duplex telegraph

- dial telegraph
- docking telegraph
- duplex telegraph
- electric telegraph
- electronic telegraph
- engine telegraph
- facsimile telegraph
- frequency telegraph
- high-frequency carrier telegraph
- infra-acoustic telegraph
- letter-printing telegraph
- multichannel voice-frequency telegraph
- multiple telegraph
- narrow-band type-letter telegraph
- office telegraph
- phase telegraph
- picture telegraph
- roll telegraph
- searchlight telegraph
- ship electric telegraph
- start-stop telegraph
- steering telegraph
- superacoustic telegraph
- tape telegraph
- tone telegraph
- type-writing telegraph
- voice-frequency telegraph
- wire telegraph
- wireless telegraph

- active equipment
- airborne-electrooptical equipment
- amplifying equipment
- amplitude-modulation equipment
- analog-facsimile equipment
- audio equipment
- audio-visual equipment
- automatic-answerback equipment
- automatic-switching equipment
- auxiliary audio equipment
- backup equipment
- built-in equipment
- cable-input equipment
- calling equipment
- channel-dividing equipment
- channel-multiplexing equipment
- ciphony equipment
- command-data equipment
- communication security equipment
- COMSEC equipment
- conference communication equipment
- container-point communication equipment
- control-signaling equipment
- cross equipment
- customer-premises equipment
- data-circuit terminating equipment
- data-communication equipment
- data-compression equipment
- data-processing equipment
- data-terminal equipment
- data-transcription equipment
- data-transmission equipment
- dialing equipment
- dial-switching equipment
- digital-facsimile equipment
- digital-intercontinental conversion equipment
- domestic radioelectronic equipment
- duplex telegraph exchange equipment
- duplex universal trunking equipment
- emergency automation equipment
- explosion-proof equipment
- facsimile-telegraph equipment
- field equipment
- FIP equipment
- floor equipment
- grandfathered-terminal equipment
- ground communication equipment
- hoister-to-cage communication equipment
- hydroacoustical equipment
- image pick-up equipment
- inductive communication equipment
- industrial RF-equipment
- information technology equipment
- in-plant equipment
- input/output equipment
- input-and-monitoring equipment
- interface equipment
- intermediate conversion equipment
- ISDN-compatible equipment
- letter-printing fidelity increasing equipment
- limited-protection voice equipment
- line path equipment
- loudspeaking fireproof communication equipment
- magnetic-drum receiving equipment
- marine radiocommunication equipment
- medical electric equipment
- medical RF-equipment
- mine's exchange equipment
- movable HF-communication equipment
- network termination equipment
- new-customer premises equipment
- nonstationary equipment
- operative communication equipment
- photofacsimile equipment
- portable equipment
- protection equipment
- radioelectronic aircraft equipment
- radioelectronic satellite equipment
- radiopoint equipment
- radiotelegraph equipment
- railway-crossing communication equipment
- remote announcement equipment
- remote control equipment
- repeating equipment
- scientific RF-equipment
- security equipment
- selective communication equipment
- selective digital call equipment
- service equipment
- service-channel equipment
- signal-equalizing equipment
- signal-generating equipment
- signal-processing equipment
- sound transmission equipment
- spark-safe digital communication equipment
- stand-alone radiotelephone system equipment
- standard channel derivation equipment
- start-stop synchronous equipment
- station equipment
- studio equipment
- submarine communication equipment
- subscriber equipment
- switching equipment
- telecine equipment
- telecontrol equipment
- telegraph equipment equipment
- telemechanic equipment
- telemonitoring equipment
- terminal equipment
- testing-measuring equipment
- thirty-channel digital equipment
- through-group equipment
- through-supergroup equipment
- tone-telegraphing equipment
- transmission equipment
- TRI-TAC equipment
- trunking equipment
- USB-communication marine equipment
- USB-communication water transport equipment
- VHF radiotelephone two-way equipment
- video equipment
- wire diving communication equipment
- wireless diving communication equipment

