06-02-2012, 02:49 PM
1G ,2G , 3G and 4G
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1G WIRELESS TECHNOLOGY
.Using Analog signals
.Listen to handset
. Frequency typically 150MHz & above
DRAWBACKS OF 1G
.Poor voice quality
.Poor battery life
. Large phone size
.No security
.Frequent call drops
. Limited capacity and poor handoff
reliability.
SECOND GENERATION
2G phones using global system for mobile communications (GSM) were first used in the early 1990 s in Europe. GSM provides voice and limited data services and uses digital modulation for improved audio quality. Digital AMPS , CDMA were some of the 2G systems.