Glossary of Terms
0-9
| 0VR | Zero Volt Return |
| 2B+D | Two Bearer Plus Data |
| 2B1Q | 2 Binary 1 Quaternary |
| 2FSK | Binary Frequency Shift Keying |
| 3G | 3rd Generation |
| 4G | 4th Generation |
| 4WTO | 4-Wire Transmission Only |
A
| A/D | Analog-to-Digital converter |
| AAB | Auto Answer Back |
| AAC | Advanced Audio Coding |
| AACS | Advanced Access Content System |
| AAL's | ATM Adaption Layers |
| AAM | Audio Adaptor Modules |
| AAR | Automatic Alternative Route |
| ABI | Application Binary Interface (Unix) |
| ABM | Adaptive Bandwidth Management |
| ABR | Available Bit Rate |
| AC | Alternating Current |
| AC-3 | Audio Codec 3 |
| ACC | Advanced Computer Communications |
| ACD | Automatic Call Distribution |
| ACIA | Asynchronous Communications Interface Adaptor |
| ACK | Acknowledge ( char06 - 06H ) |
| ACM | Audio Compressor Module |
| ACO/LT | Alarm Cut Off / Lamp Test |
| ACP | Adjacent Channel Power |
| ACR | Attenuation to Crosstalk Ratio |
| ACT | Absolute Congestion Threshold |
| ADC | Analogue to Digital Converter |
| ADCCMP | Advanced data Communications Control Procedures (ANSI X3,66) |
| ADI | Automatic or Alternate Digit Inversion |
| ADM | Add/Drop Multiplex |
| ADP | Automatic Data Processing |
| ADPCM | Adaptive Differential Pulse Code Modulation |
| ADSI | Analogue Display Services Interface |
| ADSL | Asymmetric Digital Subscriber Line |
| ADX | Automatic Data Exchange |
| AE | Aerial |
| AES/EBU | Audio Engineering Society/European Broadcasting Union |
| AF | Audio Frequency |
| AFC | Automatic Frequency Control |
| AFD | Active Format Descriptor |
| AFT | Automatic Fine Tuning |
| AGC | Automatic Gain Control |
| AIN | Advanced Intelligent Network |
| AIS | Alarm Indication Signal |
| ALAPB | Autosynchronous Link Access Protocol, Balanced |
| ALC | Automatic Level Control |
| ALI | Automatic Location Identification |
| ALN | Adaptive Logic Network |
| ALSC | Automatic Level and Slope Control |
| ALU | Arithmetic and Logic Unit |
| AM | Amplitude Modulation |
| AMI | Alternate Mark Inversion |
| AML | Amplitude Modulated Link |
| AMLCD | Active Matrix LCD |
| AMPS | American Mobile Phone System/Advanced Mobile Phone System |
| AMUSE | Advanced Multimedia Services for Residential Users |
| AM-VSB | Amplitude Modulation - Vestigial Sideband |
| ANGA | Annual European trade show for Cable, Broadband and Satellite in Cologne Germany |
| ANI | Automatic Number Identification |
| ANM | Advanced Network Management |
| ANS | Automatic Network Synchronization |
| ANS v2 | Automatic Network Synchronization version 2 |
| ANSI | American National Standards Institute |
| ANSU | American National Standards Unit |
| AOS | Alternative Operator Services |
| APC | Angular Physical Contact |
| APD | Avalanche Photo Diode |
| API | Application Programming Interface |
| APPN | Advanced Peer to Peer Networking |
| APS | Automatic Protection Switching |
| AQA | Activity Qualified Access |
| ARCnet | Advancd Resource Computer Network |
| ARM. | Advanced Risc Machines |
| ARPA | Advanced Research Projects Agency |
| ARQ | Automatic Repeat Request |
| ARU | Automatic Response Unit |
| ASC | Abnormal Station Code; Automatic Slope Control |
| ASCII | American Standard Code for Information Interchange |
| ASIC | Application Specific Integrated Circuit |
| ASID | Application Specific Integrated Device |
| ASK | Amplitude Shift Keying |
| ASR | Automatic Send Receive |
| ATDM | Asynchronous Time Division Multiplex(er) |
| ATE | Automated Test Equipment |
| ATIS | Alliance for Telecommunications Industry Solutions |
| ATM | Asynchronous Transfer Mode |
| ATS | Abstract Test Suite |
| ATSC | Advanced Television Systems Committee |
| ATV | Advanced Television |
| AUI | Attachment Unit Interface (Ethernet - 15 oin) |
| AV | Audio-Video |
| AVC | Advanced Video Coding |
| AVI | Audio Video Interleave (Microsoft) |
| AVS | Audio Video Standard |
| AWC | Area Wide Center |
| AWG | American Wire Gauge |
| AWGN | Additive White Gausian Noise |
B
| B8ZS | Binary 8-Zero Suppression |
| BAA | British Astronomical Association |
| BABT | British Approvals Board for Telecommunications |
| Balun | BALanced to Unbalanced |
| BASIC | Beginners All-purpose Symbolic Instruction Code |
| BAT | Bouquet Association Table (multiplex) (part of SI) |
| BAW | Bukk Acoustic Wave |
| BB | Base Band |
| BBTH | Broadband to The Home |
| Bc | Excess Burst Size |
| BCC | Black Check Character |
| BCD | Binary Coded Decimal |
| BCFS | Bidirectional Coding Frame Structure |
| BCH | Base-Chadhuri-Hocquenghem |
| BD | Blu-ray Disc |
| BECN | Backward Explicit Congestion Notification |
| BER | Bit Error Ratio |
| BERT | Bit Error Rate Tester |
| BETRS | Basic Exchange Telecommunications Radio Service |
| B-FRAME | Bidirectionally Predictive-coded (B) Pictures |
| BFSK | Binary Frequency Shift Keying |
| BFT | Binary File Transfer |
| BGA | Bumped (Ball) Grid Array |
| BHCC | Busy Hour Call Completion |
| BIL | Basic impulse Insulation Level |
| BIP-8 | Bit Interleaved Parity-8 |
| BISDN | Broadband Integrated Services Digital Network |
| B-ISDN | Broadband Integrated Services Digital Network |
| BIST | Built In Self Test |
| BISUP | Broadband ISdn User Part |
| BIT. | Built In Test |
| BITS | Building Integrated Timing System |
| BML | Business Management Layer |
| BNC | Bayonet Neil-Councilman Connector |
| BNF | Backus-Naur Form |
| BOP | Bit Oriented Protocol |
| BPF | Band Pass Filter |
| B-pictures | Bidirectionally Predictive Pictures (motion compensation) |
| BPS | b/s, Bits Per Second |
| BPSK | Binary Phase Shift Keying |
| BRA | Basic Rate Access |
| BRAN | Broadband Radio Access Networks |
| BRI | Basic Rate Interface |
| BRISC | Bi-polar/BiCMOS reduced instruction set computer |
| BRR | Bit-Reduction Rate |
| BSC | Binary Synchronous Communications |
| BSF | Band Stop Filter |
| BSI | British Standards Institute |
| BSS | Broadcast Satellite Service |
| BT | British Telecom |
| BTAM | Basic Telecommunications Access Method |
| BTSC | Broadcast Television Systems Committee |
| BW | Bandwidth |
C
| C | Capacitance |
| C/N | Carrier to Noise Ratio |
| CA | Conditional Access; Commercial Announcement |
| CAC | Carrier Access Code |
| CACS | Conditional Access Control System |
| CAD | Computer-Aided Design |
| CAE | Computer-Aided Engineering |
| CAI | Common Air Interface: Confederation of Aerial Industries |
| CAM | Computer Aided Manufacturing |
| CAP | Carrier-less Amplitude and Phase technology |
| CAPs | Competitive Access Providers |
| CARS | Community Antenna Relay Station |
| CAS | Channel Associated Signaling |
| CAT | Conditional Access Table (multiplex) (part of SI) |
| CATG | Computer-Aided Test Generator |
| CATS | Computer Aided Transmitter Simulation |
| CATV | Cable (Community) Aerial Television System |
| CB | Citizens Band |
| Cb, Cr | Chrominance, equivalent to U,(-Y) and V, (R-Y) |
| CBDS | Connectionless Broadband data Service |
| CBR | Constant Bit Rate |
| CBTE | Control Bus Telephony Extension |
| CBW | Central Battery Working |
