10-GigE - 10-Gigabit Ethernet 1xEV-DO - 1x Evolution for Data Optimized3GPP - Third-Generation Partnership Project3GPP2 - Third Generation Partnership Project 24G - Fourth Generation wireless systemsA&C - Access and ControlA/NM Administration/Network ManagementA/V - Audio/VideoAA - Associate AdministratorAAA - Authentication, Authorization and AccountingAADS - Ameritech Advanced Data ServicesAAF - Army Air FieldAAL1 - ATM Adaptation Layer 1AARNET - Australian Academic & Research NetworkAAS - Adaptive Antenna SystemAATT - Advanced Aircraft Transportations TechnologiesABM - Asynchronous Balanced ModeABQP - Aggregate Base Station Subsystem Quality of Service ProfileAC - Access ClassAC - Authentication Center ACC - Automatic Congestion ControlACD - Active Circuits DirectoryACE - Advanced Composition ExplorerACI - Adjacent Channel InterferenceACIR - Adjacent Channel Interference RatioACK - Acknowledge or AcknowledgementACK - ACKnowledgmentACL - Access Control ListACLR - Adjacent Channel Leakage RatioACM - Attitude Control MotorACMS - Automated Communications Management System ACO - Access Control OfficerACRR - Adjacent Channel Rejection RatioACS - Adjacent Channel SelectivityACTD - Advanced Concept Technology Demonstration AD - Active DirectoryADC - Analogue to Digital ConverterADD - Architecture Description DocumentADIMSS - Advanced DSN Integrated Management Support SystemADM - Add Drop MultiplexADM - Asynchronous Disconnected ModeADSL - Asymmetric Digital Subscriber LineAEHF - Advanced Extremely High Frequency AES - Advance Encryption SystemAES - Advanced Encryption StandardAF - Application FunctionAF - Assured ForwardingAFB - Air Force BaseAFI - - Air Force InstructionAFIP - Armed Forces Institute of PathologyAFIS - American Forces Information ServicesAFMAN - Air Force ManualAFNOC - Air Force Network Operations Center

AFSCN - Air Force Satellite Control Network AG - Access GatewayAGMEMS - AT&T Government Markets Enterprise Management SystemAGS - Poker Flat Research RangeaGW - access gateway AHAMS - Automated Health and Morale SystemAIDE - Automated Intrusion Detection EnvironmentAIS - Alarm Indication SignalAIS - Automated Information SystemAIS-L - Line AISAIS-P - STS Path AISAIS-V - VT Path AISAKA - Authentication and Key AgreementALA - Active Line AccessALHAT - Autonomous Landing and Hazard Avoidance TechnologyALIT - Automatic Line Insulation TestALNP - Aggregated Line and Node ProtectionAM - Acknowledged ModeAM - Acknowledged ModeAMA - Automatic Message AccountingAMBR - Aggregate Maximum Bit rateAMBR - Aggregated Maximum Bit-RateAMC - Adaptive Modulation and CodingAMC - Adaptive Modulation and CodingAMD - Acknowledged Mode DataAMN - Artificial Mains NetworkAMO - Advanced Modeling Object (GRANITE)AMR - Adaptive Multi-RateAMR - Automatic Meter Reading AMX - AMX is the name of a company now known as PanjaAN - Access NetworkANC - Active Nutation Control ANDVT Advanced Narrowband Digital-Voice TerminalANI - Automatic Number IdentificationANR - Automatic Neighbour RelationANRF - automatic neighbor relation functionANSI - American National Standards InstituteANTL - NREN Laboratory at ARCAO - Area of OperationsAOPNS - Activity & Outage Posting & Notification SystemAOR - Area of ResponsibilityAP - Access Point AP - Application ProtocolAP - Application ProtocolAPAN - Asian Pacific Area NetworkAPAS - Androgynous Peripheral Assembly SystemAPC - Adaptive Protective CodingAPC - Hardware - Advanced processed controlAPC - Vendor - American Power ConversionAPCP - Application Protection Constraint PolicyAPD - Avalanche Photo-Diode APDA - Androgynous Peripheral Docking AssemblyAPI - applications programming interface APL - Applied Physics Laboratory

APL - Approved Product(s) ListAPN - Access Point NameAPP - Application LayerAPP - Application Layer, Application Services LayerAPS - Automatic Protection SwitchingAPS - reference ECANS projectAPU - Auxiliary Power UnitAR&D - Automated Rendezvous & DockingARC - American Red CrossARC - Ames Research CenterARFCN - Absolute Radio Frequency Channel NumberARI - Accessibility/Retainability/IntegrityARIB - Association of Radio Industries and BusinessesARIN - American Registry for Internet NumbersARO - Authorized Requesting OfficialARP - Address Resolution ProtocolARP - Allocation and Retention PriorityARQ - Automatic Repeat RequestARQ - Automatic Repeat reQuestARSTRAT - Army Forces Strategic Command (see SMDC/ARSTRAT) ARTS - Assured Real Time ServicesARTS-SS - Assured Real Time Services SoftSwitchAS - Access StratumAS - Access StratumAS - Angular SpreadAS-SIP - Assured Service Session Control ProtocolASA - Automatic Security AuthenticationASAC - Assured Service Admission Control ASAP - As soon as possibleASCC - Academia Sinica Computing CentreASCLAN - Assured Services Converged Local Area NetworkASIC - Application Specific Integrated Circuit ASLAN - Assured Service LANASME - Access Security Management EntityASN - Autonomous System NumberASN.1 - Abstract Syntax Notation 1ASP - Active Server Pages (web-scripting developed by Microsoft)ASP - Application Server Process ASP - Application Service ProviderASP - Attached Satellite PayloadASRS - Automated Support Requirement SystemASU - Arizona State UniversityATC - Authority to ConnectATCS - Active Thermal Control SystemATIS - Alliance for Telecommunications Industry Solutions ATM - Asynchronous Transfer Mode ATO - Authority to OperateATT - AttenuatorAU - Administrative UnitAUC - authentication centerAUTOVON - Automatic Voice NetworkAVC - Advanced Video CodingAWGN - Additive White Gaussian NoiseAWINS - Agency Widows Internet Naming Services

AXT - Alien Crosstalk B-ONT - business optical network terminal B/P/C/S - Base/Post/Camp/StationB2BUA - Back-to-Back User AgentBA - Billing AgentBAA - Broad Agency AnnouncementBADD - Battlefield Awareness Data DisseminationBAF - Billing AMA FormatBASP - Ball AeroSpaceBBC - British Broadcasting CorporationBBE - Background Block ErrorBBER - Background Block Error RatioBC - Boundary ControllerBCC - Base station Colour CodeBCCH - Broadcast Control CHannelBCH - Broadcast CHannelBCH - Broadcast ChannelBCM - Bearer Control ModeBCT - Brigade Combat TeamBCU - Booster Controller Unit/Booster Control UnitBE - Block ErrorBEM - Bandwidth Efficient Modem BER - Bit Error RateBERK - University of California, BerkeleyBFP - Branch Flow PointBFS - reference ECANS projectBGP - Border Gateway ProtocolBI - Backoff IndicatorBID - Bridge IDBIDWH - Business Intelligence & Data WareHouseBIND - Berkeley Internet Name Daemon BIP - Bit Interleaved ParityBITS - Building Integrated Timing SupplyBLDR - University of Colorado at BoulderBLER - Block Error RateBLER - Block Error RateBLOS - Bigelow Laboratory for Ocean SciencesBLSR - Bidirectional Line-Switched RingBM-SC - Broadcast-Multicast Service CentreBMC - Company that provides Remedy SoftwareBMC - Name of CompanyBMCC - Boeing Mission Control Center, El Segundo, CABNCC - Base Network Control CenterBO - Business Object DatabaseBP - Bandwidth PartBP - Bandwidth ProfileBPA - Blocked Precedence AnnouncementBPC - Boost Protective CoverBPDU - Bridge Protocol Data Unit(s)BPL - Broadband Power Line Communications BPSK - Binary Phase Shift KeyingBPSK - Binary Phase Shift Keying modulationBR-FP - Branch Flow PointBRAS - Broadband Remote Access Server

BRI - Basic Rate InterfaceBS - Base StationBSC - base station controller BSIC - Base Station Identification CodeBSM - Booster Separation MotorBSR - Buffer Status ReportBSS - Base Station SubsystemBSS - Business Support SystemBSTU - Base SHDSL Termination UnitBTA - Business Transformation AgencyBTP - backhaul transport provider BTS - Base Transceiver StationBVI - Bridge Virtual InterfaceBW - BandWidthBWP - BandWidth ProfileBYOB - Bring Your Own BehaviourBYOD - Bring Your Own DeviceC&A - Certification and AccreditationC&T Networks - Command & TelemetryC-RNTI - Cell Radio Network Temporary IdentityC-SAFS - Central Standard Autonomous File Server C-VLAN - Customer VLANC/S/A - COCOM / Service / Agency C/S/A - Combatant Commands, Services, and AgenciesC2 - Command and ControlC3 Command, Control, and CommunicationsC3I - Command, Control, Communications, and IntelligenceC3I - Communication, Command, Control & InformationC4I - Command, Control, Communications, Computers, and IntelligenceC4ISR - Command, Control, Communications, Computers, Intelligence, Surveillance & ReconnaissanceCA - Certificate AuthorityCA - Certification AuthorityCAAP - Critical Asset Assurance ProgramCAC - Call Admission ControlCAC - Common Access CardCAD - Computer Aided DesignCAGR - Cumulative Average Growth Rate CAIL - reference ECANS projectCaLV - Cargo Launch VehicleCAMB - Cambridge, MACAN - Campus Area NetworkCANET*4 - Canadian Research Network - Autonomous System Number (ASN) 4CANF - Cancel FromCANT - Cancel ToCAP - Command and Attitude ProcessorCARD - Constellation Architecture Description DocumentCAS - Conditional Access System - content protection [IPTV] see DRMCAS - Channel Associated SignalingCASI - Center for Aerospace InformationCAT - CategoryCAT - Crisis Action TeamCAT7 - Category 7 cable CATV - Cable Television

CAW - Certificate Authority WorkstationCAZAC - Constant Amplitude Zero Auto-CorrelationCB - Circular BufferCBACS - Center Badging and Access Control SystemCBC - Cell Broadcast CentreCBE - Cell Broadcast EntityCBE - Current Best EstimateCBH - Cell BackHaulCBS - Cell Broadcast ServiceCBS - Committed Burst SizeCBT - Computer Based TrainingCC - Combatant CommanderCC - Convolutional CodeCCA - C3I Communications AdaptorCCA - Call Connection AgentCCB - Configuration Control BoardCCB - Configuration Control BoardsCCCH - Common Control CHannelCCE - Control Channel ElementCCIR - Critical Command Intelligence RequirementsCCM - Continuity Check MessageCCO - Cell Change OrderCCS - Cambridge Communications Systems (small cell backhaul product)CCS - Common Channel SignalingCCSA - China Communications Standards AssociationCCSD - command communications service designatorCCV - Common Communications Vehicle CD - Chromatic Dispersion CD - Conversion DeviceCDATA - (unparsed) Character DATA [ XML (#CDATA) ]CD&SC - Communications Distribution and Switching CenterCDD - Cyclic Delay DiversityCDF - Cumulative Distribution FunctionCDL - Clustered Delay LineCDM - Code Division Multiplex(ed/ing)CDMA - Code Division Multiple AccessCDMGR - Conversion Device ManagerCDN - Coupling/Decoupling NetworkCDP - Commander's Dissemination PolicyCDR - Call Detail RecordingCDR - Critical Design ReviewCDRM - Conceptual Data Reference ModelCDSCC - Canberra Deep Space Control CenterCDTI - Comsat Digital Teleport IncorporatedCE - Carrier EthernetCE - Circuit EmulationCE - Customer EdgeCE - Customer EquipmentCE - Cyclic ExtensionCEC - Collaborative Engagement CapabilityCEN - Carrier Ethernet NetworkCEM - Customer Experience Management (formerly DV/SEA)CENTCOM - United States Central CommandCEPCA - Consumer Electronics Communications Alliance

CER - Customer Edge RouterCERN - Conseil Européen pour la Recherche Nucléaire" (CERN)- European Organization for Nuclear ResearchCERS - Contractor Equipment Relocation SystemCERT - Computer Emergency Response TeamCES - Circuit Emulated Services CESoETH - Circuit Emulated Services over ETHernet CEU channel encryption unitCEV - Crew Exploration VehicleCF - Contention-FreeCF - Coupling FlagCFES - Compact Flash EvaporatorCFI - Canonical Format IndicatorCFI - Channel Format IndicatorCFI - Control Format IndicatorCFM - Connectivity Fault ManagementCFO - Carrier Frequency OffsetCG - Center of GravityCGI - Cell Global IdentificationCHAP - Challenge Handshake Authentication ProtocolCHLI - Consecutive High Loss IntervalCI - Characteristic InformationCI - Collection IntervalCI - Contaminant InsensitiveCI - Customer InstallationCIC - Circuit Identification CodeCICS - Customer Information Control SystemCID - Cell IDentifierCID - Context IDentifierCID - Craft Interface DeviceCIDR - Classless Inter-Domain Routing CIEF - Carrier Independent Exchange FacilityCIFA - Counterintelligence Field ActivityCIMS - Cyber Identity Management System (DCNSS)CINR - Carrier-to-Interference-and-Noise RatioCIO - Chief Information OfficerCIO - Corporate Information OfficerCIR - Channel Impulse ResponseCIR - Committed Information RateCITS - Combat Information Transport SystemCJCS - Chairman of the Joint Chiefs of StaffCJCSI - Chairman of the Joint Chiefs of Staff InstructionCKSN - Ciphering Key Sequence NumberCLAN - Converged Local Area NetworkCLE - Customer Located EquipmentCLI - Command Line InterfaceCLIPS - Clientless IP Service SelectionCLV - Crew Launch VehicleCM (Color Mode) - CM is a Bandwidth Profile parameter -either "color blind" or "color aware"CM - Command ModuleCM - Configuration ManagementCMC - Connection Mobility ControlCMDB - Customer Management DataBase

