History of mobile phones
The history of mobile phones covers mobile communication devices that connect wirelessly to the public switched telephone network. While the transmission of speech by signal has a long history, the first devices that were wireless, mobile, and also capable of connecting to the standard telephone network are much more recent. The first such devices were barely portable compared to today's compact hand-held devices, and their use was clumsy. Drastic changes have taken place in both the networking of wireless communication and the prevalence of its use, with smartphones becoming common globally and a growing proportion of Internet access now done via mobile broadband. Foundations Predecessors In 1908, Professor Albert Jahn and the Oakland Transcontinental Aerial Telephone and Power Company claimed to have developed a wireless telephone. They were accused of fraud and the charge was then dropped, but they do not really seem to have proceeded with production. In 1917 the Finnish inventor Eric Tigerstedt successfully filed a patent for a "pocket-size folding telephone with a very thin carbon microphone". Beginning in 1918, the German railroad system tested wireless telephony on military trains between Berlin and Zossen. In 1924 public trials started with telephone connection on trains between Berlin and