- Europe Bands
- 900 MHz
- 1800 MHz
- American Bands
- 850 MHz
- 1900 MHz
- this global variation, caused mobile phones to operate at multiple frequencies
- problem: there is not one standard for cellular communication
Cellular Network Types
- 2.0G
- 2.5G
- 3.0G
- 4.0G
- 5.0G