Telecom related abbreviations ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ********************************************************************** You may not understand why all of these are listed here, but trust me that sooner or later ALL of them are encountered in the telecoms world Send updates to an409307@anon.penet.fi -NeonDreamer '95 ********************************************************************** -=a=- AC Alternating current ADPCM Adaptive differential pulse code modulation AF Audio frequency ALU Arithmetic logic unit AM Amplitude modulation AMI Alternate mark inversion AMPS Advanced mobile phone system ANSI American National Standards Institute AQL Acceptable quality level ASCII American Standard Code for Information Interchange ASPEN Automatic speech exchange network -=b=- BABT British Approvals board for Telecommunications BCD Binary coded decimal BFO Beat frequency oscillator BP Band pass (filter) BRI Basic rate interface BS British Standard BSI British Standards Institution BT British Telecom BVH Buried via hole -=c=- CAI Common air interface CAS Channel associated switching CB Citizen's band CCIR International Radio Consultative Committee CCITT International Telegraph & Telephone Consultative Committee CCS Common-channel signalling CD Collision detection CDMA Code diversion multiple access CEC Commission of European Communities CEN European Commission for Normalisation CENELEC " " " Electrotechnical Normalisation CEPT European Committee of Postal and Telecoms Administration CMI Coded mark inversion CMOS Complementary metal oxide semiconductor CO Central Office Codec Coder/decoder CPE Customer Premises Equipment CPU Central Processing Unit Cr Chromium (chemical symbol) CRC Cyclic redundancy check CRT Cathode Ray Tube CSMA Carrier Sense Multiple Access CT Cordless Telephone CTCSS Continuous tone controlled signalling system CTS Conformance testing services CW Continuous wave -=d=- DASS Digital access signalling system dB Decibel DBE Digital baseband equipment DC Direct current DCE Data circuit equipment DCE Data communications equipment DDI Direct Dialling In DDSN Digital derived services network DECT Digital European cordless telephone d.i.l. Dual-in-line DIV Data in voice DLE Digital local exchange DMSU Digital main switching unit DOV Data over voice DPCM Differential pulse code modulation DPNSS Digital private network signalling system DPSK Differential phase shift keying DSB Double sideband DSC Direct switching centre DTE Data terminating equipment DTI Department of Trade & Industry DTMF Dual-tone multifrequency DUP Data user port -=e=- EBDIC Extended binary-coded decimal interchange code EC European Commission ECTIC " " for Information Technology Certification ECL Emitter coupled logic ECMA European Computer Manufacturers Association EDI Electronic data interface EEC European Economic Community EFTA European Free Trade Association EFWS Electronic four-wire switch EIRP Equivalent isotropic radiated power em Electromagnetic EMC " compatibility EN European standard specification ENV " " " (draft) es Electrostatic ESPA European Selective Paging Manufacturers Assocaition ETS European Telecommunications Standard ETSI " " Standards Institution -=f=- F Farad (unit of capacitance) FAW Frame alignment word FAX Facsimile transmission FCC Federal Communications Commission FCS Frame check sequence FDM Frequency division multiplex FEC Forward error control FEP Front-end processor FET Field-effect transistor FFSK Fast frequency shift keying FIFO First in-first out FIR Finite impulse response FISU Fill-in signal unit FM Frequency modulation FOCC Forward control channel FSK Frequency shift keying FSVFT Frequency shift multichannel voice-frequency telegraphy FVC Forward voice channel -=g=- GHz Hz x 10^9 (gigahertz) GMSK Gaussian minimum shift keying GSC Group switching centre GSM Groupe speciale mobile (French) GTO Gate turn-off (transistor switch) -=h=- H Henry - unit of inductance HDB High-density Bipolar HP High-pass (filter) Hz Hertz (cycles per second) -=i=- IA International alphabet ID Inner diameter IDC Insulation displacement connector IEC International Technical Commission I-ETS Interim European Telecommunications Standard IF Intermediate frequency IFRB International Frequencies Registration Board IIR Infinite impulse response IN Intelligent network ISDN Integrated Services Digital Network ISO International Standards Organisation ISPBX Integrated services private branch exchange IT Information Technology ITSTC " " Steering Committee ITU International Telecommunications Union IVDW Integrated voice data workstation -=j=- JCW Justification control word JDT Justification time slot -=k=- kHz Hz x 10^3 (kilohertz) -=l=- LAN