| CC | Closed Caption |
| CCA | Circuit Card Assembly |
| CCC | Computer Control Center |
| CCD | Charge Coupled Device |
| CCETT | Center Common d'Etudes de Telediffusion et Telecommunications |
| CCF | Custom Calling Features |
| CCFL | Cold Cathode Fluorescent Lamp |
| CCIR-601 | Comite Consultatif International des Radio Communications (France) |
| CCITT | Comite Consultatif International de Telegraphique et Telephone |
| CCM | Companding Conversion Module |
| CCN | Configuration and Control Network |
| CCS | Compression Control System, Computer Control System |
| CCSS | Communications Channel Signalling System |
| CCTV | Closed Circuit Television |
| CCU | Camera Control Unit |
| CD | Carrier Detect; Compact Disc |
| CDDI | Copper Distributed Data Interface |
| CD-I | Compact-Disc Interactive (Phillips) |
| CDM | Code Division Multiplex |
| CDMA | Code Division Multiple Access (Qualcomm) |
| CDPD | Cellular Digital Packet Data |
| CDR | Common Data Rate |
| CDV | Cell Delay Variation |
| CEBus | Consumer Electronics Bus |
| CEC | Consumer Electronics Control |
| CEI | Commission Electronique International |
| CELPC | Code Excited Linear Predictive Coding |
| CEN | Comite Europeen de Nornalisation |
| CENELEC | Comite Europeen de Nornalisation Electrotechnique |
| CEPT | Conference European des Administrations des Postes et Telecommunications |
| CER | Cell Error Rate |
| CEV | Controlled Environmental Vault |
| CFSK | Coherent Frequency Shift Keying |
| CH | Cable Headend |
| CHAP | Challenge handshae Authentication Protocol |
| CHOTS | Corporate Headquarters Office Technology System |
| CI | Craft Interface, Control Information |
| CIC | Carrier Identification Code; Cable In Conduit |
| CIDR | Classless Inter-Domain Routing |
| CIE | Commission International de L'Eclairage |
| CIF | Common Intermediate Format: Common Image Format |
| CIN | Computer Integrated Manufacturing |
| CIR | Committed Information Rate |
| CIRC | Cross-Interleaved Reed-solomon Code. |
| CISC | Complex Instruction Set Computer |
| CISDR | Common Image Structure Data Rate |
| CISPR | Comite International des Perturbations Radiotechniques |
| CIU | Customer Interface Unit |
| CK | Category Key |
| CLASS | Custom Local Area Signaling Services |
| CLI | Cumulative Leakage Index |
| CLID | Calling Line Identification |
| CLNP | ConnectionLess Network Protocol |
| CLNS | ConnectionLess Network Service |
| CLP | Cell Loss Priority |
| CLR | Cell Loss Ratio |
| CLUT | Colour Look Up Table |
| CM | Controller/Multiplexer; Cable Modem |
| CMI | Control Module Idle |
| CMIP | Common Management Information Protocol |
| CMRR | Common-Mode Rejection Ratio |
| CMTS | Cable Modem Termination System |
| CNET | French National Center for Scientific Research |
| CNR | C/N, Carrier to Noise Ratio |
| CO | Central Office |
| COB | Chip On Board |
| COBOL | Common Business Oriented Language |
| CODEC | Code/Decode |
| COFDM | Coded Orthogonal Frequency Division Multiplexing |
| COMSAT | Communications Satellite Corporation |
| COOLAN | Central Office-based Local Area Network |
| CORBA | Common Request Object Broker Architecture |
| COS | Corporation for Open Systems |
| COSHH | Control Of Substances hazardous to Health |
| COST | Cooperation on Science and Technology |
| COT | Customer Originated Trace |
| CPD | Common path Distortion |
| CPE | Customer Premise Equipment; Control Processing Equipment |
| CPFSK | Continuous Phase Frequency Shift Keying |
| CPGA | Ceramic Pin Grid Array |
| CPLD | Complex Programmable Logic Device |
| CPM | Continuous Phase Modulation |
| CPPM | (CPRM) Content Protection for Recordable Media |
| CPS | Characters Per Second |
| CPSS | Control Packet Switching System |
| CPSS v2 | Control Packet Switching System version 2 |
| CPT | Cable Pass Thro |
| CPU | Central Processing Unit |
| CQFP | Ceramic Quad Flatpack |
| CR | Carriage Return ( char 13 - 0DH ) |
| CRC | Cyclic Redundancy Check |
| CRPE | Center for Environmental Physics Research |
| CRT | Cathode Ray Tube |
| CSA | Canadian Standards Association |
| CSDN | Circuit Switched Data Network |
| CSI | Channel Status Information |
| CSMA | Carrier Sense Multiple Access |
| CSMA/CA | Carrier Sense Multiple Access/ Collision Avoidance |
| CSMA/CD | Carrier Sense Multiple Access/ Collision Detection |
| CSO | Composite Second Order |
| CSR | Customer Service Representative |
| CSS | Channel Synchronization Sequence; Content Scamble System |
| CSS (scrambling) | Content Scramble System |
| CSSA | Computing Services and Software Association |
| CSSB/AM | Companded Single Sideband/ Amplitude Modulation |
| CSU | Channel Service Unit |
| CT | Cordless Telephone |
| CTB | Composite Triple Beat |
| CTD | Cell Transfer Delay / Charge Transfer Device |
| CTS | Cable Test System: Clear To Send |
| CVSD | Continuously Variable Slope Delta-modulation |
| CVT | Constant Voltage Transformer |
| CW | Carrier Wave; Continuous Wave; Control Word |
| CWS | Can We Serve |
D
| D/A | Data Acquisition |
| DAB | Digital Audio Broadcasting |
| DAB+ | Digital Audio Broadcasting plus (upgrade to the DAB standard using HE-AAC v2 audio coding) |
| DAC | Digital to Analogue Convertor |
| DALS | Dedicated Line Access |
| DAMA | Demand Assigned Multiple Access |
| DAPSK | Differential Amplitude Phase Shift Keying |
| DASS | Digital Access Signalling Standard |
| DAT | Digital Audio Tape |
| DATV | Direct Antenna Television |
| DAVC | Digital Audio Video Council |
| DAVIC | Digital Audio Video Council |
| dB | Decibel |
| dBc | Decibel relative to Carrier |
| dBc/Hz | Decibel relative to Carrier in one Hz bandwidth (Phase noise) |
| dBi | Decibel relative to isotropic source |
| dBK | Decibel relative to 1 deg K |
| dBm | Decibel Milliwatt |
| dBm0 | Decibel relative to 1mW at point of zero reference level |
| dBm0p | as dBm0 but psophometrically weighted |
| dBm0ps | as dBm0p but weighted for audio transmission |
| dBmV | decibels relative to 1mV |
| DBPSK | Differential Binary Phase-Shift Keying |
| DBPT | Deutsche Bundespost Telecom |
| DBS | Direct Broadcast Satellite |
| dBuV | decibels relative to 1uV |
| dBV | decibels relative to 1V |
| dBW | Decibel Watt |
| DC | Direct Current; Direct Coupler |
| DCC | Direct Card Connect, Digital Compact Cassettes; Data Communications Channel |
| DCD | Data Carrier Detect; Duty Cycle Distortion |
| DCE | Data Communications Equipment: Data Circuit terminating Equipment |
| DCM | Direct Connect Module |
| DCN | Data Communications Network |
| DCP | Data Communications Processor |
| DCS | Diagnostic and Control System, Digital Cross-connect System |
| DCT | Discrete Cosine Transform |
| DD | Dolby Digital |
| DDC | Digital Down Converter |
| DDCMP | Digital Data Communications Message Protocol |
| DDD | Direct long- Distance Dialling |
| DDJ | Data Dependent Jitter |
| DDS | Direct Digital Synthesis, Dataphone Digital Service: Digital Data Service |
| DE | Discard Eligible |
| DEA | Digital Encryption Algorithm |
| DECT | Digital Enhanced Cordless Telecommunications |