CMDB - Configuration Management DataBaseCMHH - Constant Modulus HouseholderCMOS - Complementary Metal Oxide Silicon CMS - Calix {Compass?} Management SystemCMTS - Cable Modem Termination SystemCN - Core NetworkCN - Core NetworkCNA - Computer Network AttackCND - Computer Network DefenseCNE - Center Network EnvironmentCNES - Centre National d'Etudes SpatialesCNPS - Common Network Planning System CO - Central OfficeCoA - Care Of AddressCOA - Course of ActionCOB - Close of BusinessCOCOM - Combatant Command (Command Authority)CODEC - Coder DecoderCOE - Common Operating EnvironmentCOFDM - Coded Orthogonal Frequency Division MultiplexingCOI - Community of InterestCOLA - Center for Ocean-Land-Atmosphere StudiesCOM - Continuous Operations MessagingCOMINT - Communications intelligence (Communications and Intelligence)COMPUSEC - computer securityCOMSEC - Communications SecurityCONEX - CONtingency Employment eXercise CONEXPLAN - contingency and exercise planCONOPS - Concept of OperationsCONPLAN - operation plan in concept formatCONUS - Continental United States COOP - Continuity of OperationsCOP - Common Operating PictureCOP - Common Operational Picture COPS - Common Open Policy ServiceCORBA - Common Objective Request Broker Architecture CoS - Class of ServiceCoS ID - Class of Service IdentifierCOTR - Contracting Officer's Technical RepresentativeCOTS - Commercial Off The ShelfCP - Cyclic PrefixCPE customer premises equipmentCPI - Computational Physics IncorporatedCPICH - Common PIlot CHannelCPM - Capability Portfolio Manager CPO - CoS Performance ObjectiveCPT - Control Protocol Data Unit TypeCPU - Central Processing UnitCQI - Channel Quality IndicatorCQI - Channel Quality IndicatorCR - Change RequestCR - Clock RecoveryCRAN - Converged Regional Area NetworkCRC - Cyclic Redundancy Check

CRC-2 - reference ECANS projectCRL - Certificate Revocation ListCRM - Customer Relationship ManagerCRTS - Compressed Real time Transport protocolCS - Circuit SwitchedCS - Computing Services (DISA) CS-ACELP - Conjugate-Structure Algebraic-Code-Excited Linear-PredictionCS-CN - Circuit Switched Core NetworkCSA - Canadian Space AgencyCSCF - Call Session Control FunctionCSCI - Computer Software Configuration ItemCSFB - Circuit Switched FallBackCSG - Carrier Strike GroupCSG - Closed Subscriber GroupCSI - Channel State InformationCSI - Cryptographic Support InfrastructureCSIT - Channel State Information at the TransmitterCSMA - Carrier Sense Multiple Access aka CSMA-CD (Collision Detect)CSN - Connected Sub-NetworkCSPF - Constraint based Shortest Path FirstCSR - Customer Service RepresentativeCST - Component SubtypeCSU - Channel Service UnitCTAM - Cable & Telecommunications Association for MarketingCTF - Channel Transfer FunctionCTF - coalition task forceCTO - Chief Technology OfficeCTO - Chief Technology OfficerCTPM - Common Tactical Picture ManagerCUI - Controlled Unclassified InformationCV - Coding ViolationsCVAS - ConVerged Application ServerCVI - CITS Virtualization InfrastructureCVPN - Corporate Virtual Private NetworkCW - Continuous-WaveCWDM - Coarse Wavelength Division Multiplexing CWM - Cisco WAN Manager Cx - ConstellationCxCB - Constellation Control BoardCxP - Constellation ProgramDAA - Designated Approval AuthoritiesDAA - Designated Approval AuthorityDAA - Designated Approving AuthorityDAC - Design Analysis CycleDAC - Digital to Analogue ConverterDACS - Directory Access Control SystemDAI - Downlink Assignment IndexDAM - diagnostic acceptability measureDAMA - Demand Assigned Multiple AccessDARPA - Defense Advanced Research Projects AgencyDAS - Demand Access SystemDAU - Data Acquisition UnitDAU - Defense Acquisition AgencyDAV - Descent Ascent Vehicle (ECANS)

DAV - Desktop Appliance Video (ViTS)DB - DatabasedB - decibeldBm - decibel (refers to 1 Milliwatt)DC - District of ColumbiaDCAA - Defense Contract Audit AgencyDCC - Data Communications ChannelDCCC - Defense Cyber Crime CenterDCCH - Dedicated Control ChannelDCE - Data Circuit terminating EquipmentDCF - DISN Customer ForumDCF - Dispersion Compensated Fiber DCI - Downlink Control InformationDCMA - Defense Contract Management AgencyDCN - Data Communications Network DCNSS - Data Center Network and Security ServicesDCP - Docking Control PanelDCS - Digital Cross-Connect SystemDCSS - Digital Communications Satellite Subsystems DDMS - DoD Discovery Metadata StandardDDOE - DISN Direct Order Entry DECA - Defense Commissary AgencyDECC - Defense Enterprise Computing Center DEI - Discard Eligibility IndicatorDES - Data Encryption StandardDFAS - Defense Finance Accounting AgencyDFB - Distributed FeedBack Laser DFRC - Dryden Flight Research CenterDFT - Discrete Fourier TransformDFT-SOFDM - Discrete Fourier Transform- Spread- Orthogonal Frequency Division Multi-plexingDFTS - Defense Fixed Telecommunications ServiceDHCP - Dynamic Host Configuration ProtocolDHRA - Defense Human Resources ActivityDI - Data InstanceDIA - Defense Intelligence AgencyDIACAP - Department of Defense Information Assurance Certification and Accreditation ProcessDICE - Department of Defense Interoperability Communications ExerciseDID - Direct Inward DialingDiD/DoD - Direct In-Dial/Direct Out-DialDiffServ - Differentiated ServicesDII - Defense Information InfrastructureDIMS - DSCS Integrated Management System DIRNSA - Director, National Security AgencyDISA - Defense Information Systems AgencyDISAC - Defense Information Systems Agency CircularDISN - Defense Information System NetworkDISN - Defense Information Systems NetworkDISO-UNRRA - United National Relief and Rehabilitation AdministrationDISR - Dod Information technology Standards RegistryDITCO - Defense Information Technology Contracting OfficeDITSCAP - DoD Information Technology Security Certification and Accreditation Process

DL - DownLinkDL - TFT Downlink TFTDL-SCH - DownLink Shared CHannelDLA - Defense Logistics AgencyDLC - Data Link ControlDLC - Digital Loop CarrierDLC - Domestic Leased CircuitDLCI - Data Link Connection Identifier (A number attached to a data frame that identifies the PVC for the data frame)DLSA - Defense Legal Services AgencyDLT/DAT - Tape FormatsDM - RS DeModulation Reference SignalDMDC - Defense Manpower Data CenterDMEA - Defense Microelectronics ActivityDMS - Defense Message SystemDMS - Defense Messaging ServiceDMZ - Demilitarized ZoneDN - Directory NumberDNCCB - DISA NetOps Configuration Control BoardDNPS - Defense Satellite Communications System Network Planning Software DNS - Domain Name ServiceDNS - Domain Name SystemDOCSIS - Data Over Cable Service Interface SpecificationDOD - Department Of DefenseDoD - Department of DefenseDOD - Direct - Outward - DialingDOD-IG - Department of Defense - Inspector GeneralDODAF - DOD Architecture FrameworkDODEA - DOD Education ActivityDODMVA - DOD Military Vaccine AgencyDODTRMC - DOD Test Resource Management CenterDOF - Degree of FreedomDP - Discard PriorityDP - Dynamic PricingDPA - Dual Phone AdapterDPC - Destination Point CodeDPM - digital phone multiplexersDPMO - Defense Prisoner of War/Missing Personnel OfficeDPS - Descent Propulsion SystemDQPSK - Differential Quadrature Phase-shift Keying DR - Discrepancy ReportDRA - Dynamic Resource AllocationDRB - Data Radio BearerDREN - Defense Research and Education NetworkDRM - Design Reference MissionsDRM - Digital Rights Management - content protection [IPTV] see CASDRSN - Defense Red Switch NetworkDRT - diagnostic rhyme testDRX - Discontinuous ReceptionDserver - Distribution ServerDS - Data SetDS - Descent StageDS - Direct SpreadDS-CDMA - Direct Sequence- Code Division Multiple Access

DS0 - Digital Signal Level 0 DS1 - Digital Signal Level 1DS3 - Digital Signal Level 3DSAC - Domain Specific Access ControlDSAWG - Security Accreditation Working GroupDSCA - Defense Security Cooperation AgencyDSCP - Differentiated Service Code PointDSCP - Differentiated Services Code PointDSCS - Defense Satellite Communications System DSF - Data Service Frame (A Service Frame that is Unicast, Multicast, or Broadcast)DSL - Digital Subscriber Line DSMC - Data Services Management CenterDSN - Deep Space NetworkDSN - Defense Switched NetworkDSn - Digital Signal at level 'n'DSP - Descent Stage PropulsionDSP - Digital Signal ProcessorDSS - Defense Security ServiceDSS - Destination Surface SegmentDSTM - Derived System Timing ModeDSU - Data Services UnitDT - Developmental TestingDTA - Dual Trunk AdaptorDTAU - Digital Test Access Unit DTC - Digital Telecommunications ConferencingDTCH - Dedicated Traffic CHannelDTD - Document Type DefinitionDTG - Date/Time GroupDTIC - Defense Technical Information CenterDTM - Derived Timing ModeDTMF - Dual Tone Multi - FrequencyDTRA - Defense Threat Reduction AgencyDTSA - Defense Technology Security AdministrationDTX - Discontinuous TransmissionDUT - Device Under TestDVA - Desktop ViTS ApplianceDVB - Digital Video Broadcast DVB-S - Digital Video Broadcast Satellite DVD - Digital Video DiskDVD - Digital Video Diskette, Digital Versatile Disk DVR - Digital Video RecorderDVS - Defense Video ServicesDVX - Deployable Voice ExchangeDVX - Deployable Voice SwitchDWCF - Defense Working Capital FundDWDM - Dense Wavelength Division Multiplexing E&M - Ear and Mouth SignalingE-LAN - Ethernet LAN - An MEF Ethernet LAN (E-LAN) Service Type is any Ethernet service that is based on a Multipoint-to-Multipoint EVCE-Line - Ethernet line service E-LMI - Ethernet Layer Management InterfaceE-Mail - Electronic MailE-NNI - ethernet External Network to Network Interface

E-TREE - Ethernet Tree - An MEF Ethernet LAN (E-Tree) Service Type is any Ethernet service that is based on a Rooted-Multipoint-to-Multipoint EVCE-UTRA - Evolved UMTS Terrestrial Radio AccessE-UTRAN - Evolved UMTS Terrestrial Radio Access NetworkE-UTRAN - Evolved UTRANE-WAN - Ethernet WAN (An MEF defined ETH services aware network that provides connectivity between two or more MENs via ENNIs)E2E - End-to-EndEA - electronic attack EA - Enterprise ArchitectureEA-ILM - Electro-Absorptive Integrated Laser Modulator EAF - ETH (Ethernet) Adaptation FunctionEAM - Electro-Absorptive Modulator EARFCN - E-UTRA Absolute Radio Frequency Channel NumberEBC - Edge Boundary ControllerEBEM - Enhanced Bandwidth Efficient Modem EBNET - EOSDIS Backbone NetworkEBS - Excess Burst SizeEC - Echo CancellerEC - ETH (Ethernet) ConnectionECANS - Exploration Communication & Navigation SystemsECDX - Emulated Circuit De/Multiplexing FunctionECF - Ethernet Connection FunctionECGI - E-UTRAN Cell Global IdentifierECI - E-UTRAN Cell IdentifierECID - Emulated Circuit IdentifierECLSS - Environmental Control and Life Support SystemECM - EPS Connection ManagementECM - Evolved Packet System Connection ManagementECM-EPS - Connection Management ECN - Ethernet Controller Node (Ericsson)ECOC - European Conference on Optical Communication ECS - Environment Control ServiceECT - Ethernet Connectionless TrailEDA - Ethernet Distribution AreaEDC - Electronic Dispersion Compensation EDC - EROS Data CenterEDI - Ethernet Dedicated InternetEDIA - Ethernet Dedicated Internet AccessEDS - Earth Departure StageEEA - Evolved Packet System Encryption AlgorithmEEC - Ethernet Equipment ClockEELV - reference ECANS projectEEPP - End to End Path ProtectionEESM - Exponential Effective Signal to Interference plus Noise Ratio MappingEETF - Ethernet EVC Terminating FunctionEF - Expedited ForwardingEFCF - Ethernet flow Conditioning FunctionEFD - Ethernet Flow DomainEFM - Ethernet in the First Mile EFN - Ethernet Fiber Node (e.g. Ericsson EFN324)EFP - Ethernet Flow PointEFT - Ethernet Flow Termination

