5ESS 5 Electronic Switching System (Class 5 Switch)

Home , Analog telephone adapter, Category 5 cable, Stored program control

4ESS 4 Electronic Switching System (Class 4 switch)

#5ESS 5 Electronic Switching System (Class 5 switch)

0 or 0- Zero Minus Dialing

0+ Zero Plus Dialing

0++ Zero Plus Plus Dialing

00+ or 00- Double Zero Dialing

1+ One Plus Dialing

100BASE-T Official project name for 100 Mb/s Fast Ethernet

100BASE-T4 100 Mb/s Fast Ethernet using 4-pair Category 3 cable

100BASE-TX 100 Mb/s Fast Ethernet using 2-pair Category 5 cable

100BT 100Base-T Ethernet

100VG-ANY LAN 100 Mb/s LAN using Demand Priority Protocol originally developed by Hewlett Packard and AT&T for Category 3 cable

10BASE-FL An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on 62 5/125-µm fiber optic cable, a baseband medium of 10 Mbps

10BASE-T An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on 24-AWG, unshielded, twisted-pair wiring, a baseband medium of 10 Mbps

10BASE2 An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on thin coaxial cable, a baseband medium of 10 Mbps The maximum segment length is just under 200m (656ft)

10BASE5 An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on twin axial cable, a baseband medium of 10 Mbps The maximum segment length is 500m (1,640ft)

10GbE 10 Gigabit Ethernet

1G 1st Generation wireless

2.5G 2 5 Generation wireless

2.75G 2 75 Generation wireless; humorous nickname for EDGE

23B + D 23 Bearer + 1 Delta Channels

281Q Two Binary, One Quaternary

2B + D 2 Bearer + 1 Delta Channels

2G 2nd Generation Wireless

2W Two-Wire Circuit

3G 3rd Generation wireless

3G.IP Third Generation Internet Protocol Forum

3GPP Third-Generation Partnership Project

3GPP2 Third Generation Partnership Project 2

4ESS 4 Electronic Switching System (Class 4 switch)

4G 4th Generation wireless

4W Four-Wire Circuit

5ESS 5 Electronic Switching System (Class 5 switch)

802.11 Defined by the Institute of Electrical and Electronics Engineers (IEEE), these standards govern the use of wireless LANs

802.3 Defined by the Institute of Electrical and Electronic Engineers (IEEE), these standards govern the use of the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) network access method used by Ethernet networks

802.5 Defined by the Institute of Electrical and Electronics Engineers (IEEE), these standards govern the use of the token ring network access method

822 Abreviation of Internet document RFC 822 (defining e-mail)

A See Ampere (A)

A-Key Authentication Key

A/D Analog-to-digital

ABF Air blown fiber

AC Alternating Current

ACK Abbreviation for the Acknowledge response in data communications

ACM Aluminum conductor material

ACR Attenuation to Crosstalk Ratio ACR is a comparison of signal strength to noise interference and is used as a bandwidth indicator

ADM Add/drop multiplexer

ADSL Asymmetric digital subscriber line

ADSS All-dielectric self-supporting

AEIC Association of Edison Illuminating Companies

AIA Aluminum Interlocked Armor

AIM Advanced Integration Module

AIN Advanced Intelligent Network

AINAP Advanced Intelligent Network Application Protocol

AIOD Automatic Identification of Outward Dialing

AIS 1) Alarm Indication Signal; 2) Automated Information System

AIX Advanced Interactive Executive

AIX 5L See AIX

AL Access Line

AL/MY Acronym for Aluminum Mylar A laminated aluminum and polyester tape used for shielding wires

ALE Automatic Link Establishment

ALU Arithmetic Logic Unit

AM Amplitude Modulation

AMC Administrative Management Complex

AME 1) Automatic Message Exchange; 2) Amplitude Modulation Equivalent

AMI Alternate Mark Inversion

AMIS Audio Messaging Interchange Specification

AMPS 1) Advanced Mobile Phone Service; 2) Automatic Message Processing System

AMR Advance multi Rate Codec

AMTA America mobile Telecommunications Association

AMTS Automated Maritime Telecommunications System

AN Access Node

ANC All Number Calling

ANI Automatic Number Identification

ANSI American National Standards Institution

AOC Active optical cable

AON All-optical network

AP 1) Access Point; 2) Anomalous Popagation

APC 1) Adaptive Predictive Coding; 2) Automatic Power Control

APD Avalanche photodiode

API Application Programming Interface

APIPA Automatic Private IP Addressing

APL Average Picture Level

APLT Advanced Private Line Termination

APNIC Asia Pacific Network Information Centre

APON ATM Passive Optical Network

APPC Advanced Program-to-Program Communication

APPI Advanced Peer-to-Peer Internetworking

APPN Advanced Peer-to-Peer Networking

APS Automatic protection switching

APVD Advanced plasma and vapor deposition

AR Alternate Route

ARA Apple Talk Remote Access

ARD Automatic Ringdown

ARDIS Advanced Radio Data Information System

ARFCN Absolute Radio Frequency Channel Numbers

ARIB Association of Radio Industries and Businesses

ARIN American Registry for Internet Numbers

ARP Address Resolution Protocol

ARPA Advanced Research Projects Agency

ARPANET Advanced Research Projects Agency Network

ARS Automatic Route Selection

ART Audible Ringing Tone

ARU Audible Response Unit

AS Analog Signal

ASA The American Standards Association, former name of ANSI

ASCII American Standard Code for Information Interchange

ASE Amplified spontaneous emission

ASF Active Streaming Format

ASIC Application-Specific Intergraded Circuit

ASME The American Society of Mechanical Engineers

ASOF Application-specific optical fibers

ASP Active Server Page; 2) Adjunct Service Point; 3) Application Service Provider

ASQ American Society for Quality

ASR Automated Speech Recognition

ASTM American Society for Testing and Materials

AT Attenuation

ATA 1) Advanced Technology Attachment; 2) Analog Telephone Adapter

ATAPI Advanced Technology Attachment Packet Interface

ATB All Trunks Busy

ATDM Asynchronous Time-Division Mulitplexing

ATE Automatic test equipment

ATIS Alliance for Telecommunications Industry Solutions

ATM Asynchronous Transfer Mode

ATSC Advanced Television System Committee

ATTIS AT&T Information Systems

ATU ADSL Transceiver Unit

ATU-C ADSL Transceiver Unit-Central Office

ATU-R ADSL Transceiver Unit-Remote

ATV Advanced Television

AU Alternate Use

AUC Authentication Center

AUI Attachment Unit Interface

AVD Alternate Voice Data

AVD Circuits Alternate voice/data circuits

AVL Automatic Vehicle Location

AVVID Architecture for Voice, Video and Integrated Data

AWC Abbreviation for American Wire Gauge A standard measurement of the size of a conductor

AWG America Wire Gauge

AWGN Additive White Gaussian Noise

AWM Designation for Appliance Wiring Material

AX25 Amateur Radio X 25

AXE An open architecture, Ericsson communications platform

B-ISDN Broadband ISDN

B-PON Broadband passive optical network

B.C. Bare Copper

B+S Brown and Sharpe wire gauge, same as AWG

B2B Business-to-Business

B2C Business-to-Business (e-Commerce)

B3ZS Binary/Bipolar with 3 Zero Substitution

B6ZS Binary/Bipolar with 6 Zero Substitution

B8ZS Binary/Bipolar with 8 Zero Substitution

BACP Bandwidth Allocation Control Protocol

BASR Billing Automatic Send/Receive

BBC Broadband Bearer Capability

BBN Bolt, Beranek and Newmam

BCC Block Check Characters

BCCH Broadcast Control Channel

BCD 1) Binary Coded Decimal; 2) Broadcast Content Delivery

BCF Billion Conductor Feet

BCH Broadcast Channels

BCH Code Bose-Chaudhuri-Hocquenghem Code

BCOB Broadband Connection Oriented Bearer

BCOB-A Bearer Class A

BCOB-X Bearer Class X

BCP Basic Call Process

BCSM Basic Call State Model

BDCS Broadband Digital Cross-Connect System

BDSL Broadband DSL

BEC Backward Error Correction

BECN Backward Explicit Congestion Notification

BELR Binary Equivalent Line Rate

BER Bit Error Rate

BERT Bit Error Rate Test/Tester

BETRA Basic Exchange Telecommuncation Radio Service

BEX Broadband Exchange

BI-MMF Bend-insensitive multimode fiber

BIB Backward Indicator Bit

BICC Bearer Independent Call Control

BICI Broadband Inter-Carrier Interface

BICSI Building Industries Consulting Services International

BIF Bend-insensitive fiber

BINHEX Binary Hexadecimal

BIOS Basic Input/Output System

BIP Bit Interleaved Parity

BISDN Broadband Integrated Service Digital Network

Bisync Binary Synchronous Communications

BITS Building Intergrated Timing Supply

BIU Bus Interdace Unit

BLEC Building Local Exchange Carrier

BLER Block Error Rate

BLERT Block Error Rate Test/Tester

BLES Broadband Loop Emulation Services

BNM Broadband Network Module

BOC Bell Operating Company

BootP Bootstrap Protocol

BOP Bit Oriendted Protocol

Bot Short for “robot”

BP 1 Breakeven Point; 2) Bypass

BPDU Bridge Protocol Data Unit

BPF Billion paired feet

BPI Baseline Privacy Interface

Bps 1) Bits Per Second; 2) Bytes Per Second

BPSK Binary Phase Shift Keying

BPV Bipolar Violation

BRA Basic Rate Access

BREW Binary Runtime Environment for Wireless

BRF Bridge Relay Function

BRI Basic Rate Interface

BROUTER A combination bridge and router, performing the functions of both in a single device

BS Base Station

BSA Basic Serving Arrangement

BSC 1) Base Station Controller; 2) Binary Synchronous Communications

BSE Basic Service Element

BSIC Base Station Identity Code

BSN Backward Sequence Number

BSS Base Station System

BT 1) Bandwidth Time Product; 2) Burst Tolerance

BTA Basic Trading Area

BTAM Basic Telecommunication Access Method

BTS Base Transceiver Station

BTU British Thermal Unit The quantity of heat required to raise the temperature of 1 lb of water 1°F

BUS Broadcast and Unknown Server

BW Bandwidth

BWA Broadband Wireless Access

Byte 1) Bit Asynchronous Transmission Entity; 2) Typically a group of eight binary digits

C 1) A structured, procedural programming language; 2) Celsius - A temperature rating system where water freezes at zero degrees and boils at one hundred degrees

C Format A video recording format commonly used in commercial recording

C Symbol Designated for: capacitance, bias supply and centigrade

C-band The C-band is the “conventional” DWDM transmission band, occupying the 1530 to 1565 nm wavelength range, as specified by the ITU-T G 692 Most EDFAs operate in the C-band

C-SJ Same as SJ except extra-flexible conductor

C-SJO Same as SJO except extra-flexible conductor

C.S.A. Canadian Standards Association, a non-profit, independent organization which operates a listing service for electrical and electronic materials and equipment

C.V. Abbreviation for continuous vulcanization

C/I Carrier-to-Interface Ratio

C/N Carrier-to-Noise Ration

CA Conditional Access/Authority

CAC Carrier Access Code

CAD/CAM Computer-Aided Design/Computer-Aided manufacturing See Radiomobile division for more information on AVL

