29-01-2013, 03:30 PM
INTRODUCTION TO 1G. 2G..3G 4G
INTRODUCTION TO 1G. 2G..3G 4G.pptx (Size: 1.26 MB / Downloads: 23)
1G WIRELESS TECHNOLOG
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.
DRAWBACKS OF
The GSM is a circuit switched , connection oriented technology, where the end systems are dedicated for the entire call session.
This causes inefficiency in usage of bandwidth and resources.The GSM enabled systems do not support high data rates. They are unable to handle complex data such as video.
Reduce range of sound.
Weaker digital signal.