Communication
is used to transfer  information between
sender and receiver which is of two types wired and wireless wire less
communication is also known as tele communication . As per the wire less technologies
we have various generations like 1G, 2G, 3G, 4G, 5g

1G  It  is
the first generation wireless  technology
which was started  in 1980, NMT(Nordic mobile
telephony),TACS(total access communication system)   ,ETACS(European
total access communication system) started wireless communication in  1G the speed was up to 2.4kbps ,it

Allows
voice calls in one country  analog
signals are preffered in this generation As analog signals canot be transferred
to a long distance made raise to new generation 2G

2G
second generation  uses digital
technology in which analog signals are converted to digital and vise versa
which can cover up a long distance.GSM is the technology is introduced for
wireless voice communication for data accesss we went to 2.5G technology data speed
was up to 64kbps It provides services like text and picture messages. 2.5G in this  technology gprs is introduced for data
transmission but data rate is low(56.64kbps) hence we moved to 2.75G2.75G  EDGE(enhanced data rate for gsm technology)
developed here data rate is 170kbps 2G,2.5G,2.75G combindly known as 2G technology

3G:
(UMTS)  universal mobile terrestrial
system which gives data rate of 384kbps which also provide us videos calling
this increased bandwidth and introduced web applications It provides faster
communication in sending and receving messages .cost is the major draw back and
it increased phone size

4G:
1gbps data rate for stationery users and 100mbps for high

Mobility users we need higher data rate when we move in bullet train sNow
our target is 5G (10gbps ), it includes features like  high speed data access and high quality streaming
video , it combind stuff of wi-fi and wi-max, more