| DES | Data Encryption Standard |
| DFB | Distributed Feedback |
| DFM | Design For Manufactureability |
| DFR | Digital Fault Recorder |
| DFSK | Differential Phase Shift Keying |
| DFT | Design For Test: Discrete Fourier Transform |
| DHCP | Dynamic Host Configuration Protocol |
| DIA | Data Interface Adapter |
| DID | Direct Inward Dialing |
| DIN | Deutsche Industrie Normen |
| DisEqC | Digital Satellite Equipment Control |
| DIU | Data Interface Unit |
| DLC | Digital Loop Carrier: Data Link Control |
| DLIC | Data Link Connection Identifier |
| DLSw | Data Link Switching |
| DM | Delta Modulation |
| DMA | Direct Memory Access |
| DMB | Digital Multimedia Broadcasting |
| DMM | Digital MultiMeter |
| DMS | Digital Multiplex Systems |
| DMT | Design Maturity Testing; Discrete Multitone |
| DNIC | Digital Network Interface Circuit |
| DNS | Domain Name System ( Internet ) |
| DOC | Department of Communications |
| DOCSIS | Data Over Cable Service Interface Specification |
| DOPSK | Differential Offset Phase Shift Keying |
| DOS | Disc Operating System |
| DP | Dial Pulsing |
| DPAK | Power Transistor Surface Mount Package |
| DPCM | Differential Pulse Code Modulation |
| DPDT | Double-Pole, Double-Throw ( switch ) |
| DPM | Digital Processor Module |
| DPM2 | Digital Processor Module 2 |
| DPN | Data Packet Network |
| DPO | Dial Pulse Originate |
| DPSK | Differential Phase Shift Keying |
| DPT | Dial Pulse Terminate |
| DQPSK | Differential Quadrature Phase Shift Keying |
| DR. | Dynamic Range |
| DRAGA | Dual Rate Adaption Gate Array |
| DRAM | Dynamic Random Access Memory |
| DRC | Dynamic Range Control |
| DRM | Digital Radio Mondiale |
| DS | Digital Signal |
| DS/CDMA | Direct Sequence CDMA |
| DS/PPM | Direct Sequence Pulse Position Modulation |
| DS0 | Digital Service level 0 |
| DS-0 | Digital Signal Level 0 (64Kbps), Usually single voice channel |
| DS-1 | Digital Signal Level 1 (1.554 Mbps) 24 voice or other data services |
| DS-3 | Digital Signal Level 3 (45 Mbps) 28 DS-1 circuits |
| DSB | Double Sideband Modulation |
| DSBSC | Double Sideband Suppressed Carrier |
| DSD | Direct Stream Digital |
| DSI | Digital Speech Interpolation |
| DSL | Digital Subscriber Line |
| DSM | Digital Storage Medium |
| DSNG | Digital Satellite News Gathering |
| DSP | Digital Signal Processing |
| DSR | Digital Storage and Retrieval: Data Set Ready |
| DSS | Digital Satellite Service or Digital Satellite System |
| DSSS | Direct Sequence Spread Spectrum |
| DS-SSMA | Direct Sequence-Spread Spectrum Multiple Access |
| DSU | Digital Switch Unit, Data Service Unit |
| DSX-1 | Digital Signal Cross-Connect Level 1 |
| DTC | Department of Trade Controls; Decoder Time Clock |
| DTE | Data Termination Equipment |
| DTH | Direct To Home |
| DTI | Department of Trade and Industry |
| DTM | Digital TransModulation |
| DTMF | Dual Tone Multiple Frequency |
| DTR | Data Terminal Ready |
| DTS | Digital Time Stamp |
| DTS (sound system) | Digital Theater Systems |
| DTT | Digital Terrestrial Television |
| dTTb | Digital Terrestrial Television Broadcasting |
| DTU | Data Termination Unit |
| DTVC | Digital Television by Cable |
| DUT | Device Under Test |
| DV | Digital Video |
| DVB | Digital Video Broadcasting |
| DVB-C | Digital Video Broadcasting - Cable |
| DVB-C2 | Digital Video Broadcasting - Cable - Second Generation |
| DVB-H | Digital Video Broadcasting - Handheld |
| DVB-NGH | Digital Video Broadcasting - Next Generation Handheld |
| DVB-S | Digital Video Broadcasting - Satellite |
| DVB-S2 | Digital Video Broadcasting - Satellite - Second Generation |
| DVB-SH | Digital Video Broadcasting - Satellite Handheld |
| DVB-T | Digital Video Broadcasting - Terrestrial |
| DVB-T2 | Digital Video Broadcasting - Terrestrial - Second Generation |
| DVC | Digital Video Compression |
| DVD | Digital Video Disc |
| DVI | Digital Visual Interface |
| DVMD | Digital Video Measurement Decoder |
| DVQ | Digital Video Quality |
| DVRM | Digital Video Realtime Monitor |
| DVT | Design Verification Test |
| DWDM | Dense Wavelength Division Multiplexing |
| DWMT | Discrete Wavelet Multitone |
| DWS | Dialable Wideband Service |
| DX | Digital Cross-connect |
E-F
| E1 | European Signal Level 1 (Line Rate: 2.048 Mbps) |
| E2 | European Signal Level 2 (Line Rate: 8.448 Mbps) |
| E3 | European Signal Level 3 (Line Rate: 34.368 Mbps) |
| EAEO | Equal Access End Office |
| EAS | Emergency Alert System |
| EAX | Electronic Automatic Exchange; Extended Area Service |
| EBCDC | Extended Binary Coded Decimal Code |
| EBCDIC | Extended Binary Coded Decimal Interchange Code |
| EBU | European Broadcasting Union |
| EC | European Community, Earth Calling |
| ECL | Emitter Coupled Logic |
| ECM | Entitlement Control Messages / Electronic Counter-Measures |
| ECS | European Communications Satellite |
| ECSA | Exchange carrier Standards Association |
| EDC | Error Detection and Correction |
| EDFA | Erbium-Doped Fibre Amplifier (1550nm) |
| EDGE | Enhanced Data Rates for Global Evolution |
| EDI | Electronic Data Exchange, Electronic Document Interchange |
| EDS | Electronic Data Service |
| EDTV | Extended Definition Television |
| EEPROM | Electrically Erasable Programmable Read-only Memory |
| EFP | Electronic Film Production |
| EGP | Exterior Gateway Protocol |
| EIA | Electronic Industries Association |
| EIAJ | Electronic Industry Association Japan |
| EIRP | Effective Isotropic Radiated Power; Equivalent Isotropic Radiated Power |
| EISA | Enhanced Industry Standard Architecture |
| EIT | Event Information Table (multiplex) (part of SI) |
| ELF | Extremely Low Frequency |
| ELGDVB | European Launch Group for Digital Video Broadcasting |
| EM | ElectroMagnetic |
| EMC | Electromagnetic Capability |
| EMF | Electromagnetic Flux |
| EMI | Electromagnetic Interference |
| EML | Element Management Area |
| EMM | Entitlement Management Messages |
| EMP | Electromagnetic Pulse |
| EMR | European Metal Recycling |
| ENF | Equivalent Noise Floor |
| ENG | Electronic News Gathering |
| ENQ | Enquiry |
| EO&C | Expert Observation & Commentary |
| EOF | End Of File / End Of Frame |
| EOP | End Of Packet |
| EOT | End Of Transmission |
| EPAC | Electricaly Programmable Analogue Circuit |
| EPG | Electronic Program Guide |
| EPLD | Erasable Programmable Device |
| EPROM | Erasable Programmable Read-only Memory |
| EQ | Equipment Qualification |
| ERA | Electrically Reconfigurable Array |
| ERL | Echo Return Loss |
| ERM | Electromagnetic compatibility and Radio spectrum Matters |
| ERP | Effective Radiated Power |
| ESA | Emergency Stand Alone |
| ESCR | Elementary Stream Clock Reference |
| ESD | Electrostatic Discharge |
| ESDi | Enhanced Small Device Interface |
| ESF | Extended Super Frame |
| ESP | Enhanced Service Provider |
| ESS | Electronic Switching System |
| ET | Emerging Technologies |
| ETB | End of Text Block |
| ETDMA | Enhanced Time Division Multiple Access |
| ETS | European Technical Standard |
| ETSI | European Telecommunication Standard Institute |
