones radio waves. Multiple base stations are placed in a cell structure so that radio signals can be picked up in as many places as possible.
9. References List of Radio Frequencies found at http://en.wikipedia.org/wiki/Radio_spectrum Image of Nikola Tesla and Guglielmo Marconi found at http://en.wikipedia.org/wiki/Invention_of_radio#Marconi Image of radio wave found at http://www.google.co.uk/images?hl=en&source=imghp&biw=1920&bih=887&q=radio+waves&gbv=2&aq=f&aqi=g10&aql=&oq= Image of amplitude modulation waves found at http://www.google.co.uk/images?hl=en&biw=1920&bih=887&gbv=2&tbs=isch%3A1&sa=1&q=amplitude+modulation&aq=1sx&aqi=g-s1g-sx9&aql=&oq=amplitute Image of base station found at http://commons.wikimedia.org/wiki/File:GSM_base_station_4.JPG Image of cell structure found at http://tap.gallaudet.edu/Presentations/SHHH2003LKS_files/TextMostly/Slide4.html
