Radio frequencies used for cellular networks differ in ITU Regions (Americas, Europe, Africa and Asia).
The first commercial standard for mobile connection in the United States was AMPS, which was in the 800 MHz frequency band.
In Nordic countries of Europe, the first widespread automatic mobile network was based on the NMT-450 standard, which was in the 450 MHz band.
In the U.S., the analog AMPS standard that used the cellular band (800 MHz) was replaced by a number of digital systems.
In Russia and some other countries, local carriers received licenses for 450 MHz frequency to provide CDMA mobile coverage area.