| EVC | Enhanced Video Connector ( VESA ) |
| EVM | Error Vector Magnitude |
| EWP | Electronic White Pages |
| FAD | Frame Relay Assembler / Disassembler |
| FAP | Flexible Access Protocol |
| FAS | Frame Alignment Signal |
| FAT | Factory Acceptance Test / File Allocation Table |
| FAX | Facsimile |
| FC | Fibre Channel |
| FCC | Federal Communications Commission |
| FCP | Fault Condition Propagation |
| FCS | Frame Check Sequence |
| FDDI | Fibre Distributed Data Interface |
| FDL | Facility Data Link |
| FDM | Frequency Division Multiplexing |
| FDMA | Frequency Division Multiple Access |
| FDX | Full DupleX |
| FEC | Forward Error Correction |
| FECN | Forward Explicit Congestion Notification |
| FED | Field Emission Display |
| FEI | Federation of the Electronics Industry |
| FERF | Far End Receive Failure |
| FFT | Fast Fourier Transformation |
| FHT | Fast Hartley Transform |
| FIC | Fast Information Channel |
| FIFO | First In First Out |
| FIP | FASTbus Interconnect Panel |
| FIR | Finite Impulse Response (Digital Filtering Technique) |
| FIT | Failures in 1 Billion Hours |
| FITL | Fibre In The Loop |
| FLAG | Fibre Link Around the Globe. |
| FLIR | Forward Looking Infra-Red |
| FLP | Fluorescent Panel |
| FM | Frequency Modulation |
| FML | Frequency Modulation Link |
| FMO | Frequency Modulation Oscillator |
| FO | Fibre Optic |
| FOSE | Fibre Optic Splice Enclosure |
| FOT | Fibre Optic Transceiver |
| FOTS | Fibre Optic Transmission Systems |
| F-P | Fabry-Perot |
| FPD | Flat Panel Display |
| FPGA | Field Programmable Gate Arrays |
| FPLD | Field Programmable Logic Device |
| fps | frames per second |
| FR | Frame Relay |
| FRAD | Frame Relay Assembly/ Disassembler |
| FRE | Frame Relay Engine |
| FRS | Frame Relay Switch |
| FSIC | Function Specific Integrated Circuit |
| FSK | Frequency Shift Keying |
| FSM | Field Strength Meter |
| FSN | Full Service Network |
| FSS | Fixed Satellite Services |
| FT1 | Fractional T1 |
| FTAM | File Transfer and Access Management |
| FTP | File Transfer Protocol |
| FTTC | Fibre To The Curb |
| FTTF | Fibre To The Feeder |
| FTTH | Fibre To The Home |
| FttX | Fibre to the Whatever. |
| FWHM | Full Width Half Maxima |
| FX | Foreign Exchange Service - Office |
| FXO | Foreign Exchange |
| FXS | Foreign Exchange Service - Subscriber |
G-H-I
|
G/T |
Gain-to-Noise Temperature Ratio |
| G3 | Gadolinium Gallium Garnet |
| G703 | 34.4 Mb/s |
| G709 | 155.2 Mb/s |
| G751 | 139.264 Mb/s |
| Ga As P | Gallium Arsenide Phosphide |
| Ga N | Gallium Nitride |
| GaAsFET | Gallium Arsenide Field Effect Transistor |
| GARP | Global Atmospheric Research Program |
| GDI | Generic Data Interface |
| GENEVA | GenRad Extended VXIbus Archtecture |
| GEO | Geosynchronous Earth Orbit |
| GFC | General Facilities Card |
| GFMSK | Gausian Filtering Minimum Shift Keying |
| GFSK | Gausian filtered Frequency Shift Keying |
| GHz | Gigahertz |
| GI | Graded Index |
| GIS | Geographical Information System |
| GLONASS | GLObal NAvigation Satellite System |
| GMS | Geostationary Meteorological Satellite |
| GMSK | Gausian Minimum Shift Keying |
| GND | Ground |
| GOES | Geostationary Operational Environmental Satellite |
| GOMS | Geostationary Operational Meteorological Satellite |
| GOP | Group Of Pictures (motion compensation) |
| GPIB | General Purpose Interface Bus (IEEE-488,HP-1B; Transfer rate <1 Mbps) |
| GPRS | General Packet Radio Service |
| GPS | Global Positioning System |
| GS | Ground Start |
| GSM | Global Standard for Mobile communication |
| GUI | Graphical User Interface |
| H.261 | ITU-T video coding standard primarily for ISDN |
| H.264 | Coding standard for video compression |
| H.264/MPEG-4 AVC | Coding standard for video compression developed by ITU-T |
| HA | Home Access |
| HAD. | Hole Accumulation Diode |
| HAN | Home Area Network |
| HB | Home Bridge |
| HBI | Horizontal Blanking Interval |
| HC | Home Client |
| HCI | Host Controller Interface |
| HCM | High Capacity Multiplexing |
| HCT | Home Communication Terminal |
| HCV | High Capacity Voice |
| HD | High Definition |
| HDB | High Density Bi-polar |
| HDCP | High-bandwidth Digital Content Protection |
| HDD | Hard Disk Drive |
| HDLC | High Level Data Link Controller |
| HDMI | High-Definition Multimedia Interface |
| HDSL | High bit rate Digital Subscriber Line |
| HDT | Host Digital Terminal; Headend Digital Terminal |
| HDTV | High Definition Television |
| HDX | Half Duplex Transmission |
| HE-AAC | High Efficiency Advanced Audio Coding standardised in ISO/IEC 14496-3 |
| HEMT | High Electron Mobility Transistor |
| HEX | Hexadecimal Notation |
| HF | Hih Frequency |
| HFC | Hybrid Fibre-Coax |
| HFW | Hybrid Fibre Wireless |
| HID | Human Interface Device |
| Hiperlan | High Performance Radio LAN |
| HITS | Headend In The Sky |
| HLD | High Level Design |
| HLDD | High Level Design Document |
| HLR | Home Location Register |
| HMU | Home Monitoring Unit |
| HPB | Half-Power Bandwidth |
| HPF | High Pass Filter |
| HRC | Harmonically Related Carriers |
| HSCD | High Speed Data Cable |
| HSCSD | High Speed Circuit Switching Data |
| HSSI | High Speed Serial Interface |
| HTML | HyperText Markup Language |
| HTTP | HyperText Transfer Protocol |
| HUD | Head-Up Display |
| Hz | Hertz ( = Cycles per Second ) |
| I | In-Phase |
| I, Q | In Phase, Quadrature phase components of the modulated signal. |
| I/O | Input Output |
| IBC | International Broadcasting Conference) |
| IBOC | In Band On Channel |
| IBPSK | Independent Binary Phase Shift Keying |
| IBR | Intermediate Bit Rate |
| IC | Integrated Circuit |
| ICC | Incremental Coherent Carriers |
| ICI | Inter-carrier Interface |
| ICN | Integrated Community Network |
| ICS | Integrated Communication System |
| ICW | Interrupted Continuous Wave |
| IDCT | Inverse Discrete Cosine Transform |
| IDD | International Direct Dialling |
| IDF | Intermediate Distribution Frame |
| IDLC | Integrated Digital Loop Carrier |
| IDN | Integrated Digital Network |
| IDP | Internet data Packet |
| IEC | International Electrotechnical Commission |
| IEEE | Institute of Electrical and Electronic Engineers |
| IF | Intermediate Frequency |
| IFFT | Inverse Fast Fourier Transformation |
| I-FRAME | Intra Picture Frame Structure |
| IFRB | International Frequency Registration Board |
| IGP | Interior Gateway Protocol |
| IHC | In Home Cabling |
| IIR | Infinite Impulse Response. (Digital Filtering Technique) |
| IM | Inter-Modulation |
| IMAP | Internet Message Access Protocol |
| IMD | Inter-Modulation Distortion |
| IMUX | Input Multiplexer |
| INMS | Integrated Network Management System |
| IOR | Index Of Refraction |
| IP | Internet Protocol; Intelligent Peripherals; Information Provider; Interlectual Property |
| I-pictures | Intra-pictures (motion compensated) |
| IPPV | Impulse Pay Per View |
| IPR | Intellectual Property Rights |
| Ipv4 | Internet Protocol version 4 |
| Ipv6 | Internet Protocol version 6 |
| IRB | Input Redundancy Bus |
| IRC | Incrementally Related Carriers |