CAI Common Air Interface

CALC Customer Access Line Charge

CALEA Communications Assistance for Law Enforcement Act

CAN Campus Area Network

CAP 1) Carrierless Amplitude and Phase Modulation; 2) Competitive Access Provider

CAPI Common ISDN API

CARS Cable Television Relay Service

CAS Channel-Association Relay Service

CATV Community Antenna Television

CAU Controller Access Unit

CAV Component Analog Video, a three circuit video format where the signal is transmitted in their component form, Luminance (Y) and Color Difference (R-Y and B-Y)

CBCH Cell Broadcast Channel

CBO Rubber insulated Brewery Cord

CBR 1) Committed Bit Rate; 2) Constant Bit Rate

CBT Core-Based Trees

CC 1) Common Carrier; 2) Cost Component; 3) Cross Connection

CCCH Common Control Channel

CCDF Complementary Cumulative Distribution Function

CCH Control Channel

CCIS Common Channel Interoffice Signaling

CCITT International Telephone and Telegraph Consultative Committee An international standards setting body for the telecommunications industry In 1985, the CCITT chartered the TIA/EIA with drafting the 568 Standards we use today

CCLC Carrier Common Line Charge

CCS 1) Centi Common Line Charge; 2) Common Channel Signaling

CCSA Common Control Switching Arrangement

CCTV Closed Circuit Television

CD Chromatic dispersion

CD-ROM Compact Disc, Read-Only-Memory

CDDI Copper Distribution Data Interface

CDF 1) Channel Definition Format; 2) Cumulative Distribution Function

CDG CDMA Development Group

CDM Code Division Multiplex

CDMA Code Division Multiple Access

Cdma2000 1xEV The EV means “Evolution”

Cdma20001xEV-DO The 1xEv-DoO means “1x-Evoltion-Data Optimized” (or Evolution- Data Only)

Cdma20001xEV-DV The EV-DV means “1xEvolution-Data and Voice ”

Cdma20001xRTT The RTT means single carrier Radio Transmission Technology

CDMA3Xrtt Code Division Multiple Access 3-Carrier Radio Transmission Technology cdmaOne® Code Division Multiple Access One

CDP Code Domain Power

CDPD Cellular Domain Power

CDR Call Detail Record

CDV Cell Delay Variation

CDVCC Coded Digital Verification Color Code

CDVT Cell Delay Variation Tolerance

CE Conditioning Equipment

CE Code, CEC Canadian Electrical Code

CEBEC Belgium Approval Agency; Comite Electrotechnique Belge Service de la Marque

CEC Canadian Electrical Code

CEE European Standards Agency; International Commission on Rules for the Approval of Electrical Equipment

CELP Code-Book Excited Linear Predictive

CEN Comite Europeen De Normalisation

CEN/ISSS European Committee for Standardization/ Information Society Standardization System

CES Circuit Emulation Service

CES Internetworking Function See CES-IWF

CES-IWF CES Internetworking Function

CEV Controlled Environmental Vault

CFA 1) Carrier Facility Assignment; 2) Carrier Failure Alarm

CFIN Carrier Frequency Identification Number

CFP C form factor pluggable

CFR Code of Federal Regulations (US)

CFTC Copper From The Curb

CGA Carrier Group Alarm

CGI Common Gateway Interface

CGMP Cisco Group Multicast Protocol

CGSA Cellular Geographic Services Area

CHAP Challenge Handshake Authentication Protocol

CHTML Compact HTML

CI Customer Installation

CIC Carrier Identification Code

CICS Customer Identification Code

CID Customer Information Control System

CIDR Channel Identifier

CIF Common Intermediate Format

CIR Committed Information Rate

CLASS Custom Local Area Signaling Services

CLDC Connected Limited Device Configuration

CLE Customer Located Equipment

CLEC Competitive Local Exchange Carrier

CLEI Common Language Equipment Identifier

CLI Command Line Interface

CLI, CLID Calling Line Identification

CLLI Common Location Language Identifier

CLP Cell Loss Priority

CMA Construction and Maintenance Agreement

CMIP Common Management Information Protocol One of many network management information exchange protocols The current favorite is SNMP

CMR Cellular Mobile Radio

CMRS Commercial Mobile Radio Service

CMS Call Management Service

CMTS Cable Modem Termination System

CNG Comfort Noise Generation

CNI Communication Network Intelligence

CNI, CNID Calling Number Identification

CNR Carrier-to-noise ratio

CO Central Office

COAM Customer Owned And Maintained

COAX Coaxial Cable

COCOT Customer Owned Coin Operated Telephone

CODE 1) A set of unambiguous symbols and rules specifying the way in which data may be represented 2) In data communications, a system of rules and conventions according to which the signals representing data can be formed, transmitted, received and processed

CODEC Compressor/Decompressor

COM Component Object Model

COP Character Oriented Protocol

CORBA Common Object Request Broker Architecture

CORD Center for Occupational Research and Development

COS Class of Service

COT Central Office Terminal

COW Cell Site On Wheels

CP Call-Progress Tones

CP-IWF Customer Premises Interworking Function

CPAKTM A 100-Gb/s C form factor pluggable optical transceiver from Cisco

CPD Call Processing Data

CPE 1) Chlorinated Polyethylene; 2) Customer Premise Equipment

CPL 1) Commercial Private ; 2) Call Processing Language

CPM Continuous Phase Modulation

CPN Calling Party Number

CPNI Calling Party Number Identification

CPS Characters Per Second

CPSB CompactPCI Packet Switching Backplane

CPU Central Processing Unit

CR Custom Record

CRC Cyclic Redundancy Check/Code

CREDFACS Conduit, Raceway, Equipment Ducts, and Facilities

CRIS Customer Record Information System

CRM Customer Relationship Management

CRTP Compressed Real-Time Transmission Protocol

CS 1) Calling Seconds; 2) Carrier System

CS-95 Phelps Dodge High Performance Conductors trade name for extra high strength copper alloy

CS-ACELP Conjugate Structure Algebraic Code Excited Linear Prediction

CSA 1) Carrier Service Area; 2) Canadian Standards Association

CSD Circuit-Switch Data

CSF Cutoff shifted fiber

CSM Central strength member

CSMA Carrier Sense Multiple Access

CSMA/CA See Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

CSMA/CD Carrier Sense Multiple with Collision Detection

CSO Composite second order

CSPDN Circuit Switch Public Data Network

CSPE Insulating and jacketing compound based on chlorosulfonated polyethylene Also known as Hypalon (DuPont registered trademark)

CSRZ Carrier suppressed return-to-zero

CSRZ-DQPSK Carrier suppressed return-to-zero differential quadrature phase shift keying, a technology that makes it possible to generate DWDM signals with bit rates of 100 Gb/s and beyond per channel and transmit them over long distances

CSTA Computer Supported Telephony Application

CSU Channel Service Unit

CSU/DSU Channel Service Unit/ Data Service Unit

CSV Circuit-Switch Voice

CT 1) Computer Telephony; 2) Cross Talk (also XT)

CT-1 Cordless Telephone-First Generation, or any variety of North American, European, and Japanese analog cordless telephone

CT-2 Cordless Telephone-Second Generation, a digital cordless telephone standard generally used in a residential cordless phone, a Telepoint application, or in a small office wireless- public-branch-exchange system CT-2 handsets can initiate, but cannot receive calls

CT2 Cordless Telephone 2 Also written CT-2

CTD Cell Transfer Delay

CTI Computer Telephone Intergration

CTIA 1) Cellular Telecommunications and Internet Association; 2) Cellular Telecommunications Industry Association

CTS 1) Clear To Send; 2) Cordless Telephone System

CTT Click-to-Talk

CTTC Copper To The Curb

CU Control Unit

CUT Coordinated Universal Time

CV Continuous Vulcanization

CW Center wavelength, or continuous wave

CWDM Coarse wavelength division multiplexing

CXC Coaxial Cable, CSA (Canadian Standards Association) Cable Designation

CXR Carrier

D TYPE A description for the 9, 15 and 25 pin connectors widely used for data communications and microcomputer peripherals It looks very loosely like a "D" when viewed vertically

D-1 Format A serial digital recording format

D-2 Format A composite digital recording format

D-3 Format A composite digital recording format

D-AMPS Digital Advanced Mobile Phone System/Service

D.C. Direct Current

D/A Digital-to-analog

DA Distribution Area

DAC 1) Digital to Analog Converter; 2) Discretion Access Control

DACS Digital Access and Cross-Connection System

DAL Dedicated Access Line

DAMA Demand Assigned Multiple Access

DASD Directly Accessible Storage Device IBM’s term for local hard disk

DAT Digital Audio Tape

DAVIC Digital Audio Video Council dB Decibel dB Loss The loss of a signal in a conductor expressed in decibels dB/km 1) See Decibel/kilometer (dB/km); 2) A logarithmic unit describing the ratio of loss of power per kilometer distance These values are always referenced to a specific wavelength, e g , 0 35 dB/km at 1310 nm, and are used by fiber and cable manufacturers to define the optical fiber’s attenuation

DB15 A standardized connector with 15 pins for Ethernet transceivers

DB25 A standardized connector with 25 pins for parallel or serial connections

DB9 A standardized connector with nine pins for token ring and serial connections dBc Decibel Carrier dBd Decibel Dipole

DBFA Dual-band fiber amplifier dBi Decibel Isotropic dBm Decibel Milliwatt

DBMS Data Base Management System

DBN Data Base Node

DBS Direct Broadcast Satellite

DC Direct current

DCA 1) Dynamic Channel Allocation; 2) Defense Communications Agency (Now DISA)

DCB-MHB Digital Video Broadcasting-Multimedia Home Platform

DCC Data communication channel

DCCH Dedicated Control Channel

DCE 1) Data Communications Equipment; 2) Distributed Computing Environment

DCF Dispersion-compensating fiber

DCM Dispersion compensation module

DCN Data Communication Network

DCOM Distributed Component Object Model

DCR Direct current resistance

DCS 1) Defense Communications System; 2) Digital Cross-connection System

DCS 1800 Digital Cordless Standard 1800

DCT 1) Digital Consumer Terminal; 2) Discrete Cosine Transform; 3) Digital European Cordless Telephone/ Telecommunication/ Technology

DDCMP Digital Data Communication Message Protocol

DDD Direct Distance Dialing

DDL 1) Data Definition Language; 2) Data Description Language

DDN Defense Data Network

DDS 1) Dataphone Digital Service; 2) Digital Data Service

DE Discard Eligible

DEK Data Encryption Key

DEMUX Demultiplex

DES Data Encryption Standard

DF Distribution Frame

DFARS Department of Defense Federal Acquisition Regulation Supplement Governs purchases made by the Department of Defense Includes regulations for the purchase of materials made from Specialty Metals (including stainless steel) Often referred to as the “Berry Amendment”

DFB Distributed feedback (laser)

DFE Decision Feedback Equalizer

DFSK Double-frequency shift keying

DFT Discrete Fourier Transform

DGD Differential group delay

DGE Dynamic gain equalizer

DHCP Dynamic Host Configuration Protocol

DHTML Dynamic Hypertext Makeup Language

DIACID A molecule with two carboxylic acid (-COOH) functional groups

Diameter Distance measured across the center of a circle circumscribing the wires of a strand or the strands of a wire rope