EFTF - Ethernet Flow Termination FunctionEHF - extremely high frequency EHPLMN - Equivalent Home Public Land Mobile NetworkEI - End InstrumentEIA - Electronics Industry AssociationEIA - Evolved Packet System Integrity AlgorithmEIR - Equipment Identity RegisterEIR - Excess Information RateEKMS - Electronic Key Management SystemELI - Electric Lightwave NetworkEM - Enterprise ManagementEM - Equipment Manufacturer EMA - Electromechanical ActuatorEMAN - Ecological Monitoring and Assessment Network (Canadian)EMC - ElectroMagnetic CompatibilityEMC - Emergency Management CenterEMERALDS - Enterprise Management with Enhanced Resource Allocation Database System EMI - ElectroMagnetic Interference EMM - EPS Mobility ManagementEMM - Evolved Packet System Connection ManagementEMN - Ethernet Metro NodeEMS - Electronic Maintenance SectionEMS - Element Management SystemEMSS - Enhanced Mobile Satellite ServiceeNB - E-UTRAN Node BENIQ - Ericsson Network Intelligent QuotientENMC - Enterprise Network Management CenterENNI - External (ethernet) Network to Network InterfaceeNodeB - Evolved NodeBENPL - Earth Observatory System (EOS) LaboratoryENS - Ethernet Network ServiceEO - End OfficeEOC - Embedded Operations ChannelEOD - Ethernet Over DOCSISEoDWDM - Ethernet over DWDM EOI - Earth Orbit InjectionEOL - End of LifeEoMPLS - Ethernet over MPLS EOR - Earth Orbit RendezvousEOS - Earth Observation SystemEOS - Ethernet Over SONET EP - Elementary ProcedureEP-LAN - Ethernet Private LAN (Service)EP-TREE - Ethernet Private Tree (Service)EPA - Extended Pedestrian AEPC - Enhanced Pentagon CapabilityEPC - Evolved Packet CoreEPG - Electronics Product Group EPGN - Earth Polar Ground NetworkEPL - Ethernet Private Line (Service)EPOCC - Enhanced Photo Optic Control CenterEPON - Ethernet Passive Optical Network EPP - Enhanced Planning Process

EPRE - Energy Per Resource ElementEPS - Electrical Power SystemEPS - Evolved Packet SystemER - Extended Reach ERBS - Earth Radiation Budget SatelliteEROS - Earth Radiation Observatory SatelliteES - Errored SecondsESA - European Space AgencyESAS - Exploration Systems Architecture StudyESB - enterprise service bus ESC - Ethernet Service ConstructESCON - Enterprise Systems Connectivity ESD - Electrostatic dischargeESD - Ethernet Services DefinitionESF - Extended Super FrameESM - Ethernet Services ModelESM - Evolved Packet System Session ManagementESMD - reference ECANS projectESN - Ethernet SubNetworkESNC - Ethernet SubNetwork ConnectionESNET - Energy Sciences NetworkESOC - ESA Space Operations CenterESP - Encapsulating Security PayloadESP - Essential Service ProtectionESR - Errored Second RatioESTEC - ESA Science and Technology CenterESTL - Electronic System Test LaboratoryESU - Enterprise Services UnitET - External TankETDP - Exploration Technology Development ProgramETH - EthernetETL - Extract / Transform / Load (SD/EEM)eTOM - Enhanced Telecommunications Operations Map ETSI - European Telecommunications Standards InstituteETTV - External Tank TelevisionETU - Extended Typical UrbanETWS - Earthquake and Tsunami Warning SystemEUCOM - United States European CommandEUNI - External Network InterfaceEUT - Equipment Under TestEUTRAN - Evolved UMTS Terrestrial Radio Access Network EUTRAN - Evolved UTRANEV-DO - Evolution for Data OptimizedEVA - Extended Vehicular AEVA - Extravehicular ActivityEVC - Ethernet virtual circuit EVCS - Enterprise Voice Consolidation SystemEVDO - Evolution Data Optimized EVM - Error Vector MagnitudeEVP-LAN - Ethernet Virtual Private Lan (Service)EVP-TREE - Ethernet Virtual Private Tree (Service)EVPL - Ethernet Virtual Private Line (Service)EW-SE - enterprise-wide systems engineering ExTF - reference ECANS project

F - FLASHFA - Foreign AgentFAA - Federal Aviation AdministrationFAMA - Fixed Assignment Multiple Access FastE - Fast EthernetFAX - facsimileFBG - Fiber Bragg Grating FC - Fibre Channel FCAPS - Fault, Configuration, Accounting, Performance, and Security FCC - Federal Communications CommissionFCC - Flight Critical Computers (ECANS)FCS - Frame Check SequenceFCS - Future Combat SystemFD - Frame DelayFDD - Frequency Division DuplexFDDI - Fiber Distributed Data Interface FDE - Frequency-Domain EqualizerFDF - Flight Dynamics FacilityFDIR - Fault Detection, Isolation and RecoveryFDL - Facility Data LinkFDM - Frequency Division MultiplexingFDMA - Frequency Division Multiple AccessFDR - Frame Delay RangeFDSS - Frequency Domain Spectral ShapingFDV - Frame Delay Variation (often misquoted as jitter)FDW - Financial Data WorksheetFDX - Full DupleXFE - Far EndFE - Functional ElementFEA - Federal Enterprise Architecture (FEA)FEC - Forward Error CorrectionFEMTOCELLS - small cellular base stationFER - Frame Error Ratio FEXT - Far-end Crosstalk FFR - Fast (Flow?) RerouteFFRDC - Federally Funded Research & Development CenterFFS - For Further StudyFFSC - Full-flow Staged CombustionFFT - Fast Fourier TransformFFT - Fast Fourier TransformFI - Framing InfoFIPS - Federal Information Processing StandardFIR - Finite Impulse ResponseFISMA - Federal Information Security Management ActFISU - Fill - In Signaling UnitFIX - Federal Internet ExchangeFLR - Frame Loss RatioFM - Fault ManagementFMC - Fixed Mobile ConvergenceFMS - First Missing Service Data UnitFMS foreign military salesFN - First NameFO - FLASH OVERRIDEFOC - Final Operational Capability

FOO - Flash Override OverrideFP - Fabry-Perot FPDS - Fire Protection, Detection, and SuppressionFPI - First Production InstanceFPP - Flow Point PoolFPR - Flight Propellant ReserveFTTC - Fiber To The CellFTTC - Fiber To The CurbFTTCS - Fiber To The Cell SiteFTTH - Fiber To The HomeFQDN - Fully Qualified Domain NameFQP - Firm Quote PriceFRC - Fixed Reference ChannelFS - First StageFS - Frame StructureFSAL - Fixed Security Access LevelFSO - Field Security OfficeFSTD - Frequency Switched Transmit DiversityFT - Fault ToleranceFTP - File Transfer ProtocolFTP - File Transport ProtocolFTS - Federal Telecommunications ServicesFTS - Federal Telecommunications SystemFTTX - Fiber To The (Home, Desk, Building) FUSE - Far Ultraviolet Spectroscopic ExplorerFW - FirewallFY - Fiscal Year GAA - gateway access authorization GaAs - Gallium Arsenide GAR - Gateway Access RequestGARP - Generic Attribute Registration ProtocolGbE - Gigabit EthernetGbps - Giga bits per secondGBR - Guaranteed Bit RateGBS - Global Broadcast ServiceGBS - Global Broadcast System GCCS - Global Command and Control SystemGCL - Generalized Chirp-Like sequencesGCMP - GIG Convergence Master Plan GCSS - Global Combat Support SystemGCTC - Gagarin Cosmonaut Training CenterGDS - Deep Space Network Goldstone Tracking FacilityGDSCC - Goldstone Deep Space Control CenterGEI - reference ECANS projectGERAN - GSM/EDGE Radio Access NetworkGETS Government Emergency Telecommunications ServiceGFE - Government Furnished EquipmentGGND - GIG Network DefenseGGSG - Geodynamics Geophysics and Space GeodessyGGSN - Gateway GPRS Support NodeGHz - Gigahertz GI - Guard IntervalGI-POF - Graded Index Plastic Optical Fiber GIG - Global Information Grid

GIG-BE - Global Information Grid Bandwidth Expansion GigE - Gigabit EthernetGIWF - Generic InterWorking FunctionGLOW - Gross Liftoff WeightGMC - GCCS Management CenterGN - Ground NetworkGN&C - Guidance, Navigation and ControlGNC - Global NetOps Center GNOSC - Global NetOps and Security CenterGNSC - Global NetOps Support CenterGNSS - Global Navigation Satellite SystemGO - GIG OperationsGO - Ground OperationsGOES - Geosynchronous Operational Environmental SatelliteGOS - Grade of ServiceGOTS - Government Off The ShelfGOX - Gaseous OxygenGP - Guard PeriodGPB - Gravity Probe BGPON - Gigabit Passive Optical Network GPRS - General Packet Radio ServiceGPS - General Purpose SegmentGPS - Global Positioning SystemGRC - Glenn Research CenterGRC-TL - Glenn Research Center Technology Laboratory GRE - Generic Routing EncapsulationGRGT - Guam Remote Ground TerminalGSA - General Services AdministrationGSCR - Generic Switching Center RequirementsGSE - Ground Support EquipmentGSFC - Goddard Space Flight CenterGSM - Global System for Mobile CommunicationGSM - Global System for Mobile CommunicationsGSM/EDGE - Radio Access Network (GERAN) or UTRAN CS infrastructure UTRAN coverage is overlapped by GERAN or UTRAN coverageGSN - GPRS Support NodeGSR - Generic System RequirementsGSS - Generic System SpecificationGSSC - Global SATCOM Support Center GST - GIG Standard Ticketing GSU - Geographically Separated UnitGT - Guard TimeGTP - GPRS Tunneling ProtocolGTP-C - GTP-Control planeGTP-U - GPRS Tunneling Protocol-User planeGTP-U - GTP User planeGUID - Globally Unique IDentifier (RFC 4112)GUMMEI - Globally Unique MME Identity GUMMEI - Globally Unique Mobility Management Entity IdentifierGUTI - Globally Unique Temporary IdentityGUTI - Globally unique Temporary UE identityGW - GateWayGWAC - Government-Wide Acquisition Contract H-ARQ - Hybrid ARQ

H-FDD - Half-Frequency Division DuplexH-PCRF - Home Policy and Charging Rules FunctionHA - Home AgentHAIPE - High Assurance Internet Protocol EncryptorHAIPE - High Assurance IP EncryptorHanger AE - Building designationHARQ - ACK/NACK HARQ ACKnowledgement/Negative ACKnowledgement informationHARQ - Hybrid ARQHBA - Host Bus Adapter HD-FDD - Half-Duplex Frequency Division DuplexHDTV - Hi Definition TVHDX - Half DupleXHE - HeadEndHE - Home EnvironmentHEMI - Headquarters Enterprise Messaging InitiativeHEMP High-Altitude Electromagnetic PulseHFC - Hybrid Fiber Coax HFN - Hyper Frame NumberHI - HARQ IndicatorHII - High Interference IndicatorHLI - High Loss IntervalHLN - High Leverage Network HLR - Home Location RegisterHMW health, morale, and welfareHNBID - Home eNodeB IDentifierHO - HandOverHOVC - Higher Order Virtual ContainerHPC - High Performance Computing HPCMO - High Performance Computing Modernization OfficeHPLMN - Home PLMNHPLMN - Home Public Land Mobile NetworkHPOV - HP OpenviewHPR - High Performance Router HPU - Hydraulic Power UnitHQ - HeadquartersHQ - NASA HeadquartersHRPD - High Rate Packet DataHRSI - High-Temperature Reusable Surface InsulationHSBI - High Speed Backplane Initiative HSDPA - High Speed Downlink Packet Access HSF - Human Space FlightHSIR - reference ECANS projectHSPA - High-Speed Packet AccessHSPA+ - High-Speed Packet Access EvolutionHSS - Home Subscriber ServerHST - Hubble Space TelescopeHSUPA - High Speed Uplink Packet AccessHTML - Hypertext Markup LanguageHTR - Hard To ReachHTTP - Hyper Text Transfer Protocolhttpcodes - Informational 1xxhttpcodes - 100 Continuehttpcodes - 101 Switching Protocolshttpcodes - Successful 2xx

