History of mobile phones

The history of mobile phones charts the development of devices which connect wirelessly to the public switched telephone network. The transmission of speech by radio has a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links. Hand-held radio transceivers have been available since the 1940s. Mobile telephones for automobiles became available from some telephone companies in the 1940s. Early devices were bulky and consumed high power and the network supported only a few simultaneous conversations. Modern cellular networks allow automatic and pervasive use of mobile phones for voice and data communications. In the United States, engineers from Bell Labs began work on a system to allow mobile users to place and receive telephone calls from automobiles, leading to the inauguration of mobile service on June 17, 1946 in St. Louis, Missouri. Shortly after, AT&T offered Mobile Telephone Service. A wide range of mostly incompatible mobile telephone services offered limited coverage area and only a few available channels in urban areas. The introduction of cellular technology, which allowed re-use of frequencies many times in small adjacent areas covered by relatively low powered transmitters, made widespread adoption of mobile telephones economically feasible. The advances in mobile telephony can be traced in successive generations from the early "0G" services like MTS and its successor Improved Mobile Telephone Service, to first generation (1G) analog cellular network, second g neration (2G) digital cellular networks, third generation (3G) broadband data services to the current state of the art, fourth generation (4G) native-IP networks. Pioneers of mobile telephony By 1930, telephone customers in the United States could be connected by radio to a passenger on an ocean liner in the Atlantic Ocean. The service was expensive, costing $7 per minute, equivalent to about $92.50/minute in 2011 dollars.[1] The first mobile telephone call was placed in St. Louis, Missouri on June 17, 1946 from a telephone set installed in an automobile. This first mobile telephone call was the end result of more than 10 years of work by Bell Labs scientists Alton Dickieson, D. Mitchell and H.I. Romnes.[2] Motorola and Bell Labs raced to be the first to produce a handheld mobile phone. That race ended on April 3, 1973 when Martin Cooper, a Motorola researcher and executive, made the first mobile telephone call from handheld subscriber equipment, placing a call to Dr. Joel S. Engel of Bell Labs.[3][4] The prototype handheld phone used by Dr. Martin Cooper weighed 2.5 pounds and measured 9 inches long, 5 inches deep and 1.75 inches wide. The prototype offered a talk time of just 30 minutes and took 10 hours to re-charge.[5] John F. Mitchell,[6][7][8] Motorola's chief of portable communication products and Martin Cooper's boss in 1973, played a key role in advancing the development of handheld mobile telephone equipment. Mitchell successfully pushed Motorola to develop wireless communication products that would be small enough to use anywhere and participated in the design of the cellular phone.[9][10]