DIAMINE A molecule with two amine (-NH2) functional group

DIB Dual-insulated buffer

DID Direct Inward Dialing

DINS Dialed Number Identification Service

DIOL A molecule with two alcohol (-OH) functional groups; also called "dialcohol"

DIP Dual in-line package

DISA 1) Defense Information Systems Agency; 2) Direct Inward System Access

DISC Disconnect Command

DISOSS Distributed Office Support System by IBM

DIW See Network Communications Cable (NCC) and Twisted Pair

DL 1) Dial Level; 2) Downlink

DLC 1) Data Link Control; 2) Digital Loop Carrier

DLCI Data Ling Connection Identifier

DLE Data Link Escaper character

DLL Dynamic Link Library

DLSw Data Ling Switching

DM Delta Modulation

DMA Direct Memory Access

DMD Differential mode delay

DMI Digital Multiplexed Interface

DML Directly-modulated laser

DMOPRP Switch Profile Loading procedure for a Nortel DMS-250 programmable switch, which accomplishes Network Database Updates

DMT 1) Digital Media Platform; 2) Discrete MuiltTone

DMZ Demilitarization Zone

DN Directory Number

DNA Digital Network Architecture

DNC Distributed Network Computing

DNIC Data Network Identification Code

DNPA Data Numbering Plan Area

DNS Domain Name System/ Service/ Server

DOCSIS Data Over Cable Service Interface Specification

DOD Direct Outward Dialing

DOM Document Object Model

DOP Degree of polarization

DOPL Differential optical path loss

DOS Disk Operating System

DP 1) Dial Pulsing; 2) Dialing Plan

DP-QPSK Dual polarization quadrature phase-shift keying

DPCM Differential Pulse-Code Modulation

DPM Digital Phase Modulation

DPNSS Digital Private Network Signaling System Standard

DPSK Differential Phase-Shift Keying

DPSS Diode-pumped solid-state

DQDB Distributed Queue Dual Bus

DQPSK Differential Quadrature Phase-Shift Keying

DRT Plastic range and dryer cord (CSA)

DS 1) Data Set; 2) Direct Sequence; 3) Directory Server; 4) Digital Signal/System/Service

DS-0 (also DSO) Digital Signal Level Zero

DS-1 (also DS1) Digital Signal Level 1

DS-1C (also DS1C) Digital Signal Level 1C

DS-2 (also DS2) Digital Signal Level 2

DS-3 (also DS3) Digital Signal Level 3

DS-x Digital Signal X

DSA 1) Dial Services Assistance; 2) Distributed System Architecture

DSB Double-Sideband transmission

DSB-RC Double-Sideband Reduced Carrier

DSB-SC Double-Sideband Suppressed-Carrier

DSF Dispersion-shifted fiber

DSL Digital Subscriber Line

DSLAM Digital Subscriber Line Access Multiplixer

DSN 1) Defense Switched Network; 2) Distributed System Network

DSP Digital Signal Processing/Processor

DSR Digital Signal Rate

DSS 1) Decision Support Signal; 2) Dial Selective Signaling; 3) Digital Satellite Service; 4) Digital Signature Standard

DSSS Direct Sequence Spread Spectrum

DSU Digital Service Unit

DSX 1 / DSX 3 A DS-1 / DS-3 Cross Connect

DSX-1 DS-1 Cross Connect

DT 1) Data Terminal; 2) Dial Tone

DTAP Direct Transfer Application Part

DTE Data Terminal Equipment

DTMF Dial Tone Multi-Frequency

DTV Digital Television

DTX Discontinuous Transmission

DUA Direct User Agent

DUT Device under test.

DVB Digital Video Broadcasting

DVB Project Digital Video Broadcasting Project

DVD Digital Versatile Disk

DWDM Dense Wave Division Multiplexing

DWLL Fixed-Wireless Local Loop

DWMT Discrete Wavelet Multi-Tone

DWT Discrete Wavelet Transform

DXI Data Exchange Interface

E Voltage, electromotive force

E-band Defined by ITU-T G 692 as “extended” for wavelengths between 1360 and 1460 nm This band includes the high OH peak in single-mode fibers G 652D fiber is designed for transmission within the extended band In FTTx systems, the term can be confused with the enhancement band, which the ITU-T G 983 and G 984 PON FTTx standards define as the wavelengths between 1550 and 1560 nm for RF overlay transmission of video signals

E-Block Carrier A 10-MHz personal-communications-services carrier serving a basic trading area in the 1885-to-1890-MHz frequency range paired with 1965-to-1970-MHz

E-business Electronic Business

E-ISUP Extended-ISUP

E-mail Electronic Mail

E-Netz German name for GMS 1800 network

E-TDMA Extended/Enhanced Time Division Multiple Access

E1 Europa 1 Euproean equivalent to T1 (but higher bandwidth) Also written as E-1

E3 Europa 3 Euproean equivalent to T3 (but higher bandwidth) Also written as E-3

E911 Enhanced 911

E911 POTS Enhanced 911 Plain Old Telephone Service

EA Economic Area

EAL Evolution Assurance Level

EAP Extensible Authentication Protocol

EAS Extended Area Service

EB Exabyte

Eb/N0 Bit Energy-to-Noise Density

EBCDIC Extended Binary Code Decimal Interchange Code

EBONE European Backbone

EBX Embedded Board, eXpandable

EC 1) Coverage; 2) Echo Cancellation; 3) Electronic Commerce; 4) Exchange Character; 5) Electronically Controlled Coupling

ECDSA Elliptic Curve Digital Signature Algorithm

ECH Echo-Cancelled Hybrid

ECIA Electronics Components Industry Association

ECMA European Computer Manufacturers Association

ECSA Exchange Carrier Standards Association

ECTF Enterprise Computer Telephony Forum

ECTFE Ethylene chloro-triflouroethylene (Halar®)

EDA Equipment distribution area

EDFA Erbium-doped fiber amplifier

EDGE Enhances Data rates for GMS Evolution

EDI Electronic Data/Documents Interchange

EDOA Erbium-Doped Optical Amplifier

EDTV Extended Definition Television edu “Education;” one of the top-level Internet domain names

EEE Electronic Equipment Enclosure

EEHO Either End Hop Off

EEMAC Electrical and Electronic Manufacturers Association of Canada (U S counterpart is NEMA)

EEPROM Electrically Erasable Programmable Read-Only Memory

EF Encircled flux

EFCI Explicit Forward Congestion Indication

EFM Ethernet in the first mile

EFR Enhanced Full Rate

EFS Error-Free Seconds

EFT Electronic Funds Transfer

EFTS Abbreviation for Electronic Funds Transfer System

EGP Exterior Gateway Protocol

EHF Extremely High Frequency

EIA Electronic Industry Association

EIA/TIA North American Standards organization

EIA/TIA 568B North American commercial building telecommunications wiring standard

EIA/TIA 569A North American commercial building standard for telecommunications pathways and spaces Its purpose is to standardize specific design and construction practices within and between buildings which are in support of telecommunications media and equipment

EIA/TIA 606 North American administration standard for the telecommunications infrastructure of commercial buildings Its purpose is to provide guidelines for a uniform administration scheme for the cabling infrastructure

EIR Equipment Identity Register

EIRP Effective Isotropic Radiated Power

EISA Extended Industry Standard Architecture An independent alternative to IBM’s Micro-channel for 32 bit computers

EKMS Electronic Key Management System

EKTS Electronic Key Telephone Service

ELEC See EtherLEC

ELED Edge-emitting diode

ELF Extremely Low Frequency

ELINT Electronics Intelligence

ELSEC Electronics Security

EMB Effective modal bandwidth

EMC Electromagnetic Compatibility

EMD Equilibrium modal distribution

EME Electromagnetic Environment

EMF Electromotive force (voltage)

EMI Electromagnetic Interference

EMP Electromagnetic Pulse

EMR Electromagnetic Radiation

EMRC Energy Mines and Resources Canada

EMRP Effective Monopole Radiated Power

EMS 1) Element Management System; 2) Electronic Message System

EMSED Emanations Security

EMTOX Exchanged of Mixed Traffic over X 25

EMV Electromagnetic Vulnerability

EN 50173 The European standard for generic cabling for customer premises

EN 50174 A proposed European cabling systems planning and installation standard developed by CENELEC

ENG Electronic News Gathering

ENQ Enquiry

ENUM Electromagnetic Numbering

EO Electrical–optical

EOC Embedded Operations Channel

EOM End-Of-Message

EOT End-Of-Transmission character

EPA Environmental Protection Agency (US)

EPD 1) Early Packet Discard; 2) Early Path Delay

EPDM Ethylene-propylene-dene monomer rubber

EPON Ethernet PON

EPR Ethylene-propylene copolymer rubber

EPROM Erasable Programmable Read Only Memory

EPSCS Enhanced Private Switched Comms Service

ERK Emergency restoration kit

ERL Echo Return Loss

ERM 1) Enterprise Relationship Management; 2) Enterprise Resource Message System

ERMES European Radio Message System

ERP 1) Effective Radiated Power; 2) Enterprise Resource Planning

ES 1) Errored Second; 2) Expert System

ESC Escape character

ESCON Enterprise System Connection

ESD Electrostatic Discharge

ESDI Enhanced Small Device Interface

ESF Extended Super Frame

ESL Estimated splice loss

ESMR Enhanced Specialized Mobile Radio

ESN Electronic Serial Number

ESS 1) Electronic Switching System; 2) Employee Self-Service

ESTA Australian approval agency, Electricity Trust of South Australia

ETACS Extended Total Access Communications System

ETB End-of-Transmission Block character

ETFE Ethylene tetrafluoroethylene

EtherLEC Ethernet Local Exchange Carrier

ETIS E- and Telecommunications Informatics Services

ETN Electronic Tandem Network

ETP The European Telecommunications Platform

ETPC Electrolytic Tough Pitch Copper

ETSI European Telecommunications Standards Institute

ETX End-of-Text characters

EVC Equivalent voice channels

EVM Error Vector Magnitude

EXZ Excessive Zeroes

F 1) Frequency; 2) Fahrenheit

F.P.A. General Cable's trademark for polyethylene fused to aluminum for use as cable shielding

FAA Federal Aviation Administration

FACCH Fast Associated Control Channel

FACH Forward Access Channel

FAQ Frequently-Asked-Questions

FAT 1) File Allocation Table; 2) Fiber access terminal

FAW Frame Alignment Word

Fax Facsimile

FBC Facilities-Based Carrier

FBG Fiber Bragg grating

FBT Fused biconical taper

FC Fibre Channel

FCC Federal Communications Commission

FCCH Frequently Correction Channel

FCIA Fibre Channel Industry Association

FCIP Fibre Channel over IP

FCS Frame Check Sequence

FD Full Duplex

FDB Fiber demarcation box

FDD Frequency-Division Duplex

FDDI Fiber Distributed Data Interface

FDF Fiber distribution frame

FDH Fiber Distribution Hub

FDI Fiber Distribution Interface

FDM Frequency-Division Mulitplexing

FDMA Frequency-Division Multiple Access

FDU Fiber istribution unit

FEBE Far End Block Error

FEC Forward Error Control/Correction

FEP 1) Front End Processor; 2) Fluorinated Ethylene Propylene

FER Frame Erasure/Error Rate

FET Field effect transistor

FEU Fourty-foot Equivalent Unit (same as two TEU)

