Changes

[[Image:400px-Mobile phone evolution.jpg|right|thumb|Mobile phones ranging from a 1980s-era phone to a 2000s phone]]

[[Image:400px-Mobile phone evolution.jpg|right|thumb|Mobile phones ranging from a 1980s-era phone to a 2000s phone]]

A '''cellular telephone''' is a hand held device used for [[communication|communicating]], commonly known as a "cell phone" in the [[United States]], and also known as a "[[mobile phone]]" in [[Britain]], [[Ireland]] and [[Australia]].  In Germany they are known as 'Handies'

A '''cellular telephone''' is a hand held device used for [[communication|communicating]], commonly known as a "cell phone" in the [[United States]], and also known as a "[[mobile phone]]" in [[Britain]], [[Ireland]] and [[Australia]].  In Germany they are known as 'Handies'

==History==

==History==

The principle behind cell phones, transmitting waves modulated with sound signals (see methodology) was first seen in radio communications developed in the 1920s. However the potential of this [[Cellular technology|technology]] was not realised for many years, and the move towards the networks used today did not begin until 1947, when Bell Laboratory engineers Douglas Ring and Rae Young proposed using hexagonal grids with base towers at the corners (rather than in the centers) to allow communication. This creation of the "cellular concept" resulted in increased research into the possibility of evolving commonly used 2-way radio communication into real time speech.

The principle behind cell phones, transmitting waves modulated with sound signals (see methodology) was first seen in radio communications developed in the 1920s. However the potential of this [[Cellular technology|technology]] was not realised for many years, and the move towards the networks used today did not begin until 1947, when Bell Laboratory engineers Douglas Ring and Rae Young proposed using hexagonal grids with base towers at the corners (rather than in the centers) to allow communication. This creation of the "cellular concept" resulted in increased research into the possibility of evolving commonly used 2-way radio communication into real time speech.

==Safety Record==

==Safety Record==

There have been some studies which suggest cell phone might cause [[cancer]], especially in the [[brain]]. The [[World Health Organization]] was perhaps the first world-recognized organization to announce this possibility.<ref>http://www.cnn.com/2011/HEALTH/05/31/who.cell.phones/index.html</ref> At the very least, it is known that the radio waves from cell phones do effect the cells nearby, as is evidenced by the change in their [[metabolism]] rate of [[glucose]].<ref>http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet</ref>  However, no [[cell phone cancer]] link has ever been proven beyond doubt. (Also see: [[Mobile phones and brain tumor risk]]).

There have been some studies which suggest cell phone might cause [[cancer]], especially in the [[brain]]. The [[World Health Organization]] was perhaps the first world-recognized organization to announce this possibility.<ref>http://www.cnn.com/2011/HEALTH/05/31/who.cell.phones/index.html</ref> At the very least, it is known that the radio waves from cell phones do effect the cells nearby, as is evidenced by the change in their [[metabolism]] rate of [[glucose]].<ref>http://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet</ref>  However, no [[cell phone cancer]] link has ever been proven beyond doubt. (Also see: [[Mobile phones and brain tumor risk]]).

** [[Blackberry (phone)]]

** [[Blackberry (phone)]]

* [[Satellite phone]]

* [[Satellite phone]]

== External links ==

== External links ==

* [http://www.sri.com/policy/csted/reports/sandt/techin2/chp4.html SRI - The Cellular Telephone]

* [http://www.sri.com/policy/csted/reports/sandt/techin2/chp4.html SRI - The Cellular Telephone]

* [http://www.privateline.com/mt_cellbasics/ Privateline - The Cellular Telephone]

* [http://www.privateline.com/mt_cellbasics/ Privateline - The Cellular Telephone]

[[Category:Cell Phones]]

[[Category:Cell Phones]]