Cell Phone Radiation :: Telephones Health Communication Essays

Cell Phone Radiation Introduction to Cell Phones Today, cell phones have become widely used among our society. However, there has been some customer concern of human safety concerning the use of cell phones. Cell phones are know to emit low levels of radiofrequency energy in the microwave range while in use and while in the standby mode, which leads to many ethical issues. History It is very interesting to note that a cell phone is actually a radio. However, it is an extremely sophisticated radio. Alexander Graham Bell invented the telephone in 1876. Wireless communication can be traced back to the invention of the radio by Nikolai Tesla in the 1880's, which was presented by an Italian, Guglielmo Marconi, in 1894. By combining these two technologies people have come up with the making of the cell phone. From the Dark Ages to Modern Times Before cell phones were invented, people installed radio telephones in their central antenna tower per city and about twenty-five channels were available on that tower. The central antenna needed a powerful transmitter, enough to transmit forty to fifty miles. There were not enough channels for many people to use radio telephones. However, the cellular system, which is the division of a city into small cells, has allowed millions of people to use cell phones simultaneously. In the United States, a typical analog cell phone carrier receives 832 frequencies to use across the city. The phone carrier breaks up the city into cells, which are usually about ten square miles. Each cell has a base station which has a tower and a small building that contains the radio equipment. One cell in an analog system uses one seventh of the available duplex channels. Each cell phone uses two frequencies per call, thus, making it a duplex device. A duplex device means that one frequency is for talking wh ile the other frequency is for listening and both people can talk at once. As for a simplex, such as a walkie talkie, two people communicate using the same frequency and only one person can talk at a time. In addition a walkie talkie usually has one channel while a cell phone can communicate on 1664 channels or more. Furthermore, a walkie talkie can transmit about one mile using a 0.25 Watt transmitter while a cell phone operates within cells, giving cell phones a wide range. How Does It Work? All cell phones have special codes associated with them, which are used to identify the phone, the phone's owner, and the service provider.