18-01-2013, 01:48 PM
MOBILE TECHNOLOGY: EVOLUTION FROM 1G TO 4G
[attachment=47505]
First-generation (1G) mobile phones
had only voice facility. These were
replaced by second-generation (2G)
digital phones with added fax, data, and
messaging services. The third-generation
(3G) technology has added multimedia facilities
to 2G phones. And now talks are
on for the next-generation mobile technology
with more advanced features, i.e.
4G, which is expected to be available in
the market by 2010.
The theory of electromagnetic
radiation was propounded by Clark
Maxwell in 1857 and explained
mathematically the behaviour
of electromagnetic waves.
Then G. Marconi invented
trans-atlantic radio transmission
using electromagnetic
waves in 1901. However, as
the bandwidth of these transmission
systems was very small,
the transmission of information
was very slow.
Though the electromagnetic
waves were first discovered as a communications
medium at the end
of the 19th century, theses were put in
use for the masses very late. The
first systems offering mobile telephone
service (car phone) were introduced in
the late 1940s in the US and in
the early 1950s in Europe. These singlecell
systems were severely constrained
by restricted mobility, low capacity,
limited service, and poor speech
quality. Also the equipment was heavy,
bulky, expensive, and susceptible to interference.
The first generation
1G mobile phones were based on the analogue
system. The introduction of cellular
systems in the late 1970s was a quantum
leap in mobile communication, especially
in terms of capacity and mobility. Semiconductor
technology and microprocessors
made smaller, lighter, and more
sophisticated mobile systems a reality.
However, these 1G cellular systems
still transmitted only analogue
voice information.
The prominent ones among
1G systems were advanced
mobile phone system
(AMPS), Nordic mobile telephone
(NMT), and total access
communication system
(TACS). With the introduction
of 1G
phones, the mobile
market showed annual
growth rate of 30
to 50 per cent, rising to
nearly 20 million subscribers
by 1990.
The second generation
2G phones using global system for mobile
communications (GSM) were first used in
the early 1990s in Europe. GSM provides
voice and limited data services, and uses
digital modulation for improved audio
quality.
Multiple digital systems. The development
of 2G cellular systems was driven
by the need to improve transmission quality,
system capacity, and coverage. Further
advances in semiconductor technology
and microwave devices brought digital
transmission to mobile communications.
Speech transmission still dominates
the airways, but the demand for fax,
short message, and data transmission is
growing rapidly. Supplementary services
such as fraud prevention and encryption
of user data have become standard features,
comparable to those in fixed networks.
[attachment=47505]
First-generation (1G) mobile phones
had only voice facility. These were
replaced by second-generation (2G)
digital phones with added fax, data, and
messaging services. The third-generation
(3G) technology has added multimedia facilities
to 2G phones. And now talks are
on for the next-generation mobile technology
with more advanced features, i.e.
4G, which is expected to be available in
the market by 2010.
The theory of electromagnetic
radiation was propounded by Clark
Maxwell in 1857 and explained
mathematically the behaviour
of electromagnetic waves.
Then G. Marconi invented
trans-atlantic radio transmission
using electromagnetic
waves in 1901. However, as
the bandwidth of these transmission
systems was very small,
the transmission of information
was very slow.
Though the electromagnetic
waves were first discovered as a communications
medium at the end
of the 19th century, theses were put in
use for the masses very late. The
first systems offering mobile telephone
service (car phone) were introduced in
the late 1940s in the US and in
the early 1950s in Europe. These singlecell
systems were severely constrained
by restricted mobility, low capacity,
limited service, and poor speech
quality. Also the equipment was heavy,
bulky, expensive, and susceptible to interference.
The first generation
1G mobile phones were based on the analogue
system. The introduction of cellular
systems in the late 1970s was a quantum
leap in mobile communication, especially
in terms of capacity and mobility. Semiconductor
technology and microprocessors
made smaller, lighter, and more
sophisticated mobile systems a reality.
However, these 1G cellular systems
still transmitted only analogue
voice information.
The prominent ones among
1G systems were advanced
mobile phone system
(AMPS), Nordic mobile telephone
(NMT), and total access
communication system
(TACS). With the introduction
of 1G
phones, the mobile
market showed annual
growth rate of 30
to 50 per cent, rising to
nearly 20 million subscribers
by 1990.
The second generation
2G phones using global system for mobile
communications (GSM) were first used in
the early 1990s in Europe. GSM provides
voice and limited data services, and uses
digital modulation for improved audio
quality.
Multiple digital systems. The development
of 2G cellular systems was driven
by the need to improve transmission quality,
system capacity, and coverage. Further
advances in semiconductor technology
and microwave devices brought digital
transmission to mobile communications.
Speech transmission still dominates
the airways, but the demand for fax,
short message, and data transmission is
growing rapidly. Supplementary services
such as fraud prevention and encryption
of user data have become standard features,
comparable to those in fixed networks.