Digital AMPS

What Does Digital AMPS Mean?

Digital AMPS (D-AMPS) is second-generation (2G) cellular technology meant as a further development over the North-American first generation system called AMPS (Advanced Mobile Phone Service). D-AMPS was widely used in the USA and Canada ever since the first commercial cellular network was first deployed in 1993. D-AMPS technology has been retired and largely replaced by GSM/GPRS and CDMA2000 cellular technologies.


Techopedia Explains Digital AMPS

Digital AMPS, IS-54 and IS-136 standards, uses time division multiple access channel access method and is usually referred to as a TDMA System or simply TDMA rather than the more appropriate D-AMPS. D-AMPS uses existing AMPS technology to safely and easily transition from analog to digital systems in the same area, allowing for a quick upgrade from AMPS, the original analog standard system for cellular communication in the US and Canada.

D-AMPS is the digital version of AMPS and provides TDMA (time division multiple access) to AMPS in order to get three channels for every single AMPS channel, therefore tripling the number of calls possible in a single channel, which obviously triples throughput.

Technical specifications:

  • 48.6 kbit/s channel bit rate
  • 1.62 bit/s/Hz
  • 40 ms frame duration which is divided into 6.67 ms slots
  • Each 6.67 ms slot contains 324bits and 260 user data
  • Differential QPSK
  • Vector Sum Excited Linear Prediction (VSELP)

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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.