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Mobile devices
 

Mobile devices

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    Mobile devices Mobile devices Presentation Transcript

    • mobile devices History & Future
    • history
      • It can be said that the mobile devices was born at the same time the radio communication had been invented.
      • The development of mobile devices starts from the 1920's, there are five stages.
    • Stage One
      • 1920's-1940's
      • Based on several wave bands of shortwave, the private mobile communication system had been invented.
      • The Detroit police car radio system is the representative one.
      • The frequency of this system is 2MHz at that time. In the 1940's the frequency had been risen to 30~40MHz.
      • It is considered as the beginning of the modern mobile service.
    • Stage Two
      • 1940's-1960's
      • The public mobile service came out.
      • 1946 According to the plan of Federal Communications Commission(FCC) the Bell system established the first public car phone net in St.Louis.
      • There was three channles in that time, the mode was simplex.
    • Stage Three
      • 1960's-1970's
      • America improved the mobile telephony system(1MTS)
      • This period complete :
      • automatic channel choose
      • automatic dialing to the net
    • Stage Four
      • 1970's-1980's( the peak time)
      • The Bell Labs successfully developed the advanced mobile phone system(AMPS)
      • The cellular network built up, improved the capacity of the system.
      • The cellular network becames the utility system, used in the worldwide.
    • Stage Four
      • Achivements in this stage:
      • microelectronic technique got a significant development which made the probability of miniaturization mobile devices be true.
      • The new system of mobile communication----cellular network
      • provide the technique for the manage and control of the large size net
    • Stage Five
      • 1980's-
      • The Digital Mobile Communication System(DMCS) gets developed and mature in this period.
      • AMPS & TACS stand for the Cellular Networks Ⅰ->analog system
    • Future
      • The mobile devices plays an indispensable role in nowaday's life, meanwhile this field is still rapidly developing. More app is going to be added into.
      • In 2004 July 16, Japanese telephone company NTT DoCoMo announced the P605iC phone which carried the FeliCa soft. This phone opened the curtain of No Cards Generation.
    • Future
      • Nowadays the manufactures of mobile devices are devoting on touching screen and 3D effect.
      • More and more APP will be added into the mobile devices, make people's life much more convenient and fun.