| IRD | Integrated Receiver Decoder |
| IRED | Infra Red Emitting Diode |
| IRIG-B | Intermediate Range Instrumentation Group (Time Code Format) |
| IRL | Inter-Repeater Link |
| IRP | Integrated Receiver Processor |
| IRQ | Interrupt Request |
| IRT | Integrated Receiver Transcoder |
| IS2DN | Integrated Special Services Digital Network |
| ISA | Industry Standard Architecture |
| ISB | Independent Side Band |
| ISD | International Subscriber Dialling |
| ISDN | Integrated Services Digital Network; Integrated Switched Digital Network |
| ISI | International Symbol Interface; InterSymbol Interference |
| ISO | International Standards Organization |
| ISP | In System Programmability /Internet Service Providere |
| ISSU | Intelligent System Synchronization Unit |
| ISU | Integrated Services Unit |
| ITA | Interface Test Adapter |
| ITB | Integral Token Ring Bridge |
| ITFS | Instructional Television Fixed Service |
| ITU | International Telecommunications Union |
| ITV | Interactive Television |
| IVR | Interactive Voice Response |
| IWU | Interworking Unit |
J-K-L-M
| JB7 | Jam Bit 7 |
| JEDEC | Joint Electronic Devices Engineering Council |
| JESSI | Joint European Sub-micron Silicon Initiative |
| JISC | Japanese Industrial Standards Committee |
| JIT | Just In Time |
| JND | Just Noticeable Difference |
| JPEG | Joint Photographic Experts Group |
| JTAG | Joint Test Action Group (IEE 1149.1 Serial bus standard) |
| KB | KiloBytes |
| kbps | Kilo Bits Per Second |
| KHz | Kilohertz |
| Ksps | Kilosymbols Per Second |
| KSU | Key Service Unit |
| LAN | Local Area Network |
| LAPB | Link Access Protocol - Balanced |
| LAP-M | Link Access Protocol - Modem |
| LASER | Light Amplification by Stimulated Emission of Radiation |
| LAT | Local Aea Transport ( DEC, Ethernet ) |
| LBO | Line Build Out |
| LCD | Liquid Crystal Display |
| LCDC | Loop Calling Disconnect Clear |
| LCS | Leased Circuit Service |
| LDF | Low Density Foam ( cables ) |
| LDS | Local Distribution Service |
| LEC | Local Exchange Carriers |
| LED | Light Emitting Diode |
| LEO | Low Earth Orbit |
| LF | Low Frequency |
| LGE | Loop start Ground start - Exchange |
| LGS | Loop start Ground start - Subscriber |
| LHCP | Left Hand Circular polarisation |
| LIDAR | Lightning Detection and Ranging. |
| LIFO | Last In First Out |
| LIM | Line Interface Module |
| LLD | Low Level Design |
| LLDD | Low Level Design Document |
| LMDS | Local Multipoint Distribution Service |
| LMI | Local Management Interface |
| LNA | Low Noise Amplifier |
| LNB | Low Noise Block converter |
| LNC | Low Noise Converter |
| LO | Local Oscillator |
| LON | Local Operating Network |
| LOP | Local Origination Programming |
| LOS | Line Of Sight: Loss Of Signal |
| LPC | Linear Predictive Coding |
| LPCM | Linear Pulse Code Modulation |
| LPF | Lowpass Filter |
| LPM | Lines Per Minute |
| LPRA | Low Power Radio Authority |
| LPS | Lightning Protection System |
| LPTV | Low Power Television |
| LR | Line Reversal |
| LRB | Loop Reverse Battery |
| LRC | Longitudinal Redundancy Check |
| LS | Loop Start |
| LSB | Least Significant Bit |
| LSI | Large Scale Integration |
| LSOH | Low Smoke Zero Halogen |
| LTE | Long Term Evolution - pre-4G standardby the 3rd Generation Partnership Project (3GPP) for increase of data capacity and speed of mobile (broadband) networks |
| LTE Advanced | Long Term Evolution Advanced - Preliminary mobile communication standard, and candidate 4G system by the 3rd Generation Partnership Project (3GPP) as a major enhancement of the LTE standard. |
| LUF | Lowest Usable Frequency |
| Luma | Luminance (Y) |
| LUT | Look Up Table |
| LVA | Long Vertical Aperture |
| LVD | Low Voltage Directive |
| M3VDS | Millimeter-wave Multi-channel Multipoint Video Distribution System |
| MAC | Multiple Analog Component format: Multiplying Accumulator |
| MAM | Modulator Adaptor Module |
| MAN | Metropolitan Area Network |
| MAP | Manufacturing Automation Protocol / Multiple Access Protocols |
| MARECS | MARitime European Communications Satellite |
| MASCAM | Mask-pattern Adaptive Sub-band coding and Multiplexing |
| MATV | Master Antenna Television |
| max | Maximum |
| MBG | Multilocation Business Group |
| Mbone | Multicast backBone ( Internet ) |
| Mbps | Megabits Per Second |
| MCM | Multi Chip Module |
| MCPC | Multiple Channels Per Carrier |
| MCR | Master Control Room |
| MCT | Mild Congestion Threshold |
| MCTDMA | Multiple Carrier Time Division Multiple Access |
| MCW | Modulated Continuous Wave |
| MDDB | Multidrop Data Bridge |
| MDF | Main Distribution Frame |
| MDS | Multipoint Distribution Service: Microwave Distribution System |
| MDU | Multiple Dwelling Unit |
| MEC | Multiplexer Encryptor Encoder |
| MELF | Metal Electrode Face Bonded |
| MEMS | Micro-ElectroMechanical Systems |
| MER | Modulation Error Ratio |
| MF | Medium Frequency; Multi Frequency |
| MFLOPS | Million Floating-Point Operations Per Second |
| MFN | Multi Frequency Network / Modified Frequency Modulation |
| MFSK | Multiple/ Minimum Frequency Shift Keying |
| MGC | Manual Gain Control |
| MHEG-5 | Multimedia & Hypermedia Information Coding Expert Group |
| MHS | Message Handling System/ Service |
| MHz | Megahertz |
| MIBS | Management Information Bases |
| MIC | Microwave Integrated Circuit |
| MID | Mobile Information Device |
| MIER | Modulation Error Ratio |
| MIME | Multipurpose Internet Mail Extensions |
| MIMO | Multiple-Input and Multiple-Output |
| MIP | Megaframe Initialization Packet |
| MIPS | Million Instructions Per Second |
| MISO | Multiple-Input and Single-Output |
| MJU | Multijunction Unit |
| MLP | Meridian Lossless Compression ;Micro Lead Package |
| MM | Multimode |
| MMDS | Multichannel Multipoint Distribution Service (Microwave) |
| MMIC | Monolithic Microwave Integrated Circuit |
| MMU | Memory Management Unit |
| MNP | Microcom Networking Protocol |
| MOAM | Modulator Output Adaptor Module |
| Mod | Modulator |
| MODEM | Modulator/ Demodulator |
| MOS | Metal-Oxide Semiconductor; Mean Opinion Score |
| MOVPE | Metallic Organic Vapor Phase Epitaxy |
| MP3 | MPEG-1 or MPEG-2 Audio Layer 3 (or III) - lossy compression algorithm for audio |
| MP4 | MPEG-4 Part 14 - ISO/IEC 14496-14:2003, multimedia container format standard |
| MPAC | Mask Programmable Analogue Circuit |
| MPEG-1 | Motion Picture Experts Group (Digital Compression Standard ISO 11172) |
| MPEG-1 Audio Layer 3 | Extension to the MPEG-1 standard for audio (ISO/IEC 11172-3, MPEG-1 Part 3) |
| MPEG-2 | Motion Picture Experts Group (Digital Compression Standard ISO 13818) |
| MPEG-4 | Motion Picture Experts Group (Digital Compression Standard ISO/IEC 14496 - Coding of audio-visual objects) |
| MPLS | Multiprotocol Label Switching |
| MQFP | Metric Quad Flat Pack |
| MQORC | Modified Quadrature Overlapped Raised Cosine' |
| MRD | Manual Ring Down |
| MSA | Metropolitan Service Area |
| MSB | Most Significant Bit |
| MSC | Main Service Channel |
| MSK | Minimum Shift Keying |