Local area network LAP Local access protocol LCD Liquid crystal display LCS Line control substitution LDR Light dependant resistor LE Local exchange LED Light emitting diode LOGOS Programming language for LCS and EFWS LP Low pass (filter) LRC Longitudinal redundancy check LSB Lower sideband LSI Large scale integration LSSU Link status signal unit -=m=- MDSN Managed data service network MHz Hz x 10^6 (megaherz) MLB Multi layer board MNP Microcom network protocol Modem Modulator/demodulator MOSFET Metal oxide semiconductor FET MPSK Multiphase shift keying MSC Main swirching centre MSI Medium scale integration MSN Multiple subscriber number MSRC Metrology and Standards Requirements Committee MSU Message signal unit MTBF Mean time between faliures MTG Multitone generator MTP Message transfer port MTTR Mean time to repair MUX Multiplexer -=n=- NDC Standard National Number NEL National Engineering Laboratory NET European Telecommunications Standard NEXT Near end cross talk NF Noise figure nF F x 10^-9 (nanofarad) nH H x 10^-9 (nanohenry) Ni Nickel (chemical signal) nm Metres x 10^-9 (nanometre) NPL National Physics Laboratory NRZ Non return to zero NT Network termination NTC Negative temperature coefficient NWML National Weights and Measures Laboratory -=o=- OD Outer diameter Oftel Office of Telecommunications ONA Open network architechture ONP Open network provision OSI Open Systems Interconnection -=p=- PABX Private automatic branch exchange PAD Packet assembler/disassembler PAL Phased alternate line PAL Programmable array logic PAM Pulse amplitude modulation PBX Private branch exchange p.c.b. Printed circuit board PCM Pulse code modulation PCN Personal communications network PCO Public call office pF F x 10^-12 (picofarad) PHILA Phreakers and Hackers in the London Area (group) PIN Personal identification number PIN P intrinsic n junction PLD Programmable logic device PLL Phase locked loop PM Pulse modulation PMR Private mobile radio pn junction of +ve and -ve minority carrier semiconductor materials POCSAG Post Office Code Standardization Advisory Group ppm Parts per million PRI Primary rate interface PROM Programmable ROM ps seconds x 10^-12 (picoseconds) PSE Packet switch exchange PSK Phase shift keying PSN Public switched network PSO Public service operator PSPDN Packet switched public data network PSS Packet switched service PSTN Public switched telephone network PTC Positive temperature coefficient PTH Plated through hole PTO Public telephone network operator PTT Post, telephone, telegraphy -=q=- Q (italic) Quality factor of inductance QAM Quadrature amplitude modulation QPSK Quaternary phase shift keying -=r=- RACE Research and Development in Advanced Communications in Europe RAM Random access memory RECC Reverse control channel RF Radio frequency RIT Receiver incremental tuning RMS Root mean square ROM Read only memory RSGB Radio Society of Great Britain RTTY Radio teletype RVC Reverse voice channel -=s=- SAW Surface acoustic wave Sb Anitmony (chemical symbol) SCOP System contol and operating position SCP System control processor SCR Silicon controlled rectifier SCVF Single channel voice frequency SDH Synchronous digital heirachy SDLC Synchronous data link control SEMKO Swedish standards authority SES Ship earth station s.i.l. Single in line Sn Tin (chemical symbol) SN Subscriber number S/N Signal to noise ratio SONET Synchronous optical network SPC Stored program control SRBP Synthetic resin bonded paper SS7 Signalling system no.7 SSAC Signalling system alternating current SSB Single sideband SSBSC " " supressed carrier SSR Source select register STS Space time space (digital switching) SWG Standard wire guage -=t=- TACS Total access communications system TASI Time assigned speech interpolation TAT Trans Atalantic telephone TC Temperature coefficient TDM Time division multiplex TDMA " " " access TE Terminal equipment TMA Telecommunications Managers Association TNA Telex network adapter TRAC Technical Recommendations Advisory Committee TRS Transmitter repeater station TS Time slot TSS Testing support services TST Time space time (digital switching) TTL Transistor transistor logic TUP Telephone user part TWT Travelling wave tube -=u=- UART Universal asynchronous receiver/transmitter uF F x 10^-6 (microfarad) UHF Ultra high frequency uM Metres x 10^-6 (micrometre) UL Underwriters Listed (USA standard) USB Upper sideband -=v=- Vbe Voltage base emitter VAN Value added network VCO Voltage controlled oscillator VDE German Standards Authority VDR Voltage dependent resistor VDU Visual display unit VHF Very high frequency VRC Vertical redundancy check VSB Vestigial sideband VSWR Voltage standing wave ratio -=w=- WAN Wide area network -=x=- -=y=- -=z=-