N AMPS

N AMPS is a narrowband version of AMPs - which in turn is one of the first cellular analog systems.

The original AMPs system was similar to FM radio and allowed 30 KHz of frequency space for each cellular phone call.  Each call would be on a different center frequency to keep them apart, and each call was allotted 30 KHz bandwidth of space for voice information.

After cellular was in operation for awhile, its large capacity that had seemed endless at the start was now reaching its limits.  More customers wished to be on the airwaves but the system could not handle it.  One way to allow more customers on was to use the current analog system and just allow each call a little bit less bandwidth.  In the case of AMPs, the new system was called NAMPs - or narrowband AMPS and allowed each phone conversation just 10KHZ of bandwidth instead of 30 KHz each.  This allowed three times as many customers on the cellular airwaves.  The tradeoff for this was less high frequencies that could be used for cellular conversations.  However, the quality of NAMPs seemed quite good - at least for voice conversations.

As more and more customers wished to be on the airwaves, digital systems were invented such as iDEN, GSM, TDMA, PDC, and CDMA and similar ones that could allow more cellular conversations at the same time.  Also regulating bodies such as the FCC in the US opened up more frequency bands for the new digital cellular systems.  Those bands included 1.5 GHz (Japan), 1.8 GHz ( Worldwide), and 1.9 GHz (US PCS) among others.  This additional frequency allocation also allowed more customers to use cellular.