| MSO | Multiple System Operator |
| Msps | Megasymbols Per Second |
| MSRN | Multiple Station Roaming Number |
| MSS | Mobile Satellite Services |
| MTBF | Mean Time Between Failure |
| MTF | Modulation Transfer Function |
| MTS | Modem Termination System; Multichannel Television Sound |
| MTSO | Mobile Telephone Switching Office |
| MTTR | Mean Time To Repairs |
| MUF | Maximum Usable Frequency |
| MULDEX | Multiplexer/ Demultiplexer |
| MUSA | Multiple Unit Steerable Array |
| MUSE | Multiple Sub-Nyquist Encoding |
| MUSHRA | MUltiple Stimuli with Hidden Reference and Anchor |
| MUSICAM | Masking Pattern Universal Sub-band Integrated Coding and Multiplexing |
| MUX | Multiplexer |
| MVIP | Multi Vendor Integration Protocol |
| MXIbus | Multisystem Extension Interface Bus (Transfer Rate <20 Mbytes per second) |
N-O-P
| NA | Numerical Aperture |
| NAB | National Association of Broadcasters |
| NADG | North American Digital Group |
| NAK | Negative Acknowledgement |
| NAMAS | NAtional Measurement Accreditation Service |
| NAP | Network Access Points |
| NAT4882 | Industries First IEEE-488.2 Controller Chip |
| NAU | Network Addressable Unit |
| NBFM | Narrow Band Frequency Modulation |
| NBS | National Bureau of Standards |
| NC | Network Congestion / No Connection |
| NCC | National Control Centers Telecommunication System |
| NCI | Network Control Interface |
| NCP | Network Control Program |
| NCTA | North American Cable Television Association |
| ND:YAG | Neodymium Yttrium Aluminum Garnet |
| NE | Network Element |
| NEC | Network Electrical Code |
| NEMA | National Electrical Manufactures Association |
| NEP | Noise Equivalent Power |
| NEXT | Near-End Crosstalk |
| NF | Noise Figure |
| NFAS | Non-Frame Alignment Signal |
| NFS | Network Filing System |
| NIC | Network Information Carrier |
| NICAM | Near Instantaneous Companded Audio Multiplex |
| NICQA | National Inspection Council Quality Assurance |
| NID | Network Interface Device |
| NII | National Information Infrastructure |
| NIIR | Russian Scientific Research Institute of Radio Communications |
| NIT | Network Information Table (multiplex) (part of SI) |
| NIU | Network Interface Unit |
| nm | nanometres |
| NML | Network Management Layer |
| NMS | Network Management System |
| NMTI | Node Management Terminal Interface |
| NNI | Network-Network Interface; Network-Node Interface |
| NOAA | National Oceanographic and Atmospheric Administration |
| NOC | Network Operations Center |
| NRE | Non-Recurring Engineering |
| NRZ | Non Return to Zero |
| NRZI | Non Return to Zero Inverted |
| NSF | Non-Standard Facilities |
| NT | Network Termination |
| NTSC | National Television Standards Committee |
| NTU | Network Termination Unit |
| NUI | Network User Identification |
| NVM | Non-Volatile Memory |
| NVOD | Near Video On Demand |
| NVP | Nominal Velocity of Propagation. |
| OA | Office Automation |
| OAA | Over Air Addressing |
| OC | Optical Carrier |
| OC-12 | 655 Mb/s |
| OC-3 | 150 Mb/s |
| OC-48 | 2.4 Gb/s |
| OCC | Other Common Carrier |
| OC-N | Optical Carrier - N |
| OCU | Office Channel Unit |
| OCU-DP | Office Channel Unit - Data Port |
| ODI | Open Data-link Interface |
| OEM | Original Equipment Manufacture |
| OFDM | Orthogonal Frequency Division Multiplexing |
| OFDMA | Orthogonal Frequency Division Multiple Access |
| OFS | Operational Fixed Station |
| OIRT | Organisation International de Radiodiffusion et Television |
| OMT | Orthognal Mode Transducer |
| OMUX | Output Multiplexer |
| ONA | Open Network Architecture |
| ONU | Optical Network Units |
| OOF | Out Of Frame |
| OOK | On Off Keying |
| OOP | Object Oriented Programming |
| OOS | Out Of Service |
| OPGW | overhead Optical Ground Wave |
| OPX | Off Premises Extension |
| OQPSK | Offset Quadrature Phase Shift Keying |
| ORL | Optical Return Loss |
| OSC | Oscillator |
| OSD | On Screen Display |
| OSI | Open Systems Interconnect |
| OSPF | Open Shortest Path First |
| OSS | Operations Support System |
| OTDR | Optical Time Domain Reflectometer |
| OTG | On Time Guarantee |
| OTN | Optical Transmission Nodes |
| OTP | One Time Programmable |
| OTS | Orbital Test Satellite |
| OWF | Optimum Working Frequency |
| P | French term for SCART (connector) |
| P | Puncturing |
| PABX | Private Automatic Branch Exchange |
| PAD | Packet Assembler/Disassembler, Program Associated Data |
| PAL | Phase Alternating Line; Programmable Array Logic |
| PALC | Plasma Addressed LCD |
| PALE | Programmable Atomic Logic Elements |
| PAM | Pulse-Amplitude Modulation |
| PARS | Private Advanced Radio Service |
| PAT | Program Association Table, (multiplex)(part of SI); Power Alignment Technology |
| PAX | Private Automatic Exchange |
| PBGA | Plastic Ball Grid Array |
| PBX | Private Branch Exchange |
| PC | Personal Computer; Printed Circuit |
| PCB | Printed Circuit Board |
| PCC | Programmer Control Center |
| PCI | Peripheral Component Interconnect |
| PCM | Pulse Code Modulation |
| PCMCIA | Personal Computer Memory Card International Association |
| PCN | Personal Communications Network |
| PCR | Programmable Clock Reference |
| PCS | Program Control System; Personal Communication Services |
| PCSN | Private Circuit Switching Network |
| Pulse Density Function; Portable Document Format | |
| PDFA | Praesodymium-Doped Fibre Amplifiers (1310nm) |
| PDH | Plesiosyncronous Digital Heirarchy |
| PDM | Phase Division Multiplex ;Passive Display Model: Pulse Duration Modulation |
| PDMI | Portable Digital Media Interface |
| PDN | Public Data Network; Primary Directory Number |
| PECL | Pseudo ___________ |
| PEL | Picture Element |
| PES | Packetized Elementary Stream, Personal Earth Station |
| PFD | Power Flux Density |
| PFM | Pulse Frequency Modulation |
| P-Frame | Predictive-coded (P) Pictures Frame Structure |
| PGA | Pin Grid Array |
| PID | Program Identification, Packet Identifier |
| PIN | Personal Identification Number |
| PIO | Programmable Input Output |
| PIV | Peak Inverse |
| PIXEL | Peak Inverse Voltage |
| PK | Program Key |
| PKI0 | Public Key Infrastructure |
| PLA | Programmable Logic Array |
| PLAR | Private Line Automatic Ring down |
| PLC | Programmable Logic Controller |
| PLCC | Plastic Leaded Chip Carrier |
| PLD | Programmable Logic Device |
| PLL | Phase Locked Loop |
| PLMN | Public Land Mobile Network |
| PLR | Private Link Repeater |
| PLUGE | Picture Line Up Generator Equipment |
| PM | Phase Modulation, Poly-phase Matched |
| PMR | Private Mobile Radio |
| PMT | Program Map Table (multiplex) (part of SI) |
| PN | Pseudo-random Number |
| PNNI | Private Network to Network Interface |
| POCSAG | Post Office Code Standardisation Advisory Group |
| POF | Plastic Optical Fibre |
| PON | Passive Optical Network |
| POP | Proof Of Performance / Point of Presence |
| POS | Programmable Option Select |
| POTS | Plain Old Telephone Service |
| P-pictures | Predictive pictures |
| PPM | Pulse Position Modulation |
| PPP | Point - to - Point Protocol |
| PPV | Pay Per View |
| PQFP | Plastic Quad Flatpack |
