1G - Mobile voice
First-Generation Analog
Advanced Mobile Phone Service (AMPS).
In North America, two 25-MHz bands allocated to AMPS.
One for transmission from base to mobile unit.
One for transmission from mobile unit to base.
Each band split in two to encourage competition.
Frequency reuse exploited.
Characterization
Most popular 1G system during 1980s
Advanced Mobile Phone System (AMPS).
Nordic Mobile Phone System (NMTS).
Total Access Communication System (TACS).
European Total Access Communication System (ETACS).
Key features (technology) of 1G system
Frequency 800 MHz and 900 MHz.
Bandwidth: 10 MHz (666 duplex channels with bandwidth of 30 KHz).
Technology: Analogue switching.
Modulation: Frequency Modulation (FM).
Mode of service: voice only.
Access technique: Frequency Division Multiple Access (FDMA).
Disadvantages of 1G system
Poor voice quality due to interference.
Poor battery life.
Large sized mobile phones (not convenient to carry).
Less security (calls could be decoded using an FM demodulator).
Limited number of users and cell coverage.
Roaming was not possible between similar systems.
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