2.3.1 First generation 1G:
1G, which stands for "first
generation," refers to the first generation of wireless telecommunication
technology, more popularly known as cell phones. A set of wireless standards
developed in the 1980's, 1G technology replaced 0G technology, which featured
mobile radio telephones and such technologies as Mobile Telephone System (MTS),
Advanced Mobile Telephone System (AMTS), Improved Mobile Telephone Service
(IMTS), and Push to Talk (PTT).
1G wireless networks used analog radio
signals. Through 1G, a voice call gets modulated to a higher frequency of about
150MHz and up as it is transmitted between radio towers. This is done using a
technique called Frequency-Division Multiple Access (FDMA).
In
terms of overall connection quality, 1G compares unfavorably to its successors.
It has low capacity, unreliable handoff, poor voice links, and no security at
all since voice calls were played back in radio towers, making these calls
susceptible to unwanted eavesdropping by third parties. However, 1G did
maintain a few advantages over 2G.
In comparison to 1G's analog signals, 2G's
digital signals are very reliant on location and proximity. If a 2G handset
made a call far away from a cell tower, the digital signal may not be strong
enough to reach it. While a call made from a 1G handset had generally poorer
quality than that of a 2G handset, it survived longer distances.
This
is due to the analog signal having a smooth curve compared to the digital signal,
which had a jagged, angular curve. As conditions worsen, the quality of a call
made from a 1G handset would gradually worsen, but a call made from a 2G
handset would fail completely.
Different
1G standards were used in various countries. Advanced Mobile Phone System
(AMPS) was a 1G standard used in the United States. Nordic Mobile Telephone
(NMT) was a 1G standard used in Nordic countries (Denmark, Finland, Iceland,
Norway and Sweden), as well as in its neighboring countries Switzerland and
Netherlands, Eastern Europe, and Russia.
Italy used a telecommunications system called
RTMI. In the United Kingdom, Total Access Communication System (TACS) was used.
France used Radiocom 2000.
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