AMPS:
Advanced Mobile Phone Service (AMPS) is a first-generation analog,
circuit-switched cellular phone network. Originally operating in the 800 MHz
band,
service was later expanded to include transmissions in the 1900 MHz band,
the VHF range in which most wireless carriers operate. Because AMPS uses
analog signals, it cannot transmit digital signals and cannot transport
data packets without assistance from newer technologies such as TDMA and CDMA.