FEXT Far End CrossTalk

FFT Fast Fourier Transform

FG Feature Group

FGA Feature Group A (followed by B, C and D

FH Frequency Hopping

FHMA Frequency-Hopping Multiple Access

FHPE Foamed high density polyethylene

FHSS Frequency-Hopping Spread Spectrum

FI Approval agency of Finland; Electrical Inspectorate

FIFM Fiber in the first mile

FIFO First-In, First-Out

FILM Fiber in the last mile

FIPS Federal Information Processing Standard

FIR Finite Impulse Response

FITL Fiber In The Loop

FLOPS Floating-Point Operations per Second

FM Frequency Modulation

FNC Federal Networking Council (formerly FRICC)

FO Common abbreviation for "fiber optic "

FO-2, FO-6 See TIA/IEEE STANDARDS COMMITTEES

FOCIS Fiber Optic Connector Intermateability Standard

FOCS Fiber Optic Communication System

FOIRL Fiber Optic Inter-Repeater Link

FOMA Freedom of Mobile multimedia Access

FOT Fiber Optic Terminal

FOTP Fiber Optic Test Procedures

FOTR Fiber Optic Transceiver

FOTS Fiber Optic Transmission Systems

FP Fabry-Perot (laser)

FPL Designation of cable which meets Vertical Tray flame test for Fire Protection Signaling Systems

FPLMTS Future Public Land Mobile Telecommunications System

FPLP Designation of Plenum Cable which meets Steiner Tunnel Test for Fire Protection Signaling Systems

FPLR Designation of Riser Cable which meets Riser flame test for Fire Protection Signaling Systems

FPS Frames Per Second

FR 1) Frame Relay; 2) Frequency Response

FR-1 A flammability rating established by Underwriters' Laboratories for wires and cables that pass a specially designed vertical flame test This designation has been replaced by VW-1

FRA Fixed-Radio Access

FRAD Frame Relay Access Devise

FRD Fire Retardant

FRF 1) Frame Relay Forum; 2) Free Software Foundation

FRNC Flame Retardant Non Corrosive

FRP Fiberglass Rodent Protection

FRSP Frame Relay Service Provider

FSAN Full Service Access Network

FSK Frequency Shift Keying

FSM Finite State Machine

FSO 1) Foreign Serving Office; 2) Free-Space Optical

FSWDM Full spectrum wavelength division multiplexing

FT 1) Fault Tolerance; 2) Fourier Transform

FTP File Transfer Protocol

FTSA Fiber to Service Area

FTTA Fiber to the Antenna

FTTB Fiber to the Building or Business

FTTC Fiber To The Curb/Cabinet

FTTD Fiber to the Desk

FTTH Fiber To The Home

FTTN Fiber to the Node

FTTO Fiber to the Office

FTTx Fiber to the Premises

FUNI Frame-based ATM User Network Interface

FWD Free World Dialup

FWHM Full width, half maximum

FWM Four wave mixing

FX Foreign Exchange

FXO Foreign Exchange Office

FXS Foreign Exchange Service, Foreign Exchange Station

G round Potential Zero potential with respect to the ground or earth

G-PON Gigabit PON

G.7xx- A family of ITU standards for audio compression

G.dmt ADSL using Discrete Multitone Modulation

G.Lite Universal ADSL (UADSL), DSL Lite or ADSL Lite

G.SHDSL Single paid High-bit-rate Digital Subscriber Line

G/T Antenna Gain-to-Noise-Temperature

GAN Global Area Network

Gb 1) Gigabit; 2) Gigabyte

GbE Gigabit Ethernet

GBH Group Busy Hour

GBIC Gigabit interface converter

Gbps 1) Gigabits per second; 2) Gigabytes per second

GBR The same signals as RGB

GBRS The color signal set that includes Sync

GCAC Generic Connection Admission Control

GCRA Generic Cell Rate Algorithm

GCT Greenwich Civil Time

GD Group delay

GDF Group Distribution Frame

GDP Gateway Discovery Protocol

GEM G-PON encapsulation method

GEO Geostationary/Geosynchronous Earth Orbit

GERAN GSM Edge Radio Access Network

GETS Government Emergency Telecommunications Service

GFF Gain flattening filter

GFP Global Functional Plane

GGP Gateway-to-Gateway Protocol

GGSN Gateway GPRS Support Node

GHOST GSM Hosted SMS Teleservices

GHz Gigahertz

GI-MMF Graded-index multimode fiber

GI-POF Graded-index plastic optical fiber

GIAC Global Information Assurance Certification

Giga One billion (US)

GII Global Information Infrastructure

GIIF Global Integrated Services Digital Network Industry Forum

GIX Global Internet eXchange

GLULAM Synonym for structural-glued-laminated timber

GMCF Global Mobile Commerce

GMII Gigabit MII

GMPCS Global Mobile Personal Communications by Satellite

GMSK Gaussuian Minimum Shift Keying

GMT Greenwich Mean Time

GND Ground

GNU A recursive acronym for “GNU’s Not Unix,” a Unix-like operating system

GOF Graphic Interchange Format

GOS Grade of Service

Gosip Government OIS Procurement

Gov “Government;” one of the top-level Internet domain names

GPIB General purpose interface bus Also known as the IEEE-488 bus One method of providing communication between various test equipment and controllers

GPRS General Packet Radio Service

GPS Global Positioning System

GR-303 Generic Requirement 303

GRE Generic Routing Encapsulation (Crisco invention)

GRIN Gradient index

GRND Ground abbreviated

GS Grade of Service

GSM Global System for Mobile Communication

GSMA Global System for Mobile Association

GSTN General Switched Telephone Network

GT Global Title (SS7) gTLD Generic Top-Level Domain name

GTO Gast tube sign and oil-burner ignition cable 5,000V-15,000V

GTS Global Telecommunications Society

GTT Global Title Translation

GUI Graphical User Interface

H Magnetic Intensity and Henry (a unit of inductance)

H2GT HyperLAN2 Global Forum

HAAT Height Above Average Terrain

HASB High air-speed blown

HC Horizontal cross-connect

HCDS High Capacity Digital Service

HCI Human-Computer Interaction

HCM High-performance voice Compression Modules

HD 1) Half Duplex; 2) Half Distortion

HDA Horizontal distribution area

HDB3 High Density Bipolar Three Zeros Substitution

HDD Hard Disk Drive

HDLC High-Level Data Ling Control

HDML Handheld Device Markup Language

HDPE High-density polyethylene

HDSL High bit-rate Digital Subscriber Line

HDSL-2 2nd generation HDSL

HDTP Handheld Device Transport Protocol

HDTV High Definition Television

HDX Half-Duplex

HEC Header Error Check

HEHO Head End Hop Off

HEMP High-Altitude Electromagnetic Pulse

HEO Highly Elliptical Orbit

HERF Hazards of Electromagnetic Radiation to Fuel

HERO Hazards of Electromagnetic Radiation to Ordnance

HERP Hazards of Electromagnetic Radiation to Personnel

HF High Frequency

HFC Hybrid Fibre Coax

HFDF High-Frequency Distribution Frame

HFOC Hardened fiber-optic connector

HIDS Host-based Intrusion Detected System

HIPPI High performance parallel interface

HIT Induced Electrical Impulse

HLD High-Level Designator

HLL High Level Language

HLR Home Location Registration

HMAC Hash-based Message Authentication Code

HMFOC Hardened multifiber optical connector

HMI Human Machine Interface

HML Multiline Hunt Group

HO-HO Hop-On Hop-Off

HOST Term describing a Host computer A central computer responsible for the control of time- share terminals and other peripherals Usually associated with minicomputers and mainframes

HP Horizontal Pitch

HPCC High-Performance Computing and Communications

HPCS High-Performance Computing System

HPD Rubber and asbestos-insulated heater cord No braid on individual conductors but with braid overall Also made with neoprene insulation and no asbestos or PVC/NBC

HPLMN Home Public Land Mobile Network

HPN Two-conductor, neoprene-insulated heater cord Parallel construction For use in damp locations

HPR High-Performance Routing

HPSK Hybrid Phase Shift Key

HR/DSSS PHY High Rate/Direct Sequence Spread Spectrum Physical Layer

HRFWG Home Radio Frequency Working Group

HRU HDSL Repeater Unit

HS 600V rated Rubber insulated Heater Cord

HSCI High-Speed Communications Interface (Cisco)

HSCSD High Speed Circuit Switched Data

HSJ 300V rated Rubber insulated Heater Cord

HSRP Hot Standby Router Protocol

HSSI High-Speed Serial Interface

HSTR High-speed Token Ring

HTML Hypertext Markup Language

HTTP Hypertext Transfer Protocol

HTTPD Hypertext Transfer Protocol Daemon

HTU-C HDLS Terminal Unit-Central Office

HTU-R HDSL Terminal Unit- Remote

HUB 1 A central point of connection for several circuits 2 A device which electrically converts a logical topology to a different physical topology An ARCNET hub enables physically star- wired nodes to be seen as a logical, token-passing bus Hubs can be active (powered), or passive (non-powered) Active hubs sometimes are capable of allowing longer cabling lengths than passive units

HVAD Hybrid vapor axial deposition

Hz Hertz

I In-Phase

I/O Input/Output

I/O CHANNEL A high-speed bus used to interconnect peripherals with the CPU

I2R Formula for power in watts, where I = current in amperes, R = resistance in ohms Also see Watt

IAB Internet Architecture Board

IABS Integrated Access Billing System

IACS International Annealed Copper Standard

IAD Integrated Access Device

IAEI International Association of Electrical Inspectors

IANA Internet Assigned Number Authority

IBM International Business Machines Corporation

IC Integrated Circuit

ICA International Communications Association

ICANN Internet Corporation for Assigned Names and Numbers

ICAP Interactive Communicating Application

ICC International Color Code Standard for wire jacket colors; Hot=Brown, Neutral=Blue, Ground=Green/Yellow

ICCF Interexchange Carrier Compatibility Forum

ICD Internet Corporation Device

ICEA Abbreviation for Insulated Cable Engineers Association

ICEA S-95-658-1999 Standard for nonshielded power cables rated 2000 volts or less for the distribution of electrical energy covers THHN/THWN, XHHW and RHH/RHW/USE cables

ICMP Internet Control Message Protocol

ICO Intermediate Circular Orbit

ICO RTT ICO

ICP IMA Control Protocol

ICW Internet Call Waiting

ID Internal Diameter

IDC Insulation Displacement Connection iDEN® Integrated Digital Enhanced Network

IDF Intermediate Distribution Frame

IDFT Inverse Discrete Fourier Transform

IDLC Integrated Digital Network

IDN Intergraded Digital Network

IDSL Intergraded Services Digital Subscriber Line

IDT Intergraded Digital Terminal

IEC Interexchange Carrier

IEEE Institute of Electronics Engineers

IEEE 802 IEEE committee to develop LAN standards

IEEE 802.11 Designation for the IEEE subcommittee which is developing the wireless local-area network standard This standard is being formulated to provide interoperability of wireless local-area- network products

IEEE 802.3 Ethernet standards

IEEE 802.X Guidelines describing the physical and data link layers of the OSI network model for various topologies

IETF Internet Engineering Task Force

IF Intermediate Frequency

IFC Intra Fiber Cabling iFCP Internet Fibre Channel Protocol

IFFT Inverse Fast Fourier Transform

IGMP Internet Group Management Protocol

IGP Interior Gateway Protocol

IIS Internet Information Server

IL Insertion Loss.

