AMPS (EIA/TIA-553) and NAMPS (IS-91)?

AMPS AMPS (Advanced Mobile Phone Service) was the first cellular mobile system in the United States. AMPS operates as an analog system using 30 kHz wide channels. NAMPS AMPS was later enhanced to NAMPS (Narrowband Advanced Mobile Phone Service), a version of AMPS that uses 10 kHz channels and by doing so triples cellular capacity. AMPS by Any Other Name Europeans often refer to AMPS as "American Mobile Phone Service." Digital cellular equipment manufacturers and carriers often refer to AMPS as "Analog Mobile Phone Service." AMPS Standards AMPS is defined in the EIA/TIA-553 standards. NAMPS is defined in the TIA/EIA/IS-91 standard. AMPS Network Operators AT&T Wireless operates a NAMPS network in the United States.