AMPS - Advanced Mobile Phone Service

CDPD - Cellular Digital Packet Data

CDMA - Code Division Multiple Access

CSMA - Carrier-Sense Multiple Access

CT0 - Cordless Telephone 0

CT1/CT1+ - Cordless Telephone 1

CT2/CT2+ - Cordless Telephone 2

DBSPK - Differential Binary Phase-Shift Keying

DCS 1800 - Digital Communication System

DECT - Digital European Cordless Telephone (Telecommunications)

DSSS - Direct Sequence/Spread Spectrum

DQPSK - Differential Quadrature Phase-Shift Keying

ETACS - Extended Total-Access Communication Systems

FDD - Frequency Division Duplex

FDM - Frequency Division Multiplexer

FDMA - Frequency Division Multiple Access

FHSS - Frequency Hopping Spread Spectrum

FM - Frequency Modulation

FSK - Frequency Shift Keying

GFSK - Gaussain Frequency-Shifting Keying

GMSK - Gaussian Minimum-Shift Keying

GSM - Global Standard for Mobile

JCT - Japanese Cordless Telephone

LAN - Local-Area Network

NADC - North American Digital Cellular

NTAC - Narrowband Total-Access Communication System

OQPSK - Orthagonal (Offset) Quadrature Phase-Shift Keying

PACS - Personal Advanced Communications Systems

PCS - Personal Communication Service

PDC - Personal Digital Cellular  (Cordless)

PHS - Personal Handy Phone System

QPSK - Quadrature Phase-Shift Keying

RX - Receiver

TACS - Total Access Communication System

TDMA - Time Division Multiple Access

TX - Transmitter

WAN - Wide Area Network



AMPS, Advanced Mobile Phone Service

The term used by AT&T’s Bell Laboratories to refer to its cellular technology.  The AMPS standard has been the foundation for the industry in the United States, although it has been slightly modified in recent years.  “AMPS-compatible” means equipment designed to work with most cellular telephones1.

CDPD, Cellular Digital Packet Data

As the cellular phone enabled millions of mobile professionals to stay in touch with the office via voice communication, CDPD promises to give customers a reliable, relatively fast way to send and receive digital data communications such as fax, credit card verifications, fleet management data, emergency services, messaging service, and e-mail.  Although CDPD can be allied to all of the world’s cellular systems, the largest system is North American advanced mobile phone system (AMPS)1.

CDMA, Code Division Multiple Access

A modulation which independently codes data in multiple channels for transmission over a single wideband communication link.  It may be used as an access method that permits carriers from different stations to use the same transmission equipment by using a wider bandwidth that the individual carriers otherwise require.  Upon reception, each carrier is distinguished from the others by means of a specific modulation code.  This enables reception of signals that were originally overlapping in frequency and time. 

CDMA allows several transmissions to occur simultaneously within the same bandwidth.  But the mutual interference (RFI) is reduced by the degree of orthogonality of the unique codes used in each transmission.  This also permits a more uniform distribution of radiated energy in the emitted bandwidth1.

DCS 1800, Digital Communication System

DCS 1800 is a digital cellular standard based on the Global System for Mobile Communications (GSM) international standard. The open architecture of DCS 1800 and GSM allows operators to select equipment from multiple vendors and seamlessly integrate networks. In addition, DCS 1800 operates at a higher frequency range where there is typically more bandwidth available than at the 900 MHz, allowing for higher subscriber density and traffic capacity2.

FDMA, Frequency Division Multiple Access

A technique that assigns specific frequencies and bandwidth from the band of frequencies assigned to particular radio system (Communication satellites, mobile radio, etc) to create individual message channels1.

FHSS, Frequency Hopping Spread Spectrum

Transmission carrier signal structuring in which the frequency is automatically changed according to a given algorithm, selection of the frequency to be transmitted usually is made in a pseudorandom manner from a set of frequencies covering a much wider bandwidth that the information bandwidth, and the intended receiver frequency hops in synchronism with the transmitter in order to retrieve the information in the transmitted

FM, Frequency Modulation

Modulation produced by varying the frequency of the carrier in sympathy with the amplitude for the message signal3.

GSM, Global Standard for Mobile

A time-division based standard for digital wireless transmissions.  It is most prevalently used in Europe1.

LAN, Local-Area Network

LANs are classified according to different criteria including topology, access protocol, transmission medium and the like.  The speed or data transfer rate is another classification as follows:  Low and medium speed LANs:  Data rates up to appx. 15 Mbps which includes the majority of traditional LANs, such as Ethernet, Token Ring and wireless LANs1.

PCS, Personal Communication Service

FCC terminology describing two-way, personal, digital wireless communications systems.  PCS phones use frequencies between 1.85 and 1.99 gigahertz (1850 MHz - 1990 MHz).

TDMA, Time Division Multiple access

For a communications system, the allocation of unique time slots to different users of a common channel.  TDMA may be used in multiple or broadcast transmission, as well.  It is employed extensively in satellite systems, local area networks (LANs), combat net radio systems and physical security installations1.

WAN, Wide Area Network

A network that provides communications services to a larger number of independent users tat are usually served by a local area network (LAN). And is usually spread over a larger geographical area that that of a LAN.  Users may include physical networks, such as Integrated Services Digital Networks (ISDNs), X.25, and T1 networks.  These may serve as a physical or logical, wide-area network environment1.



  1. White, Don.  (1998).  The 1998 EMC Encyclopedia.  Gainsville, Virginia:  EMF-EMI Control, Inc.
  2. Motorola.  (Jack Seller,  Motorola CIG in Arlington Heights, IL).  10/14/96.  Motorola Wins $58 Million Contract to Deploy DCS 1800 PCS System in Hong Kong.  .  Available at:  ©1997 by Motorola, Inc.  Accessed on 12/6/00.
  3. Carne, E. Bryan.  (1995).  Telecommunications Primer:  Signals, Building Blocks, and Networks.  New York, New York.  IEEE Press.  Upper Saddle River, New Jersey.  Prentice Hall, PTR.


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