IL/RL Insertion Loss / Return Loss.

ILD Injection laser diode

ILEC Incumbent Local Exchange Carrier

ILMI Integrated Local Management Interface

ILTA Integrable tunable laser assemblies

IM Instant Messaging

IMA Inverse Multiplexing of ATM

IMAP Internet Message Access Protocol

IMC Internet Mail Consortium

IME Interfacing Management Entity

IMEI International Mobile Equipment Identifier

IMS IP Multimedia Subsystem

IMSA International Municipal Signal Association

IMSI International Mobile Station Identity

IMT Inter-Machine Trunk

IMT-CDMA Multicarrier See cdma2000® 1XRTT

IMT-CDMA Multicarrier 3X See MC-3X

IMT-DS International Mobile Telecommunications Direct Spread

IMT-MC International Mobile Telecommunications Multi-Carrier

IMT-SC International Mobile Telecommunications Single Carrier

IMT-TC International Mobile Telecommunications Time Code

IMTC International Multimedia Telecommunications Consortium

IMTS Improved Mobile Telephone Service

IMX Intelligent Multiservice Switch

IN Intelligent Network

INAP Intelligent Network Application Protocol

InGaAsP Indium gallium arsenide phosphide

INP Interim Number Portability

INTUF International Telecommunications Users Group

IO Information Outlets

IOS Internetworking Operating System

IOT Inter-Office Trunk

IP 1) Interexchange Plant; 2) Internet Protocol

IP PBX Internet Protocol Private Branch Exchange

IP Rating Ingress Protection Rating, a two digit code, and an optional letter, specifying the level of protection from foreign objects with the first digit referring to protection from solids and the second digit referring to protection from liquids The optional letter can be appended to classify only the level of protection against access to hazardous parts by persons or to provide additional information related to the protection of the device

IP SAN Internet Protocol Storage Area Network

IPA Isopropyl alcohol

IPC IPCC Interprocess Communication

IPCEA Insulated Power and Cable Engineers Association

IPL Initial Program Load

Ipsec Internet Protocol Security

IPTV Internet Protocol Television

IPX Internet Packet Exchange

IPXCP IPX Control Protocol

IR Infrared

IRC 1) International Record Carrier; 2) Internet Relay Chart

IrDA Infrared Data Association

IRQ Interrupt ReQuest

IRTF Internet Research Task Force

IS Interim Standard

ISA 1) Industry Standard Architecture; 2) Instrument Society of America

ISAPI Internet Server Application Program Interface

ISC International Sorftswitch Consortium

ISDN Integrated Services Digital Consortium

ISI Inter-Symbol Interference

ISIS Intermediate System-to-Intermediate System

ISMA Internet Streaming Media Alliance

ISO International Standards Organization

ISP Internet Service Provider

ISS Internet Security Scanner

ISV Independent Software Vendor

IT Information Technology

ITAC International Telework Association and Council

ITC Independent Telephone Company

ITG IP Telephony Gateway

ITMC International Test and Maintenance Centers

ITS 1) Information Transport System (for premises systems); 2) Intelligent Transportation System (for highway systems)

ITSP Internet Telephony Service Provider

ITU International Telecommunication Union

ITU-T International Telecommunication Union, Telecommunications Standardization Sector

IVD Inside vapor deposition

IVM Instant Voice Messaging

IVR Interactive Voice Response

IWF Interworking Function

IXC Inter-Exchange Carrier

J/S Jamming to Signal Ratio

J2ME Java 2 Micro Edition

JAIN Java APIs for Integrated Networks

JANET Joint Academic Network

JCC JAIN Call Control

JDBC Java Database Connectivity

JMS Java Message Service

JPEG Joint Photographic Experts Group

JSC Joint Spectrum Center

JSP Java Server Center

JTACS Japanese Total Access Communications System

JTAPI Java Telephony Application Programming Interface

JTIDS Joint Tactical Information Distribution System

JTRB Joint Telecommunications Resources Board

K 1) Kelvin (temperature); 2) Kilobyte; 3) Metric "Kilo" or 1000; 4) Constant used to denote insulation resistance

K-Band radio spectrum in the 18GHz to 27GHz range used by satellite communications systems

KB Kilobyte (1924 bytes)

Kbps Kilobyte (1000s) per second

KCM 1000 circular mils kcmil One thousand circular mils (MCM)

KDC Key Distribution Center

KEK Key-Encrypting-Key

KeV 1000 electron volts

KHz Kilohertz km Kilometer

KPSI Tensile strength in thousands of pounds per square inch

KTS Key Telephone System kV Kilovolt (1000 volts) kVA Kilovoltampere

KWH Kilowatt hours (1000 watt hours)

L Symbol for inductance

L1 and L2 Level 1 and Level 2 memory caches in a computer

L2F Protocol Layer Two Forwarding Protocol

L2TP Layer Two Tunneling Protocol

LAA Longest Available Agent

LAC L2TP access concentrator

LAI Location Area Identity

LAN Local Area Network

LANE LAN Emulation

LANE UNI LANE User-Network Interface

LAP Local Access Provider

LAPB Link Access Protocol/Procedure Balanced

LAPD Link Access Protocol/Procedure on the D Channel

LAPM Link Access Protocol/Procedure for Modems

LASER Light Amplification by Stimulated Emission of Radiation

LAT Local Area Transport

LATA Local Access and Transport Area

LBS Location-Based Services

LC-ATM Label-Controlled ATM interface

LCA Local Calling Area

LCD Liquid Crystal Display

LCI Logical Channel Identifier

LCN Logical Channel Number

LCP Link Control Protocol

LCR Least Cost Routing

LCV Line Code Violation

LD Long Distance

LDAP Lightweight Directory Access Protocol

LDCELP Low-delay CELP

LDIF LDAP Data Interchange Format

LDP Label Distribution Protocol

LDPE Low Density Polyethylene

LDS Local Digital Switch

LEAP Lightweight Extensible Authentication Protocol

LEARP LAN Emulation Address Resolution Protocol

LEC Local Exchange Carrier

LEC BAN Local Exchange Carrier Billing Account Number

LECS LAN Emulation Configuration Server

LED Light-Emitting Diode

LEO Low Earth Orbit

LERG Local Exchange Routing Guide

LES LAN Emulation Server

LFIB Label Forwarding Information Base

LFSR Linear Feedback Shift Register

LGN Logical Group Node

LIA Laser Institute of America

LID Local Injection and Detection

LIS Logical IP Subnet

LL Leased Line

LLC Logical Link Control

LMDS Local Multipoint Distributed Service

LMI Local Management Interface

LNA Low Noise Amplifier

LNP Local Number Portability

LNS Phone lines, “#LNS” means number of lines

LOCA Loss of Coolant Accident

LOF Loss of Frame

LOS 1) Line of Sight; 2) Loss of Signal

LPC Linear Predictive Coding

LRC Longitudinal Redundancy Check

LSA Least Square Approximation

LSB Least Significant Bit

LSO Local Serving Office

LSP Link-State Packet

LSU Logical Storage Unit

LSZH Low Smoke Zero Halogen

LT Line Termination

LTGF Loose Tube Gel Filled

LTU Line Termination Unit

LULT Line Unit LT

LWP Low water peak m Meter mA Milliampere (one-thousandth of an ampere)

MAC Media Access Control

MAE Metropolitan Area Ethernet

MAHO Mobile Assisted Handoff

MAN Metropolitan Area Network

MAP Multiple Application Platform, Linux powered chassis (Viavi); Mobile Application Part.

MARS 1) Mulitcast Address Resolution Server; 2) Mulitcast Address Resolution Server

MASER 1) Microwave Amplification by Stimulated Emission of Radiation

MATV Master Antenna Television System

MAU 1) Media Access Unit; 2) Multistation Access Unit

MB Megabyte

MBone Mulitcast Backbone

Mbps Megabites per second

MBS Macimum Burst Size

MC Main cross-connect

MC-CDMA Multi-Carrier Code Division Multiple Access

MCA Micro-Channel Architecture

MCC 1) Maintenance Control Circuit; 2) Mobile Country Code

MCF Million Conductor Feet

MCIA Native Client Interface Architecture

MCM 1) Multi-Carrier Modulation; 2) One Thousand Circular Mils

MCPC Mode conditioning patchcord

Mcps Mega Chips per Second

MCR Minimum Cell Rate

MCU Multipoint Conferencing Unit

MCVD Modified chemical vapor deposition

MCX Micro Coaxial

MDA Mobile Data Association

MDF 1) Medium Density Fiberboard; 2) Main Distribution Frame

MDPE Medium-density polyethylene

MDSL Multi-Rate Digital Subscriber Line

MDU Multiple Dwelling Unit

MEM Micro-electro-mechanical

MEMS Micro-Electromechanical Sytems

MEO Medium Earth Orbit

MERS Most Economical Route Selection

MeT Mobile Electronic Transactions Limited

MexE Mobile Station Application Execution Environment

MFD Mode-Field Diameter

MFJ Modified Final Judgement

MFRA MPLS and Frame Relay Alliance

MFT One thousand feet

MFU Multiple family unit

MG 1) Master Group; 2) Media Gateway

MGC Media Gateway Controller

MGCP Media Gateway Control Protocol

MH Mobile Host

MHO The unit of conductance equal to the reciprocal of the unit of resistance (ohm)

MHV Miniature High Voltage

MHz Megahertz

MIB Management Information Base

Micro One millionth

MIDP Mobile Information Device Profile

MII Media Independent Interface

MIL 1) Military specification for wire; 2) 0 001" (1/1000 inch) one 1000th of an inch

MIL-DTL-17 DSCC specification for Radio Frequency cables, flexible and semi-rigid

MIL-SPEC United States Defense Standard, often called a military standard, "MIL-STD", or "MIL-SPEC" A MIL-SPEC for quality standards for electronic parts is MIL-STD-202

Milli One-thousandth

MIME Multi-Purpose Internet Mail Extensions

MIN Mobile Identifications Numbers minEMBc Minimum calculated effective modal bandwidth

MiniBNC Miniature bayonet Neill-Concelman

MIPS Million Instructions Per Second

MJ Modular Jack

ML-PPP Multilink PPP

MLM Multilongitudinal mode

MM Mulitmedia Message

MMCX Miniature micro-connector with snap on coupling mechanism

MMDS Mulitchannel Multipoint Distributed Service

MMF Multimode fiber

MMI Man-Machine Interface

MMJ Modified Modular Jack

MMM Mobile Media Mode

MMS Multimedia Messaging Service

MMSE Multimedia Messaging Service Environment

MMTA MultiMedia Telecommunications Association

MNP Microcom Networking Protocol

MP Mulitplexing

MPD Mode power distribution

MPE Multi-Pulse Excited

MPEG Motion Picture Experts Group

MPF Million paired feet

MPLS Multi-Protocol Label Switching

MPO Multifiber push-on connector

MPoA Multi-Protocol Over ATM

MPT Multipoint-to-Point Tunneling

MRB Master Boot Record

MRCL Maximum rated cable load

MRD Manual Ring Down

MRO Maintenance, repair and overhaul

MS Mobile Station

MS-CDMA Mulitband Synchronous DS-CDMA

MS-DOS Microsoft Disk Operating System

MSA 1) Metropolitan Serving Area; 2) Metropolitan Statistical Area

MSAU Multi-Station Access Unit

MSB Most Significant Bit

MSC Mobile Switching Center

MSDS Material safety data sheet

MSG Multiservice Switching Forum

MSIR Microsoft Internet Explorer

MSK Minimum Shift Keying

MSO Multiple System Operator

MSP Managed Service Provider

MSS 1) Mobile Satellite System; 2) Mobile Service Station

MST Multifiber service terminal

MSTP Multiservice transport platform

MT Mobile Terminal

MT-RJ Mechanical transfer registered jack

MTA Major Trading Area

MTBF Mean Time Between Failures

MTDC Multitenant Data Center

MTJ Master Test Jumper, launch and receive test cables, high quality Jumpers used to connect between the MAP/PCT instrument and the DUT.

