AMPS

This technology is mentioned for historical purposes. Although radio phones or a proto cell phone technology can be traced back to the 1950s, Advanced Mobile Phone System (AMPS) is considered the first true cell phone network commercially available to the United States, starting in 1978.

AMPS communication was unencrypted, so people to listen in on cell phone conversations with an ordinary police scanner. Phones were often cloned, causing issues of fraud and network abuse. AMPS was also a bandwidth hog, using a Frequency-division multiple access (FDMA) scheme that required significant amounts of wireless spectrum.

AMPS started to get phased out beginning in the 1990s when PCS digital was introduced.

Verizon Wireless operated an AMPS network, and on February 18, 2008, Verizon discontinued all AMPS service. The last of the AT&T AMPS network was shut down February 18, 2008.