httpcodes - 200 OKhttpcodes - 201 Createdhttpcodes - 202 Acceptedhttpcodes - 203 Non-Authoritative Informationhttpcodes - 204 No Contenthttpcodes - 205 Reset Contenthttpcodes - 206 Partial Contenthttpcodes - Redirection 3xxhttpcodes - 301 Moved Permanentlyhttpcodes - 305 Use Proxyhttpcodes - 307 Temporary Redirecthttpcodes - Client Error 4xxhttpcodes - 400 Bad Requesthttpcodes - 401 Unauthorizedhttpcodes - 402 Payment Requiredhttpcodes - 403 Forbiddenhttpcodes - 404 Not Foundhttpcodes - 405 Method Not Allowedhttpcodes - 406 Not Acceptablehttpcodes - 407 Proxy Authentication Requiredhttpcodes - 408 Request Timeouthttpcodes - 409 Conflicthttpcodes - 410 Gonehttpcodes - 411 Length Requiredhttpcodes - 412 Precondition Failedhttpcodes - 413 Request Entity Too Largehttpcodes - 414 Request-URI Too Longhttpcodes - 415 Unsupported Media Typehttpcodes - 416 Requested Range Not Satisfiablehttpcodes - 417 Expectation Failedhttpcodes - Server Error 5xxhttpcodes - 500 Internal Server Errorhttpcodes - 501 Not Implementedhttpcodes - 502 Bad Gatewayhttpcodes - 503 Service UnavailableHTTPS - Hyper Text Transfer Protocol SecureHW - HardwareHWCI - HardWare Configuration ItemHz - HertzI - IMMEDIATEI&W - Indications and Warningsi-mode - mobile internet (as opposed to wireless internet) !WAPI-NNI - Internal NNI (Network to Network Interface)I-NOSC - Integrated Network Operations Security Centersi-TRM - The Air Force Infostructure Technology Reference ModelIA - Implementation AgreementIA - Information AssuranceIAA - Information Assurance AccreditationIAAS - Infrastructure As A ServiceIAD - Integrated Access DeviceIAM - Initial Address MessageIANA - Internet Assigned Number AuthorityIAP - Internet Access PointIAS Integrated access Switch/System

IATF - Information Assurance Technical FrameworkIATO - interim authority to operateIATP - Information Assurance Test PlanIATT - Information Assurance Test TeamIAVA - Information Assurance Vulnerability AlertIAW - In Accordance WithIBMP - Institute of Biomedical ProblemsIC - Integrated Circuit IC - Intelligence CommunityICATS Integrated Configuration And Tracking SystemICE - Refers to the monitoring of actual ice on the orbital prior to launch.ICI - Inter-Carrier InterferenceICI - Interexchange Carrier InterconnectionICIC - Inter-Cell Interference CoordinationICMP - Internet Control Message ProtocolICOM - Input-Control-Output-MechanismICPR - Initial Constellation Program ReviewICS - Implementation Conformance StatementICS - In-Channel SelectivityID - IdentificationID - IDentityID/IR - Intrusion Detection/Incident ResponseIDAC - Integrated Design Analysis CycleIDD - Interface Definition DocumentiDEN - integrated Digital Enhanced NetworkIDFT - Inverse Discrete Fourier TransformIDIQ - Indefinite Demand/Indefinite QuantityIDLC - Integrated Digital Loop CarrierIDMS - Information and Data Management SystemIDNNS - Intra-Domain Non-Access Stratum Node SelectorIDNX - Integrated Digital Network ExchangeIDS - Intrusion Detection SystemIDT - Integrated Digital TerminalIE - Information ElementIEA - reference ECANS projectIEEE - Institute of Electrical and Electronics EngineersIEM - Integrated Enterprise ManagementIEMP - Integrated Enterprise Management ProgramIER - In Effect ReportIER - Information Exchange RequirementsIETF - Internet Engineering Task ForceIFDMA - Interleaved Frequency Division Multiple AccessIFDV - Inter Frame Delay VariationIFFT - Inverse Fast Fourier TransformIGMP - Internet Group Management ProtocolIGP - Interior Gateway ProtocolIIEP - Integrated Inventory Express Pack (NE <=> GRANITE)IIJ - Internet Initiative Japan IL - Insertion Loss ILEC - Incumbent Local Exchange Carrier IM - Implementation MarginIM - Information ManagementIM - Instant Meeting

IMA - Inverse Multiplexing over ATM IMD - InterModulation DistortionIMEI - International Mobile Equipment IdentityIMEISVN - International Mobile Equipment Identity Software Version numberIMS - Internet Protocol Multimedia SubsystemIMS - IP Multimedia SubsystemIMSI - International Mobile Subscriber IdentityIMT - International Mobile TelecommunicationIMT - International Mobile TelecommunicationsIN - Intelligent NetworksINFOCON - Information Operations Threat/Alert ConditionsINFOSEC - Information SecurityINMD - In - service Non - intrusive Measurement DeviceINMS - Integrated Network Management System INNI - Internal Network to Network InterfaceInP - Indium Phosphide IO - InteroperabilityIOC - Initial Operational CapabilityIONet - Internet Protocol Operational NetworkIOV-UI - Input Offset Value - Unconfirmed InformationIP - Internet ProtocolIP-CAN - Internet Protocol Connectivity Access NetworkIPAM - Internet Protocol Address ManagementIPD - Integrated Powerhead DemonstratorIPDV - Ip Packet Delay Variation [ITU-T Y.1541]IPER - Ip Packet Error Ratio [ITU-T Y.1541]IPLC - International Private Leased Circuit IPLR - Ip Packet Loss Ratio [ITU-T Y.1541]IPMSAN - IP Multi Service Access NetworkIPMSAN - IP Multi Service Access NodeIPNOC - Internet Protocol Network Operating CenterIPOT - Octet based IP packet Throughput [ITU-T Y.1541]IPPT - IP Packet Through put [ITU-T Y.1541]IPS - Integrated Planning SystemIPSC - IP Stream ConnectIPSec - Internet Protocol SecurityIPSec - IP Security IPTD - Ip Packet Transfer Delay (commonly referred to as latency) [ITU-T Y.1541]IPTV - Internet Protocol TelevisioniPV - internet based manual Procedure ViewerIPv4 - Internet Protocol version 4IPv4 - IP Version 4IPv6 - IP Version 6IQ - In-phase - Quadrature phaseIR - Incremental RedundancyIRC - Infra-red CamerasIRC - Interference Rejection CombiningIRD - Interface Requirements DocumentIRIS - Internet Protocol Router in Space IRV - Incremental Redundancy VersionISA - Industry Standard ArchitectureISAM - Intelligent Services Access ManageriSCSI - IP Small Computer System Interface

ISD - Inter-Site DistanceISDN - Integrated Service Digital NetworkISDNUP - Integrated Services Digital Network User PartISHM - Integrated System Health ManagementISI - Inter-Symbol InterferenceISIS - Intermediate System to Intermediate System protocolISP - Information Support PlansISP - Internet Service Provider ISPAN - Integrated Strategic Planning and Analysis Network ISR - Idle state Signalling ReductionISR - Intelligence, Surveillance, and ReconnaissanceISR - Internet Screening RouterISRU - In-Situ Resource UtilizationISS - International Space StationIST - interswitch trunkISTC - Information Systems Technical ControlISUP - Integrated Services Digital Network User PartISUP - ISDN Signaling User Part ISUP - ISDN User PartIT - Information TechnologyITA-PENTCIRT - Information Technology AgencyITIL - IT Infrastructure LibraryITIL® - Information Technology Infrastructure Library ITMC - International Telecommunications Management CenterITS - Information Transport SystemITSM - Information Technology Security ManagerITT - Integrated Test TeamITU - International Telecommunication UnionITU - International Telecommunications UnionITU-R - International Telecommunication Union Radiocommunication sectorITU-T - Telecommunications Standardization SectorIU - Instrument UnitIUA - ISDN User AdaptationIV&V - Independent Verification and Validation FacilityIVA - Intravehicular ActivityIWF - Interworking FunctionIXC - Inter-exchange Carrier IXIT - Implementation eXtra Information for TestingJASON-1 - The JASON Project is an organization engages students in scientific research and expeditions led by leading scientists. Named after the mythical character Jason of the Argonauts.JAXA - Japan Aerospace Exploration AgencyJBC - Joint Battle CenterJBOD - Just a Bunch Of Disks JBS - Joint Broadcast ServiceJCCC - Joint Communications Control CenterJCS - Joint Chiefs of StaffJCSE - Joint Communications Support ElementJCTD - Joint Capabilities Technology Demonstration JDAWS - JCS Data Access Web Server JDBC - Java DataBase ConnectivityJET - Joint Engineering TeamJFCOM - Joint Forces CommandJHU - John Hopkins University

JIC - Joint Interoperability CertificationJIEO - Joint Information and Engineering OrganizationJIPM - Joint IP modem JISE - Joint Intelligence Support ElementJIST-NET - Joint Integrated System Technology Network JITC - Joint Interoperability Test CommandJMOS - Joint Management Operations Subsystem JNMS - Joint Network Management System JNO - Joint Net-Centric Operations JOC - Joint Operations CenterJOIN - Joint On-demand Interoperability NetworkJOPES - Joint Operations Planning and Execution SystemJPL - Jet Proportion LaboratoryJS - Joint StaffJSC - Johnson Space CenterJSC - Joint Spectrum Center JSCP - Joint SATCOM Communications Plan JSMPS - Joint SATCOM Management and Planning System JSOTF - Joint Special Operations Task ForceJTA - Joint Technical ArchitectureJTDLMP Joint Tactical Data Link Management PlanJTF - Joint Task Force JTF-GNO - Joint Task Force - Global Network Operations JUICE - Joint User's Interoperability Communications ExerciseJV2010 - Joint Vision 2010JWCA - Joint Warfighter Capability AssessmentJWICS - Joint Worldwide Intelligence Communications SystemKAFB - Kirtland Air Force BaseKb - KilobitsKbps - Kilo bits per secondKg - KilogramKHSC - Khrunichev Space CenterKHz - Kilo HertzKHz - KiloHertzKIV (not an acronym) K (cryptographic) the I (data comm) V (removable)km - kilometer KMI - Key Management InfrastructureKMIEN - KMI Enclave NodekN - KiloNewtonKP - Key ProcessorKPP - Key Performance ParametersKPI - Key Performance IndicatorKQI - Key Quality IndicatorKSC - Kennedy Space CenterKSI - Key Set IdentifierKSOE - Key Systems Operation ExchangeL/D - Lift to Drag RatioL1 - Layer 1 (physical layer)L2 - Layer 2L2+ - Layer(s) above L2L2CP - Layer 2 Control ProtocolsL2TP - Layer 2 Tunneling ProtocolL2VPN - Layer 2 VPNL3 - Layer 3

L3 - Layer 3 (network layer)LA - Location AreaLAC - Location Area CodeLACP - Link Aggregation Control ProtocolLAG - Link Aggregation GroupLAI - Location Area IdentityLAN - Local Area NetworkLANE - ATM LAN EmulationLANM - LANDSAT, Lanham, MDLaRC - Langley Research CenterLAS - Launch Abort SystemLASD - Local Assured Service DomainLASP - Laboratory for Atmospheric and Space PhysicsLAT - Launch Abort TowerLATA - Local Access and Transport AreaLAV - Launch Abort VehicleLB - Load BalancingLB - Loop BackLbf - Pound ForceLBI - Linked Evolved Packet System Bearer IDLBM - LoopBack MessageLBR - LoopBack ReplyLBRM - Limited-Buffer Rate MatchingLC-39 - Launch Complex-39LCAS - Link Capacity Adjustment SchemeLCC - Local Control CenterLCG - Logical Channel GroupLCID - Logical Channel IDLCK - LoCKed - used in reference to LCK PDULCMT - Lockheed Martin facilityLCR - Low Chip RateLD - Long DistanceLDAP - Lightweight Directory Access ProtocolLDBP - Logistics Data BankLDIF - LDAP Interchange FormatLDPC - Low-Density Parity CheckLDS - Local Digital SwitchLEO - Low Earth OrbitLES - Launch Escape SystemLH2 - Liquid HydrogenLI - Lawful InterceptLI - Length IndicatorLi-Ion - Lithium-IonLIDAR - Light Detection and RangingLIDS - Low Impact Docking SystemLIPPS - LANDSAT IP Processing SystemLISN - Line Impedance Stabilizing NetworkLITT - Littleton, ColoradoLLC - Logical Link ControlLLO - Low Lunar OrbitLLR - Log-Likelihood RatioLMD - Local Management DeviceLMMSE - Linear Minimum Mean Squared ErrorLMMSI - Lockheed Martin Missiles and Space Inc.