MTP Message Transfer Part

MTP (MPO) Multi-channel (4 to 72) connector from USConec (MPO is generic version).

MTS Message Telephone/Toll Service

MTSO Mobile Telephone Switching Office

MTTR Mean Time To Repair

MTU 1) Maintenance Termination Unit; 2) Multiple Tenant Unit

MTW Thermoplastic insulated machine tool wire

MU Message Unit

MULTOS Multiple Operating System

MUTOA Multiuser telecommunications outlet assembly

MUX Multiplexer mV Millivolt; One thousandth of a volt

MVL Multiple Virtial Lines

MVT Moisture Vapor Transmission mW Milliwatt; One thousandth of a watt

N-AMPS Narrowband Advanced Mobile Phone Service

N-CDMA Narrowband Code Division Multiple Access

N-ISDN Narrowband Intergrated Service Digital Network

N/mm2 Newtons per squared mm

NA Numerical aperture

NA W-CDMA North American Wideband CDMA

NAA Next Available Agent

NACC North American Color Code; Hot=Black, Neutral=White, Ground=Green

NACN North American Cellular Network

NACS NetWare Asynchronous Communication Services

NADC North America Digital Cellular

NAK Negative Acknowledgement

NAM Number Assignment Module

NANC North American Numbering Council

NANOG North American Network Operator’s Group

NANP North America Numbering Plan

NAP 1) Network Access Point; 2) Network Access Provider

NARUC National Association of Regulatory Utility Commissioners

NAT Network Address Translation

NATA North American Telecommunications Association

NATOA National Asociation of Telecommunications Officers and Advisors

NBH Network Busy Hour

NBMA Mon-Broadcast Multi-Access

NBR Butadiene-acrylonitrile copolymer rubber, a material with good oil and chemical resistance

NBS National Bureau of Standards

NC 1) Network Computer; 2) No Circuit

NC Codes Network Channel Codes

NCAS Non-Call Associated Signaling

NCC Network control center

NCCF Network Communications Control Facility

NCP Network Control Program

NCS Net Control Station

NDIS Network Driver Interface Specifications

NDUB Network-Determined User Busy

NE Network Element

NEBE Near End Block Error

NEBS Network Equipment Building System

NEC National Electric Code

NECA National Exchange Carrier Association

NEMA National Electric Manufacturers Association

NEP Noise Equivalent Power

NESC National Electrical Safety Code

NFPA National Fire Protection Association

NFS Network File System

NGI Next Generation Internet

NGN Next Generation Network

NI Network Interface

NIC Network Interface Card

NIC Code Network Channel Interface Code

NID Network Interface Device

NIOSH National Institute of Occupational Safety and Health

NIST National Institute of Standards and Technology

NIU Network Interface Device

NM Non-metallic sheathed cable, braid or plastic covered For dry use, 60°C

NM-B Non-metallic sheathed cable, plastic covered

NMC Network Management Center

NMS Network Managenent System

NMT Nordic Mobile Telephone

NMTS Nordic Mobile Telephone Service

NMVT Network Mangement Vector Transport

NNI Network-Node interface

NNTP Network News Transfer Protocol

NOC Network Operations Center

NOS Network Operations System

NPF Network Processing Forum nrt-VBR Non Real Time Variable Bit Rate

NRZ Non-Return-to-Zero

NRZ-M Non-Return-to-Zero Mark ns Nanosecond

NSAP Network Service Access Point

NSGR Network Standards Generic Requirements

NSP Network Service Provider

NSS Network Switching Subsystem

NT Network Termination

NTACS Narrowband Total Access Communications System

NTIA National Telecommunications and Information Administration

NTIS National Technical Information Service

NTN 1) National Telecommunications Network; 2) Network Terminal Number

NTP Network Time Protocol

NTSC National Television Standards Committee

NTU Network Termination Unit

NUL Null Character

NVE Network Visible Entity

NVIS Near-Vertical-Incidence Skywave

NXX Network Numbering Exchange

NZ-DSF Non-Zero-Dispersion-Shifted Fiber

OA Optical amplifier

OAC Overlay Area Code

OADM Optical Add Drop Mulitplexer

OAN Optical Access Networking

OAS Office Automation Systems

OC Optical Carrier

OC-n or OCn Optical Carrier Level n Signal

OCDMA Optical code division multiple access

OCQPSK Orthogonal Complex Quadrature Phase Shift Keying

OCR Optical Character Recognition

OCX Object Linking and Embedding (OLE) control

OD Outside Diameter

ODI Open Datalink Interface

ODN Optical Distribution Network

ODU Optical Demultiplexer Unit

OE Optical-to-Electrical

OEE Optical Entrance Enclosure

OEIC Optoelectronic Integrated Circuit

OEM Original Equipment Manufacturer

OEO Optical–electrical–optical

OFCP Optical fiber conductive plenum

OFCR Optical fiber conductive riser

OFDM Orthogonal Frequency-Division Multiplex

OFHC Oxygen-free, high-conductivity copper

OFNP Optical fiber nonconductive plenum

OFNR Optical fiber nonconductive riser

OFSTP Optical fiber system test procedures

OHG Operators Harmonization Group

OHMS A measure of resistance

OI Optical isolator

OLE Object Linking Embedding

OLS Optical line system

OLT Optical line terminal

OLTP Online Transaction Processing

OLTS Optical loss test set

OM Optical multimode

OMA Open Mobile Alliance

OMU Optical multiplexer unit

ONT Optical network terminal

ONU Optical Network Unit

OPA 1) Outside-Premise-Addressability Unit; 2) Online Privacy Alliance

OPGW Optical power ground wire

OPM Optical power meter

OPS Optical protection switch

OPX Off Premises Extension

OQPSK Offset Quadrature Phase Shift Keying

ORB 1) Object Request Broker; 2) Office Repeater Bay org Generic top-level Internet domain name

ORL Optical return loss

OS Operating System

OS/NE Operations System/Network Element

OSA 1) Optical spectrum analyzer; 2) Optical subassembly; 3) Optical Society of America

OSHA Occupational Health and Safety Administration

OSI Model Open System Interconnection Model

OSNR Optical signal-to-noise ratio

OSP Outside plant

OSPF Open Shortest Path System

OSS Operations Support System

OSSI Operations Support System Interface

OTASP Over-The-Air Service Provisioning

OTDM Optical time-division multiplexing

OTDR Optical Time-Domain Reflectometer

OTN Optical transport network

OUT Optical translator unit

OXC Optical cross connect

P2MP Point to multipoint

P2P Point to point

P2P- Peer-to-Peer

PA Power Amplifier

PABX Private Automatic Branch Exchange

PACS Personal Access Communications System

PAD Packet Assembler/Disassembler

PAL 1) Phase Alternation by Line; 2) Public Access Line

PAM Pulse Amplitude Modulation

PAN Personal Area Network

PAP Password Authentication Protocol

PAS Personal Access System

PB Petabyte

PBT Poly-Butylene Terephthalate

PBX Private Branch Exchange

PCB Printed Circuit Board

PCI Peripheral Component Interconnect PC Bus Interface

PCM Pulse Code Modulation

PCT Passive Component Tester, application that runs on MAP.

PCVD Plasma activated chemical vapor deposition

PDA Personal Data Assistant

PDC 1) Pacific Digital Cellular; 2) Personal Digital Cellular

PDF 1) Portable Document Format; 2) Probability Density Function

PDFA Praseodymium-doped fiber amplifier

PDH Plesiosynchronous Digital Hierarchy

PDL Polarized dispersion loss

PDLC Polarization dependent loss compensation

PDM Polarization division multiplexing

PDN Public Data Network

PDS Premise Distribution system

PDU Protocol Dada Unit

PE Polyethylene

PEL Permissible Exposure Limit

PET polyethylene terephthalate pH Measure of Acidity

PIC Primary Interexchange Carrier

PIC Code Pre-subscribed/Primary Inter-LATA Carrier Code

PICMG PCI Industrial Computer Manufacturers Group

PICMG 2.16 PICMG “Ethernet backplane” standards

PICO One-millionth of one-millionth

PIN Positive-intrinsic-negative

PIN-FET Positive-intrinsic-negative field-effect transistor

PING Packet INternet Groper

PINT PSTN/Internet INTernetworking

PKCS Public-Key Cryptography Standards

PKI Public Key Infrastructure

PL Private Line

PLC Packet Loss Concealment

PLI Pounds per linear inch

PLL Phase Locked Loop

PLMN Public Land Mobile Network

PLOAM Physical layer operations, administration, and maintenance

PM Phase Modulation

PM-QPSK Polarization multiplexed quadrature phase shift keying

PMD Polarization mode dispersion

PMDC Polarization mode dispersion compensation

PMR Private Mobile Radio

PNCQPSK Psuedo-Noise Complex Quadrature Phase Shift Keying

PNNI Private Network Node Interface

PnP Plug and Play

POCS Plain Old Cable Service

POF Plastic optical fiber

POI Point of Interface

PON Passive Optical Network

POP Point o Presence

POTP Passive optical transport platform

POTS Plain Old Telephone Service

PP Polypropylene

PPD Partial Packet Discard

PPE Personal protective equipment

PPM Parts per million

PPP Point-to-Point Protocol

PPP/MD Point-to-Point Protocol/Mulitlink Protocol

PPTP Point-to-Point Tunneling Protocol

PRA Primary Rate Access

PRBS Pseudo-Random Binary Sequence

PRI Primary Rate Interface

PRMA Packet Reservation Multiple Access

PROM Programmable Read-Only Memory

PRP Primary Routing Point

PRS Primary Reference Signal

PS polystyrene

PSACR See POWER SUM ATTENUATION TO CROSSTALK RATIO

PSAP Public-Service Answering Point

PSC Public Service Commission

PSD Power Spectral Density

PSI Pounds per square inch psia Pounds per square inch absolute

PSK Phase Shift Keying

PSN 1) Packet-Switching Network; 2) Public Switching Network

PSTN Public Switching Telephone Network

PTFE Polytetrafluoroethylene

PU Physical Unit

PUC Public Utilities Commission

PUC/PSC Public Utility Commission/Public Service Commission

PUR Polyurethane

PVA polyvinyl alcohol

PVC 1) Permanent Virtual Circuit/Connection; 2) Polyvinyl Chloride

PVD Polyvinylidene Fluoride (see also Kynar®)

