4G communication

while going on to 4G u may get doubt about the G so.....

G?? is the generation of of mobile services

The 4G comm is MIMO(multiple input and multiple output) which can attain a data rate up to 20–40 mbit/s

why 4G

It is all about spectrum. Marconi pioneered the wireless industry 100 years ago.
Today life does not seem possible without wireless in some form or the other. In
fact wireless permeates every aspect of our lives. The demands on bandwidth and
spectral availability are endless. Currently wireless finds its widest expression in
fixed and mobile roles. In the fixed role, wireless is used extensively for data
transfer, especially from desktop computers and laptops. In the mobile role, wireless
networks provide mobility for use from fast vehicles for both voice and data.
Consequently wireless designers face an uphill task of limited availability of radio
frequency spectrum and complex time varying problems in the wireless channel,
such as fading and multipath, as well as meeting the demand for high data rates.
Simultaneously, there is an urgent need for better quality of service (QoS), compared
with that obtainable from DSL and cable.