hikapil said:
Cell phones operate on frequencies such as 850MHz, 900MHz, 1800MHz, and 1900MHz.
You are wrong at frequencies. I think the correct frequencies are 800, 900 and 1800 so:
A network infrastructure or wireless phone designed to operate in three frequency bands: 800 MHz, 900 MHz and 1800MHz.
I think you both are right
the frequencies depend on the phone and the place you are in
these are some phones with the frequencies matching :
Motorola V300 : GSM 850, 900, 1800, 1900
Siemens S56 : GSM 800, 1900
SE P910i :GSM 900/1800/1900