AMPS used Frequency Division Multiple Access (FDMA) which enabled each cell site to transmit on different frequencies, allowing many cell sites to be built near each other.

AMPS also had many disadvantages, as well. Primarily, it did not have the ability to support the ever-increasing demand for mobile communication usage. Each cell site did not have much capacity for carrying higher numbers of calls. AMPS also had a poor security system which allowed people to steal a phone's