LMS - Least Mean SquareLN - Last NameLNA - Low Noise AmplifierLO - Local OscillatorLOA - Linear Optical Amplifier LOE - Level Of EffortLOF - Loss Of FrameLOFS - Loss Of Frames StateLOH - Line OverHeadLOI - Lunar Orbit InsertionLOMF - Laser Optimized Multimode Fiber LOPS - Loss Of Packet SynchronizationLOR - Lunar Orbit RendezvousLOS - Line-Of-SightLOS - Loss Of SignalLOSS - Loss Of Signal SecondsLOVC - Lower Order Virtual ContainerLOX - Liquid OxygenLPC - linear predictive codingLPM - Link Protection MechanismLPRP - Lunar Precursor Robotics ProgramLPS - Launch Processor SystemLR - Location RegistrationLR - Long Reach LRA - Local Registration AuthorityLRC - Langley Research CenterLROC - Long Range Optical CameraLS - Least SquaresLS - Liaison StatementLSAM - Lunar Surface Access ModuleLSAT - Land Remote Sensing SatelliteLSB - Least Significant BitLSC - Local Session ControllerLSF - Last Segment FlagLSP - Lable Switched PathLSR - Lable Switched RouterLSSGR - LATA Switching System Generic RequirementsLSSU - Link Status Signaling UnitLTE - Line Termination EquipmentLTE - Long Term EvolutionLTM - LinkTrace MessageLU - Line UnitLUT - Launch Umbilical TowerLW - Long Wavelength LZP - Level Zero ProcessingM - Megam - milliM-TMSI - M Temporary Mobile Subscriber IdentityM1 - User plane interface between Multimedia Broadcast and Multicast Service GateWay (MBMS GW) and eNodeBM2 - Control plane interface between Multicell/Multicast Coordination Entity (MCE) and eNodeBM2PA - MTP2 User Peer - to - Peer AdaptationM2UA - MTP2 User Adaptation

M3 - Control plane interface between Evolved Packet Core (EPC) and E-UTRAN (Multimedia Broadcast and Multicast Service GateWay (MBMS GW) - Multi-Cell/Multicast Coordination Entity (MCE))M3UA - MTP3 User Adaptation MA - Maintenance AssociationMAC - Media Access ControlMAC - Medium Access ControlMAC - Message Authentication CodeMAC - Move-Add-ChangeMAC-I - Message Authentication Code for IntegrityMAE - Metropolitan Access ExchangeMAE - Metropolitan Area ExchangeMAF - Michoud Assembly FacilityMAID - Maintenance Association (equivalent to MEG)MAJCOM - Major CommandMAN - Metropolitan Area NetworkMAP - Maximum A-posteriori ProbabilityMAS - MMC Automated SystemsMAX - Mid Atlantic CrossroadsMB - MegaByteMBB - Mobile BroadBandMBGP - Multi-protocol Border Gateway ProtocolMBH - Mobile BackHaulMBMS - Multimedia Broadcast Multicast Service Mbps - Mega bits per secondMBR - Maximum Bit RateMBSFN - MBMS Single Frequency NetworkMBSFN - Multimedia Broadcast Single Frequency NetworkMCA - maximum calling areaMCC - Mission Control CenterMCC - Mobile Country CodeMCC-H - Mission Control Center - HoustonMCC-M - Mission Control Center - MoscowMCC1 - reference ECANS projectMCCH - Multicast Control CHannelMCCS - Mission Control Center SystemMCDTV - Multi Channel Digital TelevisionMCE - Multi-Cell/Multicast Coordination EntityMCF - MAC Convergence FunctionMCH - Multicast CHannelMCIP - Mission Critical Internet ProtocolMCM - Multi-Carrier ModulationMCPTi - Milstar Communications Planning Tool - integrated MCS - Modulation and Coding SchemeMCU - Multiport Control UnitMD - Maintenance Domain (equivalent to OAM Domain)MD - Maintenance EntityMD level - Maintenance Domain Level (equivalent to a MEG level)MDA - Missile Defense AgencyMDA - Multifunction Digital AdaptorMDDS - Multi-Domain Dissemination ServerMDM - Multiplexer/DemultiplexerMDSCC - Madrid Deep Space Control CenterME - Mobile Equipment

MEF - Metro Ethernet ForumMEG - Maintenance Entity GroupMEGI - Maintenance Entity Group IdentifierMEGL - Maintenance Entity Group LevelMEHS - Multi-environment Evaporative Heat SinkMEL - reference ECANS projectMEMs - Micro-Electro-mechanical machines MEN - Metro Ethernet NetworkMENE - Metro Ethernet Network ElementMEOP - Maximum Expected Operating PressureMEP - Maintenance EndPointMER - Mars Exploration RoversMER - Minimal Essential RequirementsMF - Multi - FrequencyMFD - Mean Frame DelayMF-TDMA - Multiple Frequency - Time Division Multiple Access MFS - Multi-Function SwitchMFSS - Multi-function SoftswitchMG - Media GatewayMGC - Media Gateway ControllerMGCF - Media Gateway Control FunctionMGCP - Media Gateway Control ProtocolMGW - Media GatewayMHz - Mega HertzMI - Measurement IntervalMIB - Management Information BaseMIB - Master Information BlockMICS - Management and Information Control SystemMIDAS - Multiplexer Integration and DCSS Automation System MIDB - Modernized Intelligence Data BaseMIF - MAC Independant FunctionMIL-STD - Military StandardMILA - Merritt Island Launch AnnexMILDEP - Military DepartmentMILSATCOM - military satellite communications MILSTAR - Military Strategic and Tactical Relay SatelliteMIMO - Multiple Input Multiple Output MIMU - Miniature Inertial Measurement UnitMIP - Maintenance Intermediate PointMIP - MEG Intermediate PointMIP - Mobile Internet ProtocolMIP - Mobile IPMISO - Multiple Input Single OutputMIX - Marshall Image ExchangeML - Maximum LikelihoodML - Mobile LauncherMLD - Maximum Likelihood DetectorMLI - Multi-Layer InsulationMLP - Mobile Launch PlatformMLPP - Multilevel Precedence and PreemptionMLPPP - Multilink Point-to-Point Protocol MLS - multilayer switch MLS - Multilevel SecurityMM - Mobility Management

MMD - Multimedia DomainMME - Mobility Management EntityMMEC - Mobility Management Entity CodeMMEGI- MME Group Identity MMF - Multi-mode Fiber MMH - Monomethyl HydrazineMMP - Margin Management PlanMMS - Multimedia Messaging ServiceMMSE - Minimum Mean Squared ErrorMN - Middle NameMNC - Mobile Network CodeMNE - Multi-National ExperimentMNU - Maximum Number of UNIsMO - Managed ObjectMO - Monitored ObjectMOA - memorandum of agreementMOC - Mission Operations CenterMOCC - Mission Operations Control CenterMOCN - Multi-Operator Core NetworkMOCVD - Metal-Oxide Chemical Vapor Deposition MOCVD - Metallo-Organic Chemical Vapor Deposition MONS - Mission Outage Notification SystemMOP - Maximum Output PowerMOS - Mean Opinion ScoreMOT&E - Multi-service Operational Test and EvaluationMOU - memorandum of understandingMOVE - Mission Operations Voice EnhancementMPBN - Mobile Packet Backhaul NetworkMPE - (AEHF) MPE - Mission Planning Element MPEG - Motion Picture Experts Groupmph - Miles Per Hour MPLS - Multi-Protocol Layer SwitchingMPLS-TP - Multiprotocol Label Switching-Transport Profile MPR - Maximum Power ReductionMPS - Main Propulsion SystemMPSA - Military Postal Service AgencyMPSR - Multi-Purpose Support RoomMPTFO - Mission Planning, Training & Flight OperationsMPV - Manual Procedure ViewerMRC - Maximum Ratio CombiningMRDS - Mission Routed Data ServiceMREN - Metropolitan Research and Education NetworkMRP - Mouth Reference PointMRRU - Maximum Reconstructed Reception UnitMRTIE - Maximum Relative Time Interval Errorms - MillisecondsMS - Mission SystemsMS - Mobile StationMSA - Multi-source Agreement MSAP - Multicast channel Subframe Allocation PatternMSAP - MultiService Access PlatformsMSB - Most Significant BitMSC - Mobile Switching CenterMSD - Maximum Sensitivity Degradation

MSE - Mean Squared ErrorMSFC - Marshall Space Flight CenterMSFI - Marshall Space Flight Center-institutionalMSISDN - Mobile Station International Subscriber Directory NumberMSO - Multiple System Operator MSOC - JSC Mission Support Operations ContractMSP - mobile service provider MSPP - Multi-Service Performance Platform MSRD - Mission Support Routed DataMSRDS - Mission Support Routed Data ServiceMSS - Maximum Segment SizeMSS - Mobile Satellite SystemMSSS - Malin Space Science SystemsMSTP - MultiService Transport PlatformMSU - Message Signaling UnitMS® - Microsoft mT - Metric TonMTCH - MBMS Traffic ChannelMTCH - Multicast Traffic CHannelMTF - Message Text FormatMTNM - Multi-Technology Network Management MTOSI - Multi Technology Operations System(s) InterfaceMTP - Message Transfer PartMTSO - mobile telephone switching office MTTR - Mean Time to RestoreMTU - Maximum Transfer UnitMTU - Maximum Transmission UnitMTV - Mars Transfer VehicleMU-MIMO - Multi-User Multiple-Input Multiple-OutputMUF - Military-Unique featureMUOS2 - Mobile User Objective System MUSE - Multi-service access Everywhere MUX/DEMUX - Multiplexer/Demultiplexer MWC - Mobile World CongressN/S - Not SpecifiedNACC - Network Assisted Cell ChangeNACK - Negative ACKNACK - Negative ACKnowledgmentNACS - Non-Adjacent Channel SelectivityNAF non-appropriated fundNANOG - North American Network Operator GroupNAOC - National Airborne Operations CenterNAPT - Network Address Port TranslationNARNet - Notice of Ammunition Reclassification Network NAS - Network Associated StorageNAS - Non Access StratumNASA - National Aeronautics and Space AdministrationNASIRC - NASA Automated Systems Incident Response CapabilityNAT - Network Address TranslationNATO - North Atlantic Treaty OrganizationNBC - National Business CenterNBM - Network Based Mobility NC - Network ClusterNCA National Command Authorities

NCARS - NISN Cyber Attack Response SystemNCC - Network Colour CodeNCES - Net-Centric Core Enterprise ServicesNCES - Net-Centric Enterprise ServicesNCI - NASA Collaborative InfrastructureNCID - Net-Centric Implementation Documentation NCL - Neighbour Cell ListNCM - Network Cluster Member NCMS - Network Configuration Management SystemNCN - NATO Core Network NCOW - Net-Centric Operations and WarfareNCOW-RM - Network Centric Operations and Warfare - Reference Model NCS - National Communications SystemNCSA - NISN Customer Scheduling AwarenessNDC - NASA Data CenterNDCOS - Network Data Collection Operations SystemsNDI - New Data IndicatorNDN - National Defense NetworkNDS - Network Domain SecurityNDU - National Defense UniversityNE - Near EndNE - Network ElementNEC - Network Equipment CenterNEC - Network Equipment CorpNECC - Net-Enabled Command CapabilityNENA - Naional Emergency Number AssociationNEO - Non-Combatant Evacuation OperationNESC - NASA Engineering and Safety CenterNET/SYSCON - Network System ControlNetCOORD - NetOps CoordinationNetCOP - NetOps Common Operational PictureNETOPS - Network OperationsNF - Noise FigureNFOEC - National Fiber Optics Engineering Conference NGA - National Geospatial-Intelligence AgencyNGIX - Next Generation Internet ExchangeNGMN - Next Generation Mobile NetworksNGO - Non-Government OrganizationNGOSS - Next Generation Operations Systems and Software NGST - Next Generation Space TelescopeNI - Network IdentifierNI - Network InterworkingNI-NNI - Network Interworking NNINIC - Network Indicator CodeNIC - Network Integration CenterNIC - Network Interface Card NII - Network and Information Integration (see OASD/NII) NIIS - NASA Integrated Information SystemNILE - Network Integration Lab EnvironmentNIMA - National Imagery and Mapping AgencyNIPC - National Information Protection InfrastructureNIPRNET - Non-Classified Internet Protocol Router NetworkNIPRNet - Nonsecure Internet Protocol Routed NetworkNIPRNET - Sensitive, but unclassified Internet Protocol

NISC - NASA Information Support CenterNISE - NASA Integrated Services EnvironmentNISN - NASA Integrated Services NetworkNISSU - NASA Infrastructure System Services UtilityNIST - National Institute of Standards and TechnologyNITZ - Network Information and Time ZoneNLMS - Normalized Least-Mean-SquareNLOS - Non-Line-Of-Sightnm - nanometer NM - Network ManagementNMC - Network Management CenterNMCC - National Military Command CenterNMCC - Network Management Configuration ControlNMCS - National Military Command SystemNMS - Network Management System / ServerNNI - Network (to) Network InterfaceNNM - Network Node ManagerNNO - Natioanl Network OperationsNNSF - NAS Node Selection FunctionNOAA - National Oceanic & Atmospheric AdministrationNOC - Network Operations CenterNODE - a provider owned network elementNOMC - NISN Operations Management CenterNORAD - North American Aerospace Defense CommandNORAD North American Aerospace Defense CommandNORTHCOM - United States Northern CommandNOSC - Network Operations and Security CenterNOSL - NISN Operation and System LaboratoryNPD - NASA Policy DirectiveNPN - NISN Prototyping NetworkNREN - NASA Research and Engineering NetworkNRI - Network Resource IdentifierNRL - Naval Research LaboratoryNRO - National Reconnaisance OrganizationNRO - National Reconnaissance OfficeNRS - NASA Collaborative Infrastructure (NCI) Request SystemNS - Network Services (DISA)NS/EP National Security and Emergency PreparednessNSA - National Security Agency NSAP - Network Service Assurance PlanNSAPI - Network layer Service Access Point IdentifierNSAT - NISN Service Announcement ToolNSBF - National Scientific Balloon FacilityNSBFTX - National Scientific Balloon Facility, Palestine, TexasNSE - Network Switching ElementNSF - National Science FoundationNSI - NASA Science InternetNSR - NISN Service RequestNSRS - NISN Service Request SystemNSS - National Security SystemNSS - Network Security ServicesNSSC - NASA Shared Service CenterNSSTC - NASA Space Science and Technology Center