| PRA | Primary Rate Access ( 2Mb/s - ISDN ) |
| PRBS | Pseudo Random Binary Sequence; Pseudo Random Bit Sequence |
| PRF | Pulse Repetition Frequency |
| PRI | Primary Rate Interface |
| PROM | Programmable Read Only Memory |
| PSD | Power Spectral Density; Programmable System Device |
| PSDN | Packet Switched Data Network |
| PSI | Program Specific Information (part of SI) |
| PSK | Phase Shift Keying |
| PSS | Packet Switched System/ Service |
| PSTN | Public Switched Telephone Network |
| PSTS | Profile Specific Test Specification |
| PSU | Power Supply Unit |
| PT | Packet Terminal |
| PTL | PASS Transistor Logic |
| PTM | Pulse Time Modulation |
| PTS | Presentation Time Stamp |
| PTT | Postal, Telephone and Telegraph |
| PTX | Packet Transfer Exchange |
| PVC | Permanent Virtual Connection |
| PVR | Personal Video Recorder |
| PWA | Printed Wiring Assembly |
| PWB | Printed Wiring Board |
| PWM | Pulse-Width Modulation |
| PWR | Power |
Q-R-S
| Q | Quadrature |
| Q&R | Quality and Reliability |
| QA | Quality Assurance: Assessment |
| QAM | Quadrature Amplitude Modulation |
| QASK | Quadrature Amplitude Shift Keying |
| QCIF | Quarter Common Intermediate/ Image Format |
| QDPSK | Quadrature Differential Phase Shift Keying |
| QDU | Quantisation Distortion Units |
| QEF | Quasi Error Free (BER <10-11) (SNR 24.5dB FOR 64QAM) |
| QFP | Quad Flat Package |
| QFSK | Quadrature Frequency Shift Keying |
| QIRP | QAM Integrated Receiver Processor |
| QORS | Quadrature Offset Raised Cosine |
| QOS | Quality Of Service |
| QOSRC | Quadrature Overlapped Squared Raised Cosine |
| QPR | Quadrature Partial Response |
| QPRS | Quadrature Partial Response Signaling |
| QPSE | Queued Packet Synchronous Exchange |
| QPSK | Quadrature Phase Shift Keying, Quaternary Phase Shift Keying |
| QSOP | Quater Small Outline Package |
| QWIP | Quantum Well Infrared Photo Detector |
| R | Randomised Sequence |
| R&D | Research and Development |
| R2D | R2 Digital Signaling |
| RAD | Remote Antenna Device |
| RADAR | Radio Detection And Ranging |
| RAE | Royal Academy of Engineering |
| RAID | Redundant Array of Inexpensive Discs |
| RAM | Random Access Memory |
| RAPID | Reserved Alternate Path with Immediate Diversion |
| RBER | Residual Bit Error Rate |
| RBS | Robbed Bit Signaling, Reserved Battery Signaling |
| RCC | Radio Common Carrier |
| RCI | Relay Control Interface |
| RDT | Remote Digital Terminal |
| RE. | Remote Extension |
| REM EXT | Remote Extension |
| REN | Ringer Equivalence Number |
| RF | Radio Frequency |
| RFI | Radio Frequency Interference |
| RFID | Radio Frequency Identification |
| RHCP | Right Hand Circular Polarisation |
| RIN | Relative Noise Intensity |
| RIP | Routing Information Protocol |
| RISC | Reduced Instruction Set Computer |
| RL | Return Loss |
| RLC | Run Length Coding |
| RLR | Return Loss Ratio |
| RM | Rack Mount |
| RMS | Root Mean Square |
| RMSD | Root Mean Square Deviation |
| RMU | Rack Mounting Unit |
| ROM | Read Only Memory |
| RPC | Remote Procedure Call |
| RR | Ring Return |
| RS | Reed Solomon |
| RSA | Rural Service Area |
| RSL | Received Signal Level |
| RST | Running Status Table (multiplex) |
| RTC | Real Time Clock |
| RTOS | Real Time Operating System |
| RTS | Request To Send |
| RTT | Round Trip Time |
| RTV | Real-Time Video |
| RU | Rack Unit (1.75'high X 19' wide) |
| RX | Receiver |
| RXD | Received Data |
| S/I | Signal to Interference |
| S/N | Signal to Noise Ratio |
| S/PDIF | Sony/Philips Digital Interconnect Format |
| SA | Spatial Activity |
| SACD | Super Audio Compact Disc |
| SAM | Super-rate Adapter Module |
| SAP | Second Audio Program / Service Access Point |
| SAR | Segmentation And Reassembly |
| SAW | Surface Acoustic Wave Filter |
| SB | Signal Battery |
| SBCA | Satellite Broadcasting and Communications Association |
| SBS | Satellite Business Systems |
| SCAI | Switch to Computer Applications Interface |
| SCART | Syndicat des Constructeurs d'Appareils Radior |
| SCC | System Control Computer |
| SCC3 | System Control Card 3 |
| SCD | Specification Control Document, Single Channel Decoder |
| S-CDMA | Synchronous Code Division Multiplex Access |
| SCE | Service Creation Environment |
| SC-FDMA | Single Carrier Frequency Division Multiple Access |
| SCI | Scalable Coherent Interface |
| SCM | Single Carrier Modulation |
| SCN | Serial Control Network |
| SCO | Synchronous Connection Oriented |
| SCP | Service Control Point |
| SCPC | Single Channel Per Carrier |
| SCR | System Clock Reference / Silicon Controlled Rectifier |
| SCSI | Small Computer System Interface |
| SCT | Single Carrier Transcoder, Severe Congestion Threshold |
| SCTE | Society of Cable Telecommunication Engineers |
| SDA | Synchronous Data Adapter |
| SDB | Serial Distribution Bus |
| SDDS | Sony Dynamic Digital Sound |
| SDH | Synchronous Digital Hierarchy |
| SDI | Synchronous Data Interface |
| SDLC | Synchronous Data Link Control |
| SDP | Synchronous Data Processor |
| SDR | Satellite Digital Radio |
| SDS 56 | Switched Data Services (56kbps) |
| SDSL | Single-line Digital Subscriber Line |
| SDT | Service Description Table (multiplex) (part of SI) |
| SDU | Service Data Unit |
| SDV | Switched Digital Video |
| SECAM | Sequential Colour with Memory |
| SF | Superframe Format |
| SFN | Signal Frequency Network |
| SFTP | Shielded Foil Twisted Pair |
| SGDF | Super-Group Distribution Frame |
| SHDL | Symmetrical High Speed Digital Subscriber Line |
| SHL | Studio to Headend Link |
| SHN | Self Healing Network |
| SI | System Information; Service Information; Step Index |
| SIMD | Single Instruction Multiple Data |
| SIMO | Single Input - Multiple Output |
| SIR | Sustained Information Rate |
| SISO | Single Input - Single Output |
| SLC | Subscriber Line Carrier |
| SLIC | Subscriber Line Interface Circuit |
| SLIP | Serial Line Internet Protocol |
| SLM | Signal Level Meter |
| SLS | Single Line Service |
| SM | Single Mode |
| SMATV | Satellite Master Antenna Television System |
| SMD | Surface Mount Device |
| SMDR | Station Message Detail Recording |
| SMDS | Switched Multimegabit Data Service |
| SMF | Single Mode Fibre |
| SML | Service Management Layer |
| SMPS | Switching Mode Power Supply |
| SMPTE | Society of Motion Picture and Television Engineers |
| SMR | Signal to Mask Ratio; Specialized Mobile Radio |
| SMS | Subscriber Management System |
| SMSR | Side Mode Suppression Ratio |
| SMT | Surface Mount Technology |
| SMTP | Simple Mail Transfer Protocol |
| SNA | Systems Network Architecture |
| SNAIP | Simple Network Management Protocol |
| SNG | Satellite News Gathering |
| SNMP | Simple Network Management Protocol |
| SNOC | Satellite Network Operations Center |
| SNR | Signal to Noise Ratio |
| SO | Small Outline (IC Package) |
| SOJ | Small Outline (J-lead) |
| SONET | Synchronous Optical Network |
| SOP | Small Outline Package; Standard Operating Procedure |
| SOT | Small Outline Transistor |
| SPAN | Service and Protocols for Advanced Network |
