The evolution of mobile phones• The analog mobile phone system, 1G, voice-only service. The system is in this era, such as NMT, AMPS, DataTac started for the first time in 1980.• A digital cellular phone system 2G system that is in this era, such as GSM, PDC, cdmaOne, both voice and data. There is a switching circuit at 14.4 kbps-9.6 speed.• 2.5 G cellular system, a digital packet switching system that used. The system is in this era, such as GPRS speed 20-40 kbps.• 2.75 G systems that belong to this era, such as CDMA2000 1xRTT, EDGE, the speed is less than 10 kbps.• A digital cellular phone system 3G with the ability to reach both the voice and data communications, including video. The system is in this era, such as W-CDMA, TD-SCDMA, 1x-EVDO, more than 144 kbps speed CDMA2000.• 3.5 G cellular system, the digital with high data transmission speeds than 3G, such as HSDPA in W-CDMA.• The mobile phone system 4G Real-Digital can connect to a ground-3 data CDMA PA-H and connections and connection to Wi-Max ewifi images and sounds are of the same data.
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