NSTISSD - National Security Telecommunications & Information Systems Security DirectiveNSWSC - Naval Space Warfare Systems Center (now known as SPAWAR)NT - Network TerminationNTAS - NORAD Tactical AUTOVON SystemNTISSI - National Telecommunications & Information Systems Security InstructionNTO - Nitrogen TetroxideNTR - NSAP Technology RefreshNTU - Network Termination UnitNUT - Non-preemptible Unprotected TrafficO&C - Operations & CheckoutO&M - operation and maintenanceO/A - Optimized AccessOA&M - Operations, Administration and Maintenance OADM - Optical Add/Drop Multiplexer OAFB - Onizuka Air Force BaseOAM - Operation and MaintenanceOAM - operations, administration and maintenance OAN - Operational Area NetworkOARNET - Ohio Academic and Research NetworkOASD/NII - Office of the Assistant Secretary of Defense Network and Information Integration OASIS - Organization for the Advancement of Structured Information Standards OBW - Occupied BandWidthOC-x - Optical Carrier OCH - Optical CHannelOCNG - Orthogonal Frequency Division Multiple Access Channel Noise GeneratorOCONUS - outside continental United States (CONUS)OCSP - Online Certificate Status ProtocolOCU - Office Channel UnitOD - Optionally present, DiscontinueODB - Operator Determined BarringODBC - Open Database ConnectivityODF - Optical Distribution FrameODIN - Outsourced Desktop InitiativeODRC - Orbiter Data Reduction ComplexODXC - optical digital cross connect OEA - Office of Economic AdjustmentOEM - Original Equipment Manufacturer OEO - Optical-to-Electrical-to-Optical OFC - Optical Fiber Communications Conference OFCS - Offline Charging SystemOFDM - Orthogonal Frequency Division MultiplexingOFDMA - Orthogonal Frequency Division Multiple AccessOI - Overload IndicatorOIF - Optical Internetworking Forum OJT - On-the-job trainingOLT - Optical Line TerminationOMB - Office of Management and BudgetOMC - Operation and Maintenance CentreOML - Outer Mold Line

OMS - Orbital Maneuvering SystemON - Optionally present, No actionONS - Optical Network SwitchONT - Optical Network TerminalsOOB - Out Of BandOOTW - Operations Other Than WarOP - Optionally PresentOPC - Originating Point CodeOPDIR - Operational DirectionOPERA - Open PLC European Research Alliance OPFAC - Operations FacilityOPLAN - Operations PlanOPORD - Operations OrderOPR - Office of Primary ResponsibilityOPUS - Open Source Unix SoftwareOS - Operating SystemOSA - Optical Sub-assembly OSC - Orbital Sciences CorporationOSD - Office of the Secretary of DefenseOSF - Operational Support FacilityOSI - Open Systems InterconnectionOSM - Operational SATCOM Manager OSPF - Open Shortest Path FirstOSS - Operations Support System OSS - Operations System Support OSS-J - OSS through Java OSTPV - on-station procedure ViewerOT - Operational TestingOTDR - Optical Time Domain Refectometer OTF - Operations Technology FacilityOTS - Optical Transmission Section OTS - Organization Tracking SystemOVC - Operator Virtual ConnectionOVC - Operator Virtual Circuit (Virtual connection between UNI and ENNI end points with "on-net/off-net" indicator)OVC-EP - Operator Virtual Connection Endpoint (OVC association with specific external interface i.e. UNI, ENNIOVCI - Operator Virtual Connection IdentiferP - Polling bitP - PRIORITYP&ID - reference ECANS projectP&P - Practices and ProceduresP&P - Pressurization & PneumaticsP-GW - Packet data Network GateWayP-GW - PDN GatewayP-MCCH - Primary Multicast Control CHannel (MCCH)P-RNTI - Paging Radio Network Temporary IdentityP-SCH - Primary Synchronization ChannelP-TMSI - Packet Temporary Mobile Subscriber Identity (TMSI)P-VLAN - Provider VLANP/S - Parallel-to-SerialP2P - Peer to PeerP2P - point-to-point PA - Power Amplifier

PAAS - Platform As A ServicePACOM - United States Pacific CommandPACOR - Packet ProcessorPAIX - Palo Alto Internet ExchangePALS - Program Automated Library SystemPAO - Public Affairs OfficePAPR - Peak-to-Average Power RatioPAT - Precedence Access ThresholdPATH - a sucession of interconnected links at a specific (ETH or TRANS) layerPB - Pass BandPBAN - reference ECANS projectPBB - Provider Backbone Bridge PBCH - Physical Broadcast CHannelPBD - Program Budget DecisionPBEM - Policy Based Enterprise ManagementPBM - policy based management PBNM - Policy-Based Network ManagementPBR - Prioritized Bit-RatePBX - Private Branch ExchangePBX1 - Private Branch Exchange Type 1PBX2 - Private Branch Exchange Type 2PBX2 - Private Branch Exchange Type 2 (MLPP)PC - Personal Computer PC - Power ControlPCA - Potential Cause AnalysisPCC - Policy Control and ChargingPCCC - Parallel Concatenated Convolutional CodePCCH - Paging Control CHannelPCCW - Hong Kong Telecommunications ResearchPCDATA - Parsed Character DATA [ XML (#PCDATA) ]PCEF - Policy and Charging Enforcement FunctionPCEF - Policy Control Enforcement FunctionPCFICH - Physical Control Format Indicator CHannelPCG - Project Coordination GroupPCH - Paging CHannelPCI - (or PCID) Physical Cell IdentifierPCI - Peripheral Computer Interface PCI - physical cell identityPCM - Pulse Code ModulationPCO - Protocol Configuration OptionsPCP - Power Control PanelPCP - Priority Code PointPCRF - Policy and Charging Rule FunctionPCRF - Policy Control and Charging Rules FunctionPCS - Physical Coding Sub-LayerPCU - Power Control UnitPDA - Personal Data AssistantPDB - Packet Delay BudgetPDC - Program Designator CodePDCCH - Physical Dedicated Control ChannelPDCCH - Physical Downlink Control CHannelPDCP - Packet Data Convergence ProtocolPDF - Probability Distribution Function

PDH - Plesiochronous Digital Hierarchy PDL - Ponce DeLeon - MILA Sub stationPDN - Packet Data NetworkPDN - Public Data Network PDP - Packet Data ProtocolPDP - Performance Data ProviderPDP - Policy Decision PointPDP - Power Delay ProfilePDS - Protected Distribution SystemPDSCH - Physical Downlink Shared CHannelPDSN - Packet Data Serving Node PDU - Product Development UnitPDU - Protocol Data UnitPE - Premise EdgePE - Provider EdgePE - Price EstimatePEM - Proton Exchange MembranePEO-IAN - Program Executive Office for Information Assurance Network OperationsPEP - Policy Enforcement PointPEP - Policy Execution PointPEP - Protocol Enhancing Proxy PER - Premise Edge RouterPF - Packet FlowPF - Paging FramePFCU - Pyro Fire Control UnitPFI - Packet Flow IdentifierPFLT - Poker FlatsPFPA - Pentagon Force Protection AgencyPFS - Proportional Fair SchedulingPGW - PDN gateway PH - Power HeadroomPHB - Per-Hop BehaviorPHICH - Physical Hybrid ARQ Indicator CHannelPHR - Power Headroom ReportPHY - Physical LayerPIC - Photonic Integrated Circuit PICS - Protocol Implementation Conformance StatementPIM - Protocol Independant MulticastPIN - p Intrinsic n detector PIN - personal identification numberPIP - Premium Internet ProtocolPIR - Peak Information RatePIX - Private Internet ExchangePIXIT - Protocol Implementation eXtra Information for TestingPKI - Public Key InfrastructurePL - Path-LossPLC - Photonic Lightwave Circuit PLC - Power Line Communications PLL - Phase-Locked LoopPLMN - Public Land Mobile NetworkPLR - Packet Loss RatePM-DCATS - Project Manager - Defense Communications and Army Transmission Systems

PMA - Pressurized Mating AdapterPMAD - Power Management and DistributionPMBT - Propulsion Mean Bulk TemperaturePMCH - Physical Multicast CHannelPMD - Polarization Mode Dispersion PMI - Precoding Matrix IndicatorPMIP - Proxy MIP PMIP - Proxy Mobile Internet ProtocolPMM - Packet Mobility ManagementPMO - Program Management OfficePN - Pseudo-NoisePN - Pseudo-random NoisePO - Paging OccasionPOF - Plastic Optical Fiber POLAR - Polar Plasma LaboratoryPOM - Program Objective MemorandumPON - Passive Optical Network POP - Point of PresencePOS - Packet over SONET/SDHPOTS - Plain Old Telephone ServicePPF - Paging Proceed FlagPPP - Point-to-Point ProtocolPPPoE - Point-to-Point Protocol over EthernetPRA - Primary Rate AccessPRA - Probabilistic Risk AnalysisPRACH - Physical Random Access CHannelPRB - Physical Resource BlockPRBS - Pseudo Random Binary SequencePRC - Primary Reference Clock PRI - Primary Rate InterfacePS - Packet SwitchedPSA - Principal Staff AssistantsPSAP - Public Safety Answering PointPSD - Power Spectral DensityPSDU - Protocol Service Data UnitPSLA - Program Service Level AgreementPSN - Public Switched NetworkPSS - Primary Synchronization SignalPSS_RA - Primary Synchronization Signal to Reference Signal Energy Per Resource Element RatioPSTN - Public Switched Telephone NetworkPSU - Pennsylvania State UniversityPSU - Power Switching Unit (ECANS)PT - Pressure TransducersPTCS - Passive Thermal Control SystemPTI - Procedure Transaction IDentityPTP - Programmable Telemetry ProcessorPTT - Post, Telegraph, and TelephonePTT - Public Telephone and TelegraphPUCCH - Physical Uplink Control CHannelPUSCH - Physical Uplink Shared CHannelPVC - Permanent Virtual CircuitPVR - Personal Video RecorderPW - Pseudo Wire

PWS - Public Warning SystemQ & A - Question and AnswerQAM - Quadrature Amplitude ModulationQCI - QoS Class identifierQCI - QoS Class Identifiers QCI - Quality of Service (QoS) Class IdentifierQoE _ Quality of ExperienceQoS - Quality of ServiceQPP - Quadratic Permutation PolynomialQPSK - Quadrature Phase Shift KeyingQSTU - Quad SHDSL Termination UnitR - ReservedR - RoutineR-KPI - Resource KPIR-PLMN - Registered Public Land Mobile Networkr.m.s. - root mean squareRA - Random AccessRA - Registration AuthorityRA - Resource AllocationRA - Routing AreaRA-RNTI - Random Access Radio Network Temporary IdentifierRAB - Radio Access BearerRAC - Radio Admission ControlRAC - Routing Area CodeRACH - Random Access CHannelRAD - Reference Architecture DocumentRAI - Remote Alarm IndicationRAI - Routing Area IdentityRAID - Redundant Array of Independent Disks RAN - Radio Access NetworkRAPID - Random Access Preamble IDentifierRAR - Random Access ResponseRAT - Radio Access TechnologyRAU - Routing Area UpdateRB - Radio BearerRB - Resource BlockRBC - Radio Bearer ControlRBG - Radio Bearer GroupRBG - Resource Block GroupRBOC - Regional Bell Operating Company RBS - Radio Base StationRCA - Root Cause AnalysisRCIP - Real-time Critical Internet ProtocolRCN - Regional Communications NetworkRCS - Reaction Control SystemRDI - Remote Defect IndicationRDIR - Routed Data Infrastructure RefreshRDP - Requirements and Design PhaseRDP - Requirements and Design PlanRDT - Remote Digital TerminalRE - Resource ElementREFSENS - REFerence SENSitivity power levelREG - Resource Element Group