PVP Permanent Virtual Path

PWM Pulse-Width Modulation

PXC Photonic cross connect

Q Quadrature-Phase

QA Quality Assurance

QAM Quadrature Amplitude Modulation

QC Quality Control

QCIF Quarter Common Interchange Format

QDM Double-band amplitude modulation

QLLC Qualified Logical Link Control

QoS Quality of Service

QPM QoS Policy Manager

QPSK Quadrature Phase-Shift Keying

QRS Quasi-Random Signal

QRSS 1) Quasi-Random Signal Sequence; 2) Quasi-Random Signal Source

QRST Quasi-Random Test Signal

QRW Quasi-Random Word

QSIG Q Signaling

Quad A four conductor cable

QWP Query With Permission

R Interface

RA Remote Access

RACE Research in Advanced Communications Equipment

RACH Random Access Channel

RAN Radio Access Network

RBOC Regional Bell Operating Company

RBS Rated breaking strength

RC 1) Radio Configuration; 2) Rate Center; 3) Repeating Coil

RCC Radio Common Carrier

RCCN Radio Common Carrier Number

RCVR Receiver

RD Resistance Design

RDBMS Radio Data Base Management System

RDRAM Rambus Direct RAM

REA Rural Electrification Administration

REAG Regional Economical Area Grouping

REL Recommended Exposure Limit set by NIOSH

REXX An interpreted script language development by IBM

RF Radio Frequency

RFC Request for Comment

RFI 1) Radio Frequency Interference; 2) Request for Information

RFoG Radio frequency over glass

RFP Request For Proposal

RFQ Request For Quote

RFTS Remote fiber test system

RG/U Radio Government, Universal

RGB (Red, Green and Blue), the basic parallel component set, in which a signal is used for each primary color

RIN Relative intensity noise

RIP Routing Information Protocol

RITL Radio In The Loop

RJ Registered Jack

RJ-11 Registered Jack 11

RJ-45 Registered Jack 45

RL Return Loss.

RLCG Resistance (R, ohms/km), Inductance (L, mH/km), Capacitance (C, nF/km), and Conductance (G, mho/km)

RLE Run Length Encoding

RLIN Return loss of input connector.

RLOUT Return loss of output connector (if measured).

RMII Reduced Media Independent Interface

RML Restricted mode launch

RMON Remote Monitoring

RMS or rms Root-mean-square

ROADM Reconfigurable optical add/drop multiplexer

RoHS European Union directive that stands for "the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment" This directive bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants It went into effect July 1, 2006

ROJ The designation to Remove Outer Jacket

ROM Read-Only Memory

ROSA Receiver optical subassembly

ROW Rights of way

RPC Remote Procedure Call

RPE-LTP Regular Pulse Excited-Long Term Prediction

RRD Revised Resistance Design

RS Recommended Standard

RS-170A The EIA technical standard for NTSC color television

RS-232 Recommenced Standards 232 (Physical interface between DCE and DTE)

RSA Rural Service Area

RSSI Received Signal Strength Indication

RSVP Resource Reservation Protocol

RT Ringback Tone rt-VBR Real-Time Variable Bit Rate

RTCP Real-Time Control Protocol

RTE Real-Time Enterprise

RTM Reference test method

RTMS Radio Telephone Mobile System

RTP Real-Time Transfer Protocol

RTSP Real-Time Streaming Protocol

RTU Remote Termination Unit

RU Rack unit

RUS Rural Utilities Service

Rx Receive or receiver

S S Interface

S-band The frequency spectrum from 2 GHz to 4 GHz used for land based microwave and some mobile satellite communications

S-UMTS Satellite Universal Mobile Telephone System/Standards

S/I Signal-to-Inference Ratio

S/N Signal-to-Noise Ratio

SA Switched Access

SAA Systems Application Architecture

SAC Service Access Code

SACCH Slow Associated Control Channel

SAE Society of Automotive Engineers

SAFT Shear Adhesion Failure Temperature

SALT Speech Application Language Tags

SAM Service Access Multiplexer

SAMA Spread Aloha Multiple Access

SAMM Service Access, Mediation, and Management

SAN Storage area network

SANZ Standards Association of New Zealand

SAP Service Access Point

SAR 1) Specific Absorption Rate; 2) Segmentation and Reassembling

SAT Set-up Audio Tone

SAT-CDMA Satellite-based CDMA

SBC 1) Session Border Controller; 2) Soft bare copper

SBR A copolymer of styrene and butadiene Also GR-S or Buna-S Most commonly used type of synthetic rubber

SBS Stimulated Brillouin scattering

SC 1) Signaling Converter; 2) Switching Center

SCC Specialized Common Carrier

SCCH Signaling Common Channel

SCCP 1) Signaling Connection Control Part; 2) Skinny Client Control Protocol

SCE Service Creation Environment

SCF Service Control Function

SCH Synchronization Channel

SCN Switched Circuit Network

SCP Service Control Point

SCR Sustainable Cell Rate

SCSI Small Computer System Interface

SCTE Society of Cable Telecommunications Engineers

SD Service drop cable

SDARS Satellite Digital Audio Radio Service

SDCCH Slow Dedicated Control Channel

SDH Synchronous Digital Hierarchy

SDK Software Developers’ Kit

SDLC Synchronous Data Link Control

SDM Spatial Division Multiplexing

SDMA Space Division Mulitple Access

SDN Software Defined Network

SDP Session Definition/Description Protocol

SDR Software Defined Radio

SDRF Software Defined Radio Forum

SDSL Symmetric Digital Subscriber Line

SDTV Standard Definition Television

SDU Service Data Unit

SDV Switched digital video

SE Above ground service entrance cable, not protected against mechanical abuse Flame- retardant, moisture-resistant covering Overall neoprene sheath, 60°C-75°C

SECAM Sequential Couleur avec Memoire

SEFT Severely Errored Framing Second

SER Service round entrance cable (Type SE, Style R)

SERDES Serializer/deserializer

SET Secure Electronic Transaction

SEU Service Entrance Cable (type SE, style U) (Unarmored)

SF Super Frame

SFF Small form factor

SFHMA Slow Frequency-Hopped Mulitple Access

SFP Small form factor pluggable

SFS Single-Frequency Signaling

SFTS Single-Frequency and Time Signal

SG Signaling Gateway

SGCP Simple Gateway Control Protocol

SGML Standard Generalized Markup Language

SGNT Special Grade Network Trunked

SGTRAN Signaling Transport

SHDSL See G SHDSL

SHF Super High Frequency

SHR Self-healing ring

SHV Safe High Voltage

SI International System of Units

SIA Steel Interlocked Armor

SIC Specific Inductive Capacity

SID 1) Silence Insertion Descritiptor; 2) Sudden Ionospheric Disturbance

SIGINT Signal Intelligence

SIM Subscriber Identity Module

SIM Card Subscriber Identity Module Care

SIMD Single Instruction Multiple Data

SIMPLE SIP for Instant Messaging and Presence Leveraging Extensions

SIN SIP/IN Internetworking

SIP Session Initiation Protocol

SIP BCP-T SIP Best Common Practice for Telephony

SIP-T Session Initiation Protocol for Telephony

SIP+ Session Initiated Protocol+

SIPPING Session Initiation Protocol Project Investigation

SLA Service Level Agreement

SLC Subscriber-Loop Carrier

SLED Surface-emitting LED

SLEE Service Logic Execution Environment

SLIC Subscriber line interface circuit

SLIP Serial Line Internet Protocol

SLM Single-longitudinal mode (laser)

SMA Subminiature type A connector

SMB Subminiature B

SMC Subminiature C

SMDS Switched Mulitmegabit Data Service

SMF Single-mode fiber

SMFCB Subcarrier Modulated Fibre-Coax Bus

SMG Supermastergroup

SMII Serical MII

SMON Switch Monitor

SMP Symmetric Multiprocessing

SMPE Society of Motion Picture and Television Engineers

SMPTE Society of Motion Picture Television Engineers

SMR Specialized Mobile Radio

SMS Short Message Service

SMSC Short Messaging Service

SMT Surface Mount Technology

SMTP Simple Mail Transfer Protocol

SNA System Network Architecture

SNMP Simple Network Management Protocol

SNR Signal-to-Noise Ratio

SO 1) Service Order; 2) Switching Office

SOA Semiconductor optical amplifier

SOAP Simple Object Access Protocol

SOH Start of Header

SOHO Small Office/Home Office

SONET Synchronous Optical Network

SOP State of polarization

SPARC Sealable Processor Architecture

SPC 1) Stored Program Control; 2) Silver plated copper

SPCW Silver Plated Copper Weld

SPIE Society of Photographic Instrumentation Engineers

SPIRITS Services in the PSTN/IN Requesting Internet Services

SPM Self phase modulation

SQA Software Quality Assurance

SQL Structured Query Language

SR Spread Rate

SRAM Static RAM

SRD Portable range or dryer cable

SS 1) Spread Spectrum; 2) Supervisory Signal

SSB Single Sideband Radio

SSCOP Service Specific Connection Oriented Protocol

SSD Shared Secret Data

SSID Service Set Identifier

SSMA Sub-Subminiature A

SSP Service Switching Point

STB Set-Top Box

STD Selective Transmit Diversity

STEL Short term exposure limit

STM Synchronous Transfer Mode

STP Shielding Twisted Pair

STS 1) Serving Translation Scheme; 2) Shared Tenant Service; 3) Synchronous Translations Scheme

STS-n Synchronous Transport Signal-n

STW Hard usage cord, jacketed

STX Start Of Text

SU Service User

SVC Switched Virtual Circuit

SVOD Switched video on demand

SW-CDMA Satellite-based Wideband CDMA

SW1 Switch connected to output J1.

SW2 Switch connected to J2 or to Detector.

