Phones

The phone is a portable telephone that can make and receive calls through a radiofrequency carrier, while the user is moving within a telephone service area. In the early stages of radio engineering, a mobile handheld radio service was conceived. In 1917, Finnish inventor Eric Tigerstedt filed a patent for a pocket-sized folding phone with a very thin carbon microphone. The first predecessors of cell phones include analog radio communications of ships and trains.

The race to create portable telephone devices really began after the Second World War, with the evolution taking place in many countries. The advances of mobile telephony have been traced in successive generations, starting with the 0G services, such as the Bell Mobile Service of Sistemas de Bell and its successor, the Enhanced Mobile Telephony Service. These 0G systems were not cellular, they supported some simultaneous calls, and they were very expensive.

The first handheld cell phone was introduced by Motorola in 1973. The first commercial automated cellular network was launched in Japan by Nippon Telegraph and Telephone in 1979. This was followed in 1981 by the simultaneous launch of the Nordic Mobile Telephony system in Denmark, Finland , Norway and Sweden.10 Many other countries continued to apply in the first half of the 1980s.

All cell phones have a variety of characteristics in common, but manufacturers seek product differentiation by adding features to attract consumers. This competition has led to a great innovation in cell phone development in the last 20 years. Low-end mobile phones are generally referred to as feature phones, and offer basic telephony services. Terminals with more advanced computing capability through the use of native software applications are known as smartphones.

Several series of phones have been introduced to address specific market segments, such as RIMBlackBerry focusing on the email needs of corporate / business customers, the Sony-Ericsson 'Walkman' music / mobile series and 'Cyber-series'. shot 'of camera / phone, the Nokia Nseries of multimedia phones, the Palm Pre, the HTC Dream and the Apple iPhone.