RESE - Canadian Réseau d'Evaluation et de Surveillance Ecologiques or Canadian Ecological Monitoring and Assessment Network (EMAN)REST - Representational State TransferRET - Remote Electrical TiltingRF - Radio FrequencyRF - Resegmentation FlagRFC - Request for CommentRFI - radio frequency interference RFI - Request for InformationRFSOC - Radio Frequency Simulations Operations CenterRFSP - Radio Access Technology / Frequency Selection PriorityRFTS - Remote Fiber Test SystemRG - Residential GatewayRG-STB - Residential Gateway Set Top BoxRHESE - Radiation Hardened Electronics for Space EnvironmentsRI - Rank IndicatorRIA - Rich Internet ApplicationsRIM - Radio Access Network Information ManagementRIPE - Reseaux Internet Protocol Europeens (Francais)RIV - Resource Indication ValueRL - Radio LinkRL - Return Loss RLC - Control PDURLC - Radio Link ControlRLC - reference ECANS projectRLF - Radio Link FailureRLP - Radio Link ProtocolRLS - Recursive Least SquaresRLT - Regimental Landing TeamRM - Rate MatchingRM - Redundancy ManagementRM - Reference ModelRMC - Reference Measurement ChannelRMC - Resource Management CommitteeRMD - Required Markup Declaration (XML)RMON - Remote MonitorRMP - Rooted Multi-PointRMS - Root Mean SquareRNC - Radio Network ControllerRNL - Radio Network LayerRNOSC - Regional Network Operations and Security CenterRNS - Radio Network SubsystemRNTI - Radio Network Temporary IdentifierRNTP - Relative Narrowband Transmit PowerROCC - Range Operations Control CenterROHC - RObust Header CompressionROM - Rough Order of MagnitudeROSA - Receiver Optical Sub-assembly Roscosmos - Russia Federal Space AgencyRoT - Rise over Thermal RPCU - Remote Power Control UnitRPF - RePetition FactorRPH - Resource-Priority HeaderRPM - Route Processing Module

RPR - Resilient Packet RingRPSF - Rotation, Processing & Surge FacilityRRC - Radio Resource ControlRRC - Root Raised CosineRRM - Radio Resource ManagementRS - Reference SignalRSA - Russian Space AgencyRSC-E - Rocket Space Corporation-EnergiaRSCP - Received Signal Code PowerRSE - Reliable Software EngineeringRSG - Remote Support GatewayRSP - Route Switch ProcessorRSRM - Reusable Solid Rocket MotorRSRM/B - Reusable Solid Rocket Motor/BoosterRSRP - Reference Signal Received PowerRSRP - Reference Symbol Received PowerRSRQ - Reference Signal Received QualityRSSC - Regional SATCOM Support Center RSSI - Received Signal Strength IndicatorRSTP - Rapid Spanning Tree ProtocolRSU - Remote Switching UnitRSVC - Russian ServicesRSVG - Russian Services GroupRSVP - repondez s'il vous plait (please reply)RT - Round TripRTCH - Research and TechnologyRTCP - Real-time Transport Control ProtocolRTCP - RTP Control ProtocolRTD - Round-Trip DelayRTF - Return to FlightRTP - Real-time Transport ProtocolRTS - Real Time ServicesRTS - Routing And Translation ServerRTT - Responsible Test OrganizationRTT - Round Trip TimeRTU - Remote Test Unit (NQMSfiber OSS)RUNI - Remote UNI (User Network Interface)RV - Redundancy VersionRx - ReceiveRxD - Receive Diversity S&A - reference ECANS projectS&NM - Systems & Network ManagementS-GW - Serving GateWayS-KPI - Service (or Subscriber) KPIS-MCCH - Secondary Multicast Control CHannel S-Tag - Service VLAN TagS-Tag - Service VLAN TagS-TMSI - SAE Temporary Mobile Subscriber IdentityS-TMSI - System Architecture Evolution - Temporary Mobile Subscriber IdentityS-VLAN - Service VLAN (also referred to as provider Vlan)S-VLAN ID - The 12 bit VLAN ID field in the S-Tag of an ENNI frameS/P - Serial-to-Parallel S1 - The interface between an eNodeB and the Core Network (CN)

S1-AP - S1 Application ProtocolS1-U - S1 User planeS5 - The interface between a Serving-GateWay (S-GW) and a Packet Data Network GateWay (P-GW) in the same Public Land Mobile Network (PLMN)S8 - The interface between a Serving-GateWay (S-GW) and a Packet Data Network GateWay (P-GW) in a different Public Land Mobile Network (PLMN)SA - Service AgentSA - Situational AwarenessSA - Spacecraft AdapterSA - stand-aloneSAA - satellite access authorization SAAS - Software As A ServiceSABI - Secret and Below Interoperability InitiativeSABM - Set Asynchronous Balanced ModeSAE - System Architecture EvolutionSAFB - Schriever Air Force BaseSAIC - Science Applications International CorporationSAL - security access levelSAMPEX - Solar Anomalous and Magnetosphere Particle ExplorerSAN - Storage Area NetworkSAO - Smithsonian Astrophysical ObservatorySAP - Service Access PointSAP - Software Brand NameSAPI - Service Access Point IdentifierSAR - satellite access request SAS - Serial-Attached SCSI SATA - Serial Advanced Technology Attachment SATCOM - satellite communications SAToP - Structure-Agnostic TDM over PacketSAW - Stop-And-WaitSBC - Session Border ControllerSBM - Satellite Broadcast ManagerSBRY - Southbury, CTSBU - Sensitive, But UnclassifiedSC - Single CarrierSC-FDMA - Single Carrier - Frequency Division Multiple AccessSC2C - Satellite Command and Control Center SCAWG - Space Communications Architecture Working GroupSCD - Small Conversion DeviceSCDS - Space Communications and Data SystemsSCH - Synchronization CHannelSCI - Sensitive Compartmented InformationSCIF - SCI facilitySCIP - Secure Communications Interoperability ProtocolSCM - Spatial Channel ModelSCME - Spatial Channel Model - ExtensionSCN - Switched Circuit NetworkSCP - Service Control Point (IN)SCP - Session Control Protocol (protocol)SCP - Secure CoPy (UNIX)SCS - Session Control and SignalingSCSI - Small Computer System InterfaceSCTP - Stream Control Transmission ProtocolSD - Service Director

SDB - SATCOM Data Base SDC - System Management/Display & Control/Communication & TrackingSDF - Service Data FlowSDF - Service Data Flows SDH - Synchronous Digital Hierarchy SDIL - Software Development and Integration LabSDMA - Space (or Spatial) Division Multiple AccessSDMA - Spatial Division Multiple AccessSDN - Services Delivery NodeSDN - Subscriber Directory NumberSDO - Standards Development OrganisationSDU - Service Data UnitSEA - Subscriber Experience AnalyzerSECDEFCOM - Secretary of Defense CommunicationsSECN - Survivable Emergency Conferencing NetworkSEFS - Severely Errored Framing SecondsSEI - Secure End InstrumentSEM - Spectrum Emission MaskSERDES - Serializer/Deserializer SES - Severely Errored SecondsSESR - Severely Errored Seconds RatioSEWP - Scientific and Engineering Workstation ProcurementSF - SuperFrameSFAL - Sioux Falls, (site of EROS Data Center)SFBC - Space-Frequency Block CodeSFDR - Spurious-Free Dynamic RangeSFF - Small Form Factor SFG - Special Function GatewaySFN - System Frame NumberSFP - Small Form-factor Pluggable SG - Signaling GatewaySGS - Svalbard Ground StationSGSN - Service GPRS Support Node SGW - serving gateway SHDSL - Symmetric High-Bit-Rate Digital Subscriber Loop, G.shdslSHF - super high frequency SI - Service IndicatorSI - Service Interworking (e.g. SI-NNI)SI - Study ItemSI - System InformationSI-1 - System Information message 1 SI-NNI Service Interworking NNISI-RNTI - System Information Radio Network Temporary Identifier (RNTI)SIAP - Systems Integrated Analysis PlanSIB - Status Indication BusySIB - System Information BlockSIC - Successive Interference CancellationSID - shared information / data SiGe - Silicon Germanium SILC - Selective Incoming Load ControlSIM - Subscriber Identity ModuleSIMO - Single Input Multiple OutputSINET - Science Information NetworkSINR - Signal to Interference plus Noise Ratio

SIO - Status Indication Out - of AlignmentSIO - Systems Integration OfficeSIP - Session Control ProtocolSIP - Session Initiation ProtocolSIPO - Signal Units Indicating Processor OutageSIPRNET - Secret Internet Protocol Router NetworkSIPS - Session Control Protocol SecureSIR - Signal to Interference RatioSISO - Single-Input Single-OutputSISO - Soft-Input Soft-OutputSLA - Service Level AgreementSLO - Service Level ObjectiveSLT - Signaling - Link TestSLTE - Signaling Link Terminal Equipment SM - Service ModuleSMB - Small and Medium size Businesses SMC - Security Mode CommandSMDC - Space and Missile Defense Command SMDC/ARSTRAT - U. S. Army Space and Missile Defense Command / U. S. Army Forces Strategic Command SMEO - Small / Medium End OfficeSMEO - Small End OfficeSMF - Single Mode Fiber SMS - Short Message ServiceSMS - Spectrum Monitoring System SMU - Switch Multiplexer UnitSN - Sequence NumberSN - Service NodeSN - Service Node InterfaceSN - Space NetworkSN-PDU - SubNetwork Dependent Convergence Protocol Protocol Data UnitSNASS - Space Network Scheduling SystemSND - Sequence Number DownSNDCP - SubNetwork Dependent Convergence ProtocolSNMP - Simple Network Management ProtocolSNMPv2 - Simple Network Management Protocol Version 2SNMPv3 - Simple Network Management Protocol Version 3SNOW3G - A stream-cipher algorithm available in UMTS and LTESNR - Signal-to-Noise RatioSNU - Sequence Number UpSO - Segmentation OffsetSO - Service OrderSOA - Service Oriented Architecture SOAM - Service OAMSOAM-PDU - Service OAM frames or PDUSOAP - Simple Object Access ProtocolSOC - Service Operations CenterSOCC - Satellite Operations Control CenterSOCOM - United States Special Operations CommandSOFDMA - Scalable Orthogonal Frequency Division Multiplexing AccessSOFIA - Stratospheric Observatory for Infrared AstronomySOHO - Small Office Home Office SOHO - Solar and Heliosperic ObservatorySOMD - Space Operations Mission Directorate

SON - self-optimizing networksSON - Self-Optimizing/Organizing NetworkSONET - Synchronous Optical Network SOP - Standard Operating ProcedureSOS - System of SystemsSOUTHCOM - United States Southern CommandSP - Service Provider SPAWAR - Naval Space Warfare Systems CenterSPC - Signal Point CodeSPCS - Space Control Squadron SPCS/OS - Stored Program Control System/Operations SystemsSPDU - Secondary Power Distribution UnitSPECTRUM - SPECTRUM (TTS)SPID - Subscriber Profile IDentity for Radio Access Technology / Frequency Selection PrioritySPL - Sound Pressure LevelSPRM - Supplemental Performance Report MessageSPRT - Simple Packet Relay TransportSPS - Semi-Persistent SchedulingSPS-C-RNTI - Semi-Persistent Scheduling Cell- Radio Network Temporary IdentifierSQL - Structured Query LanguageSQM - Service Quality ManagementSR - Scheduling RequestSRB - Signalling Radio BearerSRB - Solid Rocket BoosterSRD - Systems Requirements DocumentSRLG - Shared Risk Link GroupSRM - Service Reference ModelSRNC - Serving Radio Network ControllerSRNS - Serving Radio Network SubsystemSRRM/B - Shuttle Reusable Rocket Motor/BoosterSRS - Service Request SystemSRS - Sounding Reference SignalsSRTCP - SRTP Control ProtocolSRTP - Secure Real Time ProtocolSRTP - Secure Real time Transport ProtocolSRVCC - Single Radio Voice Call Continuity (VCC)SS - SoftswitchSS - System SimulatorSS7 - Signaling System Number 7SSC - Secondary Synchronization CodeSSC - Stennis Space CenterSSCI - Stennis Space Center-institutionalSSE - State Signaling EventSSH - Secure SHellSSL - Secure Sockets LayerSSM - Single System ManagerSSM - Strategic SATCOM Manager SSM - Synchronization Status MessageSSME - Space Shuttle Main EngineSSP - Service Switching PointSSPF - Space Station Processing FacilitySSRC - Synchronization Source

SSS - Secondary Synchronization SignalSSS - System/Segment SpecificationSSS_RA - Secondary Synchronization Signal - to - Reference Signal Energy Per Resource Element RatioST - Star TrackerSTAN - Stanford UniversitySTBC - Space-Time Block CodeSTC - Space Time CodingSTE - Secure Terminal EquipmentSTEP - Standard Tactical Entry PointSTEP - Standardized Tactical Entry Point STP - Signal Transport PointSTP - Spanning Tree ProtocolSTRATCOM - United States Strategic CommandSTS - Space Transportation SystemSTS - Synchronous Transport SignalSTTD - Space-Time Transmit DiversitySTU-III Secure Telephone Unit third generation/low-cost terminalSU - Signal UnitSU-MIMO - Single-User Multiple-Input Multiple-OutputSUIT - Suitland, MarylandSUT - System Under TestSVD - Singular-Value DecompositionSVN - Software Version NumberSVS - Secure Voice SystemSVS - Switched Voice ServiceSW - SoftwareSW - SwitchSyncE - Synchronous Ethernet T-ISP Tailored Information Support PlansT-Line - TDM Line serviceTA - Time AlignmentTA - Timing AdvanceTA - Tracking AreaTAC - Tracking Area CodeTAD - Traffic Aggregate DescriptionTAF - Transport Adaptation FunctionTag - an optional field in a frame headerTAI - Tracking Area Identifier TAI - Tracking Area IdentityTALS - TDM Access Line ServiceTANET2 - Taiwan Research Network TASO - Terminal Area Security OfficerTAT - Timing Advance TimerTAU - Tracking Area UpdateTB - Tera ByteTB - Transport BlockTBACS - Token-Based Access Control SystemTBD - To Be DeterminedTBF - Temporary Block FlowTBR - To be reviewedTBS - Transport Block SizeTC - Test CaseTC - Textual Conventions