SWC Service Wire Center

SWR Standing Wave Ratio

SX Simplex Signaling

SYSGEN System Generation

T Interface (between ISDN NT1 and NT2)

T.120 An ITU-T standard for document conferencing

T.30 International standard protocol for standard transmission of taxes, originally meant for circuit- switched lines

T.37 Standard for store-and –forward FoIP (Fax-over-IP)

T.38 Standard for real-time FoIP (Fax-over-IP)

T1 Tier 1 T-Carrier

T1C Tier 1C = DS1c-formatted (concatenated) digital signal at 3 153 Mbps ; the equivalent of 48 voice channel

T2 Tier 2 = DS-2-formatted digital carrier signal at 6 312 Mbps ; the equivalent of 94 voice channel

T3 1) Tier 3

TABS Telemetry Asynchronous Block Serial

TACACS Terminal Access Controller Access Control System

TACS Total Access Communications System

TADIL Tactical Data Information Link

TAI Temporary Mobile Station Identity

TAPI Telephony Application Program Interface

TARP TID Address Resolution Protocol

TASI Time-Assignment Speech Interpolation

TAT Trans-Atlantic Telecommunications (cable)

TAXI Transparent asynchronous transmitter receiver interface

TB 1) Terabyte; 2) Terminal Block

TBD To Be Determined

TBOS Protocol-Telemetry Byte-Oriented Serial Protocol

TC 1) Telephony Controller; 2) Traffic Contact; 3) Toll Center

TCA Telecommunications Access

TCAM Telecommunications Access Method

TCAP Transaction Capability Application Part

TCF Technical Control Facility

TCH Traffic Channel

TCIF Telecommunications Industry Forum

TCM 1) Time Compression Multiplexing; 2) Trellis Code Modulation

TCP Transmission Control Protocol

TCP/IP Transmission Control Protocol/Internet Protocol

TD-SCDMA Time Division Synchronous CDMA

TDD 1) Telecommunication Device for the Deaf; 2) Time Division Duplex

TDM Time Division Multiplexer/Multiplexing

TDMA Time Division Multiple Access

TDN Temporary Directory Number

TDR Time Domain Reflectometry/ Time Domain Reflectometer

TDTD Time Division Transmit Diversity

TE ISDN Terminal Equipment

TE1 ISDN Terminal Equipment Type 1

TEC Thermoelectric cooler

TED Trunk Encryption Device

TEHO Tail End Hop Off

TEK Traffic Encryption Key

TEM Telecom Equipment Manufacturer

TETRA Trans-European Trunked Radio Access

TEW Canadian Standard Association type appliance wires

TFE Teflon (tetrafluoroethylene)

TFFN Fixture wire, thermoplastic-covered with flexible stranding and nylon sheath, 90°C dry

TFTP Trivial File Transfer Protocol

Tg Glass transition temperature below which a polymer is a hard glassy material

TGW Trunking Gateway

TH Transmission Header

THHN 90°C, 600 V nylon jacketed building wire

THICKNET IEEE 802 3 10BASE-5 systems

THIN ETHERNET 10BASE-2 system

THz Terahertz

TIA Telecommunications Industry Association

TIC Token-Ring Interface Coupler

TID 1) Terminal Identifier; 2) Tunnel Identifier

TINA Consortiun Telecommunications Information Networking Architecture Consortium

TIRKS Trunk Integrated Records Keeping System

TKIP Temporal key Integrity Protocol

TL Transmission Level

TLD Top-Level Domain

TLS Transport Layer Security

TLV Threshold Limit Value set by the ACGIH

TM 1) Traffic Management; 2) Melting Temperature

TM Forum Telemanagement Forum

TMC Traffic management center

TMN Telecommunications Managenment Network

TMRS Traffic Measurement And Recording Systems

TNC Threaded Neill Concelman

TO Toll Office

TOP Technical Office Protocol

TOS Type of Service

TOSA Transmitter optical subassembly

TP Tunneling Protocol

TPON Telephony over Passive Optical Network

TR Toll Restriction

TSAPI Telephony Services Application Programming Interface

TSCA Toxic Substance Control Act

TSGR Transport Systems Generic Requirements

TSP Telecommunications Service Priority Service

TSPS Traffic Service Position System

TSS Tandem Switching System

TSTD Time Switched Transmit Diversity

TT Trunk Type

TTA Telecommunications Technology Association

TTC Telecommunications Technology Priority Service

TTL Transistor-transistor logic

TTS Text-to-Speech

TTTN Tandem Tie Trunk Network

TTY Teletypewriter

TUR Trunk Utilization Report

TVoIP TV over IP

TW Thermoplastic vinyl-jacketed building wire

TWA Time weighted average

TX/RX Transmit/Receive

U A vertical unit of measurement (1 75 inches)

UA User Agent

UAC User Agent Client

UADSL Universal ADSL

UART Universal Asychronous Reveiver/Transmitter

UAS User Agent Server

UCLC Universal Digital Channel

UDP User Datagram Protocol

UF Thermoplastic underground feeder and branch circuit cable

UFB Underground feeder cable

UG Universal Government

UHDTV Ultra high definition television

UHF Ultra High Frequency

UI Unit Interval

UIM Usre Idnetity Module

UL 1) Underwriter’s Laboratories; 2) Uplink (Also written as U/L)

ULF Ultra Low Frequency

ULP Upper-Layer Protocol

UMTS Universal Mobile Telephone System/Standard

UNE Unbundled Element

UNI User Network Interface

UNNI Unlicensed National Information Infrastructure

UPC Specific fiber optic contact polishing protocol (process), yielding improved return loss

UPN User Provided Number

UPnP Universal Plug and Play

UPS Uninterruptible Power Supply

UPT Universal Personal Telecommunications

URI Uniform Resource Identifier

URL Uniform Resource Locator

USART Universal Synchronous/Asynchronous Receiver Transmitter

USASI United States of America Standards Institute—now called ANSI (American National Standards Institute)

USB Universal Serial Bus

USE Underground Service Entrance Cable

USTA United Stated Telephone Association

UT Universal Time

UTC Coordinated Universal Time

UTP Unshielded Twisted Pair

UTRA UMTS Terrestrial Radio Access

UUCP UNIX-to-UNIX Copy Protocol

UUT Unit Under Test

UV Ultraviolet Light

UVM-C Universal Voice Module-Channelized

UVM-U Universal Voice Module-Unchannelized

UWB Ultra Wide Band

UWC Universal Wireless Consortium

UWCC Universal Wireless Communications Consortium

V 1) Interface (between an ISDN ET and LT or LE); 2) Vertical side of MDF; 3) Volt

VA Volt Ampere

VAC Volts Alternating Current

VAD Voice Activity Detection, Voice Activity Detector

VADSL Very High Speed ADSL

VAN Value Added Network

VANS Value-Added Network Service

VAR Value-Added Reseller

VARS Volt-Amperes Reactive

VB Visual Basic

VBR Variable Bit Rate

VBScript Visual Basic Script

VC 1) Virtual Channel; 2) Virtual Circuit

VCA Voice Connecting Arrangement

VCC Virtual Channel Connection, Virtual Circuit Channel

VCD Virtual Circuit Descriptor

VCI Virtual Channel Identifier

VCL Virtual Channel Link

VCSEL Vertical-Cavity Surface-Emitting Laser

VDA Video Distribution Amplifier

VDT Video/Visual Display Terminal

VDU Video/Visual Display Unit

VF Voice Frequency

VFC Voice frequency channels

VFCT Voice Frequency Carrier Telegraph

VFTG Voice Frequency Telegraph

VG Voice Grade

VGF Voice Grade Facility

VHE Virtual Time Environment

VHF Very High Frequency

VHSLD Very-High bit rate Digital Subscriber Line

VIP Video Information Provider

VITA VMEbus International Trade Association

VLAN Virtual LAN

VLF Very Low Frequency

VLR Visitor Location Register

VMOA Voice and Multimedia over ATM

VNL Via Net Loss

VOA Variable optical attenuator

VoATM Voice over Asynchronous Transfer Mode

VoB Voice over Broadband

VOC Volatile Organic Compound

VoCable Voice over Cable

VOD Video On Demand

Vodas Voice-Operated Device Anti-Sing

VoDSL Voice over Digital Subscriber Line

VoE Voice over Ethernet

VoFr Voice Over Frame Relay

Vogad Voice-Operated Gain-Adjusting Device

VoHDLC Voice over DLC

VoIP Voice Over Internet Protocol

Volt Standard Unit of Electromotive Force or Electrical Pressure

VoMBN Voice over Multiservice Broadband Network

VON® Voice on the Net

VON® Coalition Voice on the Net Coalition

VoP Voice over Packet

VoWiFi Voice over WiFi

VoWIP Voice over Wireless IP

VoWLAN Voice over Wireless Local Area Network

VoWLL Voice over Wirless Local Loop

VP Virtial Path

VPC Virtial Path Connection

VPDN Virtial Private Dial-up Netwrok

VPI Virtual Path Connection

VPIM Voice Profile for Internet Messaging

VPML Virtual Reality Modeling Language

VPN Virtual Path Identifier

VPON Video passive optical network

VRU Voice Response Unit

VSAT Very Small Aperture Terminal

VSB Vestigial Sideband

VSELP Vector Sum Excited Linear Predictive

VSPT Voice Services Provisioning Tool

VSWR Voltage Standing Wave Ratio

VT 1) Virtual Terminal; 2) Virtual Tributary

VT-n Virtual Tributary Level N

VTAM Virtual Telecommunications Access Method

VtoA Voice and Telephony over ATM

VTP Virtual Terminal Protocol

VTR Video Tape Recorder, an electro-mechanical device that records, stores and reproduces an electronic signal that contains audio, video and control information

VTU Video Teleconferencing Unit

VTU-C VDSL Transmission Unit Central Office

VU Volume Unit

W Watt or Wattage

W-CDMA Wideband Code Division Multiple Access

W/O/G Without ground

W3C W3 Consortium

WA Work area

WAIS Wide Area Information Server

WAN Wide Area Network

WAP Wireless Application Protocol

WARC World Administrative Radio Conference/Consortium

WASP Wireless Application Service Provider

WATS Wide Area Telecommunications Service

WB Wideband

WBMP Wireless Bitmap

WC Wire Center

WCA Wireless Communications Association

WCS Wireless Communications Services

WDM Wavelength Division Multiplexing

WDM-PON Defined by FSAN as a next generation (NG2) network in which each subscriber is assigned their own wavelength

WECA Wireless Ethernet Compatibility Alliance

WEP Wired Equivalent Privacy

WGQ Weighted Fair Queuing

WHMIS Workplace Hazardous Material Information System

WIC Wavelength independent coupler

WiFi Wireless Fidelity

WiMAX Worldwide Interoperability for Microwave Access, also know as IEEE 802 16

WIMS W-C Wireless Mulitmeda and Messaging Services Wideband CDM

WIN Wireless Intelligent Network

WISP Wireless Local Service Provider

WLAM Wireless Local Area Network

WLL Wireless Local Loop Sometimes called Radio in the Loop, Fixed Radio Access to Fixed Wireless Local Loop

WLNP Wireless Local Number Portability

WM Wireless Instant Messaging

WML Wireless Markup Language

WMLScript Wireless Markup Language Script

WORD Number of bits transmitted in parallel on a data bus

WOS Wireless Office Systems

WPA WiFi Protected Access

WPABX Wireless Private Automatic Branch Exchange

WPAN Wireless Personal Area Network

WPCDMA Wideband Packet Code Division Multiplex Access

WRC World Radiocommunication Conference

WRED Weighted Random Early Detection

WSS Wavelength selectable switch

WTLS Wireless Transport Layer Security

WWAN Wireless Wide Area Network

WWMCS Worldwide Military Command and Control System

WWW World Wide Web

WXC Wavelength cross connect

X Variable for Electrical Reactance

XC Cross-Connect

XFP 10 Gigabit small form factor pluggable

XHTML Extensible Hypertext Markup Language

XLP Cross-linked polyethylene

XMD 10 Gb/s miniature device

XMISSION Transmission

XMIT Transmit

XML Extensible Markup Language

Xmodem File transfer protocol

XO Crystal Oscillator

XOFF ASCII Transmitter Off Character

XON ASCII Transmitter On Character

XPM Cross phase modulation

XT Crosstalk

Z Variable for Electrical Impedance

ZBTSI Zero Byte Time Slot Interchange

ZDA Zone Distribution Area

ZWP Zero Water Peak