| SPB | Serial Packet Bus |
| SPC | Statistical Process Control, Super Physical Contact; Stored Program Control |
| SPE | Synchronous Payload Envelope |
| SPECTRE | Special Purpose Extra Resolution for Terrestrial Enhancements |
| SPM | Self-Phase Modulation |
| sps | symbols per second |
| SPST | Single Pole - Single Throw (switch ) |
| SQL | Structured Query Language |
| SRL | Subrate Data Link; Structural Return Loss |
| SRM | Subrate Multiplexer |
| SRS | Subrate Switch |
| SS | Spread Spectrum; Signaling System |
| SSB | Single Sideband Modulation; Star-Star Bus |
| SSCI | Small Computer Systems Interface |
| SSCQE | Single Stimulus Continuous Quality Evaluation |
| SSOP | Shrink Small Outline Package |
| SSP | Service Switching Point |
| SSU | System Synchronization Unit |
| ST | Stuffing Table |
| STB | Set Top Box |
| STC | System Time Clock |
| STDB | Serial Time Distribution Bus |
| STE | Special Test Equipment |
| STERN | System de Television Radio Numerique |
| STL | Studio to Transmitter Link |
| STM-1 | Synchronous Transmission Mode (155.52 Mbit/s) |
| STM-16 | Synchronous Transmission Mode (2.488 Gbit/s) |
| STM-4 | Synchronous Transmission Mode (622.08 Mbit/s) |
| STP | Signaling Transfer Point |
| STS | Synchronous Transport Signal |
| STS1 | 51.84 Mb/s (SONET) |
| STS3c | 155 Mb/s (SONET) |
| STV | Subscription Television |
| SVC | Switched Virtual Circuit |
| S-Video | Separate Video - video interface carrying separate, synchronised signals for luminance (Y) and chrominance (C) information |
| SWR | Standing Wave Ratio |
T-U
| T1 | 1.544 Mb/s |
| T3 | 44.376 Mb/s |
| TA | Terminal Adaptor; Technical Advisory, Temporal Activity |
| TAB | Tape Automated Bonding |
| TAP | Transmission Access Processor, Transmission Access Platform |
| TBD | To Be Defined |
| TC | Transmission Convergence |
| TCC | Telephone Coordinating Circuit |
| TCM | Trellis Coded Modulation |
| TCP/IP | Transmission Control Protocol/Internet Protocol |
| TCS | Transport Control System |
| TDL | Tapped Delay Line |
| TDM | Time Division Multiplexing |
| TDMA | Time Division Multiple Access |
| TDR | Time Domain Reflectometer |
| TDT | Time and Date Table (multiplex) (part of SI); Transparent Digital Modulation |
| TE | Transverse Electric |
| TEM | Transverse Electro-Magnetic |
| TETRA | Terrestrial Trunked Radio |
| TFT | Thin Film Transistor |
| TFTP | Trivial File Transfer Protocol |
| THz | Terahertz |
| TI | Terrestrial Interference |
| TIM | Telephone Interface Module |
| TIPHON | Telecommunications and Internet Protocol Harmonization Over Networks |
| TIRP | T-Link Integrated Receiver |
| T-Link | Transport Link (Data Rate: 270 Mbps) |
| TLP | Transmission Level Point |
| TM | Transverse Magnetic |
| TMC | Traffic Message Channel |
| TMDS | Transition Minimized Differential Signalling |
| TMN | Telecommunications Management Network |
| TMUX | T-Link Multiplexer |
| TNC | Threaded Neil-Councilman Connector |
| TOT | Time Offset Table (part of SI) |
| TPS | Transmission-Parameter Signalling |
| TR | Tip Return; Technical Reference |
| TS | Transport Stream |
| TS0 | Time Slot Zero |
| TSI | Time Slot Interchange |
| TSM | Timeslot 24 Signalling Module |
| TSOP | Thin Small Outline Package |
| TTC | Telephony Transport Converter |
| TTC&M | Telemetry,Tracking, Control and Monitoring function |
| TTL | Transistor-Transistor Logic |
| TTY | TeleTYpe |
| TV | Television |
| TVRO | Television Receive Only |
| TWTA | Travelling Wave Tube Amplifier |
| TX | Transmitter / Telex |
| UAR | Universal Asynchronous Receiver |
| UART | Universal Asynchronous Receiver / Transmitter |
| UBR | Unspecified Bit Rate |
| UCS | Universal Card Slot |
| UDP | Universal Distribution Panel; User Datagram Protocol |
| UDP/IP | User Datagram Protocol / Internet Protocol |
| UEP | Unequal Error Protection |
| UHF | Ultra High Frequency |
| UL | Underwriters Laboratories |
| ULSI | Ultra Large Scale Integration |
| UMS | Umbrella Management System |
| UMTS | Universal Mobile Telecommunications System (3G) |
| UNI | User Network Interface |
| UPS | Uninterruptible Power Supply |
| UPT | Universal Personal Telecommunications |
| UQM | Uplink Quality Monitor |
| URL | Universal Resource Locator |
| USB | Upper Sideband; Universal Serial Bus |
| USP | Universal Services Processor |
| UTOPIA | Universal Test and Operations Interface |
| UTP | Unshielded Twisted Pair |
V-W-X-Y-Z
| V0P | Velocity Of Propagation |
| VAC | Voltage Alternating Current |
| VAD | Video Adaptor Module (Digital) |
| VADIS | Video-Audio Digital Interactive System |
| VAM | Video Adaptor Module |
| VAN | Value Added Network |
| VANC | Voice Activated Network Control |
| VAPN | Virtual Access to Private Networks |
| VBI | Vertical Blanking Interval |
| VBN | Virtual Backbone Network |
| VBR | Variable Bit Rate |
| VC | Virtual Channel |
| VCB | Voice Conference Bridge |
| VCI | Virtual Channel Identifier |
| VCM | Video Compression Module |
| VCO | Voltage-Controlled Oscillator |
| VCR | Video Cassette Recorder |
| VCXO | Voltage Controlled Crystal Oscillator |
| VDB | Video Distribution Bus |
| VDC | Voltage Direct Current |
| VDE | Verband Deutscher Elektrotechniker |
| VDSL | Very high data rate Digital Subscriber Line |
| VDT | Video Dial Tone |
| VDU | Visual Display Unit |
| VF | Voice Frequency |
| VGA | Video Graphics Adaptor |
| VHF | Very High Frequency |
| VI | Virtual Instrument |
| VIRS | Vertical Interval Reference test Signal |
| VITC | Vertical Interval Time Code |
| VITS | Vertical Interval Test Signal |
| VLC | Variable Length Coding |
| VLF | Very Low Frequency |
| VLIW | Very Long Instruction Word |
| VLSI | Very Large Scale Integration |
| VMEbus | VERSAbus-E (IEEE-1014) ( Eurocard ) |
| VOD | Video On Demand |
| VoIP | Voice over Internet Protocol |
| VP | Virtual Path |
| VPI | Virtual Path Identifier |
| VPN | Virtual Private Networks |
| VQFP | Very Thin Quad Pack |
| VR | Velocity Ratio |
| VRQAM | Variable Rate QAM |
| VRU | Voice Response Unit |
| VSAT | Very Small Aperture Terminal |
| VSB | Vestigial Sideband |
| VSN | Virtual Switched Network |
| VSWR | Voltage Standing Wave Ratio |
| VTR | Video Tape Recorder |
| VU | Volume Unit |
| VXIbus | VMEbus Extensions for Instruments |
| WAIS | Wide Area Information Servers |
| WAN | Wide Area Network |
| WAP | Wireless Application Protocol |
| WARC | World Administrative Radio Conference |
| WATS | Wide Area Telecommunications Service |
| WDM | Wavelength Division Multiplex |
| WEEE | Waste from Electrical and Electronic Equipment |
| WiFi | Wireless Fidelity |
| WK | Working Key |
| WMATV | Wireless Master Antenna Television System |
| WPBX | Wireless Private Branch Exchange |
| WSI | Wafer Scale Integration |
| WWW | World Wide Web |
| XMOD | Cross Modulation |
| XTP | Express Transfer Protocol |
| Y/C | Video interface carrying separate, synchronised signals for luminance (Y) and chrominance (C) information |
| YAG | Yttrium Aluminium Garnet |
| YCP | Yellow Condition Propagation |
| ZCO | Zero Crossing Origin |