TCA - Threshold Crossing AlertTCA - Transformational Communications Architecture TCCC - Theater C4 Coordination CenterTCCC - Theater C4I Coordination CenterTCF - Transport Connection FunctionTCH - Traffic CHannelTCI - Tag Control InformationTCP - Transmission Control ProtocolTCP/IP - Transmission Control Protocol/Internet ProtocolTD - Treasury DepartmentTD-SCDMA - Time Division Synchronous Code Division Multiple AccessTDB - To Be DeterminedTDD - Time Division DuplexTDD - Time Division DuplexTDL - Tactical Data LinksTDL - Tapped Delay LineTDM - Time Division MultiplexingTDMA - Time Division Multiple AccessTDR - Time Domain ReflectometryTDRS - Tracking and Data Relay SatelliteTDRS-E - Tracking and Data Relay Satellite, EastTDRSS - Tracking and Data Relay Satellite SystemTE - Terminal EquipmentTE - Transport EquipmentTEAC - Brand NameTEI - Trans Earth InjectionTEID - Tunnel Endpoint IdentifierTEID - Tunneling End IDTEID - Tunnelling End IDentityTF - Transport FormatTFT - Traffic Flow TemplateTG - Trunk GatewayTGRP - Transmission Gap Repetition PeriodTH - Temperature HighTI - Transaction IdentifierTIA - Telecommunication Industries/Industry AssociationTIA - Telecommunications Industry Association TIA - Transimpedance Amplifier TID - Trunk IDTIDY - Temporary DutyTIG - Theater Information GridTIM - Theater Information ManagerTIN - Temporary Identifier used in Next updateTL - Temperature LowTLI - Trans Lunar InjectionTLLI - Temporary Logical Link IdentityTLS - Transport Layer SecurityTLV - Type, Link, ValueTM - Transparent ModeTMA - Tower Mounted AmplifierTMA - TRICARE Management ActivityTMCS - Teleport Management and Control System TMD - Transparent Mode DataTMF - TeleManagement Forum

TMN - Telecommunications Management NetworkTMOS - TSAT Mission Operations System TMS - Telephony Management SystemTMS - Trouble Management SystemTNA - Technology Neutral Architecture TNA - Training Needs AnalysisTNC - Theater NetOps Center TNL - Transport Network LayerTNM - Telecommunications Management Network TO - Technical OrderTOAD - Software editing toolTOMS - Total Ozone Mapping SpectrometerTOPEX - The Ocean Topography ExperimentTOR - Terms of ReferenceTOS - Type Of Service (presently differentiated services code point / DSCP)TOSA - Transmitter Optical Sub-assembly TPC - Transmitter Power ControlTPC-PUCCH-RNTI - The Radio Network Temporary Identifier (RNTI) used for sending Transmitter Power Control (TPC) commands applicable to the Physical Uplink Shared CHannel (PUCCH). TPC-PUSCH-RNTI - The Radio Network Temporary Identifier (RNTI) used for sending Transmitter Power Control (TPC) commands applicable to the Physical Uplink Shared CHannel (PUSCH). TPD - Total Power De-ratingTPFDD - Time Phased Forces Deployment DataTPMI - Transmitted Precoding Matrix IndicatorTPOCC - Transportable Payload Operations Control CenterTPPU - Task, Post, Process, UseTR - Technical ReportTR - Telecom RequestTR - Telecommunications Request TRADOC - Training and Doctrine CommandTRAN - TRANsport layerTRANSCOM - United States Transportation CommandTrCH - Transport CHannel TrCP - Traffic Conditioning PointTRD - Technical Requirements DocumentTRI-TAC - Tri-Services Tactical CommunicationsTRMM - Tropical Rainfall Measuring MissionTRO - Tailored Readiness OptionsTRR - Test Readiness ReviewTRX - Transciever / Transmiter ReceiverTS - Tandem SwitchTS - Technical SpecificationTS - TOP SECRETTSAT - Transformational Satellite Communications System TSC - Telescience Support Center TSC - Test System ControllerTSEC - Telecommunications SecurityTSG - Technical Specification GroupTSO - Telecommunication Service Order TSP - TDM Service ProcessingTSP - Telecommunications Service Priority

TSRS - Telecommunications Service RequestsTSSI - Telecom Switched Services InteroperabilityTSTD - Time-Switched Transmit DiversityTT - Test ToleranceTT - Trouble TicketTT&C - Telemetry, Tracking and CommandTT&P - Techniques, Tactics, and ProceduresTTA - Telecommunications Technology AssociationTTC - Telecommunication Technology CommitteeTTF - Trail Termination FunctionTTI - Transmission Time IntervalTTI - Transmission Time IntervalTTR - Time To RestoreTTS - Trouble Ticket SystemTU - Tributary UnitTU - Typical UrbanTUG - Tributary Unit GroupsTVA - reference ECANS projectTVC - Thrust Vector ControlTx - TransmitTxD - Transmit DiversityU-PE - Unclassified Provider EdgeU-plane - User planeUAC - User Agent ClientUAH - University of Alabama, HuntsvilleUARC - University Affiliated Research CenterUARFCN - UTRA Absolute Radio Freequency Channel NumberUARS - Upper Atmospheric Research SatelliteUAS - Unavailable SecondsUAS - User Agent ServerUCI - Uplink Control InformationUCPT - Ultra High Frequency Follow-on Communications Planning Tool UCR - Unified Communications RequirementsUDDI - Universal Description, Discovery, and IntegrationUDP - User Datagram ProtocolUE - User EquipmentUE-AMBR - UE Aggregate Maximum Bit-RateUEA2 - A new ciphering algorithm to be deployed in UMTS Release 7 as an insurance policy against the original UMTS Kasumi-based cyphering scheme being cracked in the futureUEUT - User Equipment Under TestUFO - Ultra High Frequency Follow-on UFO/E - UHF Follow-on (Enhanced) UFS - User Features and ServicesUHF - ultra high frequency UICC - Universal Integrated Circuit CardUL - UpLinkUL - SCH Uplink Shared ChannelUL - TFT - Uplink TFTULAF - Universal Line Access FamilyULH - Ultra Long Haul UM - Unacknowledged ModeUMA - Unlicensed Mobile AccessUMD - Unacknowledged Mode Data

UML - Unified Modeling LanguageUMTS - Universal Mobile Telecommunications SystemUMUX - Universal MultiplexerUN - United NationsUNI - User (to) Network InterfaceUNI - user-network interface UNI-C User Network Interface C (Customer)UNI-EVC-ID - a UNI service attributeUNI-identifer - a UNI service attributeUNI-list - a UNI service attributeUNI-MTU - the maximum sized service frame allowed at the UNIUNI-N User Network Interface N (Network)UNITeS - Unified NASA Information Technology ServicesUP - Unitary PrecodingUPA - Universal Powerline Association UPE - User Plane EntityUpPTS - Uplink Pilot Time SlotUPS - Uninterruptible Power SupplyUPSR - Unidirectional Path-Switched RingUpTS - Uplink Time SlotURI - Uniform Resource IdentifierURL - Universal Resource LocatorURN - Uniform Resource NameURRP-MME - UE Reachability Request Parameter for the Mobility Management EntityUS - Upper StageUSA - United Space AllianceUSA - United States ArmyUSAF - United States Air ForceUSCG - United States Coast GuardUSD - Under Secretary of DefenseUSE - Upper Stage EngineUSFK - United States Forces (Korea)USGS - United States Geological SurveyUSIM - Universal Subscriber Identity ModuleUSMC - United States Marine CorpsUSN - United States NavyUSNORTHCOM - United States Northern Command USSTRATCOM - United States Strategic Command USUHS - Uniformed Services University of the Health Sciences UTA - UNI Tunnel AccessUTC - coordinated Universal TimeUTP - Unshielded Twisted PairUTRA - Universal Terrestrial Radio AccessUTRAN - UMTS Terrestrial Radio Access NetworkUTRAN - Universal Terrestrial Radio Access NetworkUu - The radio interface between the eNodeB and the User equipment (or, in the case of UMTS, between the nodeB and the UE)UUID - Universally Unique IDentifer (RFC 4112)UUNET - Internet Service Provider - Company NameV-PCRF - Visited Policy Control and Charging Rules FunctionV-TAG - VLAN Tagging a.k.a frame tagging to help identify "trunk" linksVA - Vulnerability AssessmentVAB - Vehicle Assembly Building

VAFB - Vandenberg Air Force BaseVBNS+ - Very high speed Backbone Network Service VBScript - Visual Basic ScriptVC - Virtual Circuit VC - Virtual ContainerVCAO - Voice Connection Approval OfficeVCAT - Virtual ConCAtenationVCB - Virtual Circular BufferVCC - Voice Call ContinuityVCI - Virtual Channel IdentifierVCO - Voltage-Controlled OscillatorVCR - Video Cassette RecorderVCRM - Verification Cross Reference Matrix VCRS - Video Conferencing Reservation SystemVCSEL - Vertical Cavity Surface Emitting Laser VDC - Volts Direct CurrentVDNC - Virtual NASA Data CenterVGD - Video Graphics DisplayVGW - Video GatewayVH - Higher extreme VoltageVHF - very high frequencyVID - VLAN IdentificationViIP - Video over Internet ProtocolViTS - Video Teleconference ServiceVL - Lower extreme VoltageVLAN - Virtual Local Area NetworkVLL - L2 MPLS VPNVLR - Visitor Location RegisterVOD - Video On Demand VOIP - Voice Over Internet ProtocolVoIP - Voice over Internet ProtocolVoIP - Voice over IP VOP - Voice Over PacketVoSIP - Voice over Secure Internet ProtocolVOSIP - Voice Over Secure IPVoTS - Voice Teleconferencing ServiceVP - Virtual PathVPF - Vertical Processing FacilityVPLMN - Visited PLMNVPLMN - Visited Public Land Mobile NetworkVPLS - MPLS L2 VPNVPLS - Virtual Private LAN Service VPN - Virtual Private NetworkVPS - Voice Protection SystemVPWS - Virtual Private Wire ServiceVRA - Video Roll-About (video conferencing system)VRB - Virtual Resource BlockVRB - Virtual Resource Blocks VRRP - Virtuel Router Redundancy ProtocolVSAL - variable security access levelVSS - Voice Switching SystemsVSU - Video Session UnitVT - Virtual TributaryVTC - Video Teleconferencing

VTP - VLAN Trunking ProtocolVUNI - Virtual (C-tagged) User Network InterfaceUNI - Virtual UNI (User Network Interface)W-ASAC - WAN Level ASACW-CDMA - Wideband Code Division Multiple Access WACO - Waco, TXWAN - Wide Area NetworkWANR - Wide Area Network ReplacementWAP - Wireless Access Protocol / Wireless Access PointWARNORD - WARNing ORDerWCDMA - Wideband Code Division Multiple AccessWCF - Windows COmputing FoundationWDISC - WSC Data Interface Service CapabilityWDM - Wave Division Multiplexing WFF - Wallops Flight FacilityWG - Working GroupWGS - Wallops Ground StationWGS - Wideband Global System WHS - Washington Headquarters ServiceWi-Fi - Wireless FidelityWiMax - Wireless Maximum WiMAX - Worldwide Interoperability for Microwave AccessWIN-T - Warfighter Information Network - Tactical WIND - SpacecraftWINS - Windows Internet Naming ServicesWKQI - Weighted Key Quality IndicatorWLAN - Wireless Local Area Network WLAN - Wireless Local Area NetworksWLPS - Wallops IslandWPC - Wireless Packet CoreWSC - White Sands ComplexWS-Security - Web Services SecurityWSS - Web Services SecurityWSDL - Web Services Description LanguageWSMR - White Sands Missile RangeWSOC - Wideband SATCOM Operations Center WSTF - White Sands Test FacilityWTR - Wait To RestoreWWSVCS - Worldwide Secure Voice Conferencing SystemWWW - World Wide WebWY - WY is the amount of traffic accepted as yellow over the time interval T that may be delivered to the egress UNIX-MAC - X Message Authentication CodeX2 - The interface used to interconnect eNodeBsX2-C - X2 Control planexCH_RA - xCHannel to Reference Signal Energy Per Resource Element ratioXENPAK - 10-Gigabit Enhanced Package XFP - 10-Gigabit Form factor pluggable module XID - eXchange IDentificationXML - Extensible Markup LanguageXO - Company NamexSTP - Spanning Tree Protocol (multiple variations)XTE - X-ray Timing ExploreZC - Zadoff-Chu

ZCZ - Zero Correlation ZoneZF - Zero-Forcing