- administrative-economic communication
- advanced shipboard communication
- aerial communication
- aeronautical communications
- air steward-to-air steward telephone communication
- airborne SHF-communication
- airborne-to-Earth communication
- aircraft communication
- air-to-air communication
- air-to-air voice communication
- air-to-ground electric communication
- Airways and Air communications
- all-mine telephone communication
- analog tropospheric communication
- analog-to-digital communication
- annunciating communication
- antenna communication
- asynchronous communication
- audio-conference communication
- audio-visual communication
- auroral long-distance communication
- automatic trunk communication
- auxiliary communication
- babyphone communication
- basic communication
- bathysphere-to-carrier-ship communication
- bidirectional communication
- binary-synchronous communication
- boat emergency communications
- both-way simultaneous communication
- branch telephone communication
- broadcast communication
- carrier-current communication
- car-to-car communication
- coastal center-to-coastal center communication
- code-independent data communication
- coherent-light communication
- combine wall communication
- command-telephone communication
- common-service communication
- common-using telegraph communication
- common-using telephone communication
- component triaxial communication
- computerized communication
- computer-to-computer communication
- conductor-to-departure responsible communication
- conference communication
- confidential special radio communication
- contact network communication
- contactless HF-communication
- contingency communication
- continuous communication
- control communication
- data communication
- data-transmission communication
- departmental engineering communication
- departmental telegraph communication
- digital communication
- digital-speech communication
- direct communication
- direct-pair communication
- direct-telephone communication
- disaster communication
- dispatch communication
- display communication
- distress communication
- district-by-district communication
- diversity communication
- diver-to-diver communication
- diving-service communication
- document electric communication
- documental conference communication
- duplex communication
- duplex radiotelephone communication
- Earth-to-airborne communication
- Earth-to-satellite communication
- Earth-to-space-to-Earth communication
- either-way communication
- electrical communication
- electromagnetic communication
- electronic communication
- emergency communication
- emergency ship radio communication
- enciphered-facsimile communication
- engineering station communication
- engineering-telephone communication
- everyone-to-everyone communication
- face communication
- fast-acting telephone communication
- fire-place communication
- fixed aeronautical communication
- fixed-electric communication
- fleet communication
- frequency-hop communication
- gateway-to-gateway communication
- ground-line communication
- group engineering communication
- half-duplex communication
- harmonic communication
- H-carrier communication
- HF-communication
- high-speed mobile communication
- house-car communication
- hydroacoustic communication
- incoming communication
- inductive mines communication
- industrial communication
- industrial-automatic communication
- industrial-engineering communication
- in-plant communication
- interaction communication
- interpaging communication
- interstation communication
- interstellar communication
- intersystem communication
- intraairplane telephone communication
- intrabasin selector communication
- intrabasin telegraph communication
- intrabasin telephone communication
- intrairport communication
- intraship communication
- intratrain telephone communication
- irregular communication
- isochronous communication
- land mobile communication
- land-to-space communication
- letter-printing communication
- lighting wire communication
- line communication
- line-path communication
- line-track telephone communication
- littoral radiotelephone communication
- local common service communication
- local engineering communication
- local telephone communication
- long-haul communication
- long-haul fiber-optical communication
- long-haul telephone communication
- loud-speaking communication
- main conference communication
- main engineering communication
- main radio communication
- manoeuvre radio communication
- man-to-machine communication
- marine communication
- marine facsimile communication
- meteor-burst communication
- meteoric-ionospheric communication
- microwave communication
- militarized guard communication
- mobile aeronautical communication
- mobile communication
- moon-bounce communication
- moorage-by-moorage communication
- movable communication
- MT administration-to-road communication
- multicast communication
- multichannel communication
- multimedia communication
- multiple channel class A communication
- multiple channel class B communication
- multiple channel class C communication
- multiple channel system radio communication
- multipoint communication
- navigating-service communication
- n-way communication
- office communication
- operative communication
- operative-dispatch communication
- operative-managing communication
- operative-repairing communication
- operator-to-train mobile communication
- oral communication
- outgoing communication
- packet communication
- passband data communication
- passenger-to-locomotive driver communication
- passenger-to-policemen communication
- phase-locked communication
- phototelegraph communication
- pilot-to-steward telephone communication
- plane-to-plane communication
- platform announcing communication
- platform radio communication
- platform-to-train mobile communication
- point-to-point communication
- power dispatch communication
- power line communication
- private bypass communication
- private-branch communication
- private-branch industrial communication
- pulse communication
- radial communication
- radial-aerial USB-communication
- radio link communication
- radio relay communication
- radio searching communication
- radiotelephone communication
- railway telephone communication
- real-time communication
- recording communication
- regional communication
- regular communication
- remote reference communication
- road communication
- road engineering communication
- road managing communication
- road power dispatch communication
- road service dispatch communication
- road servicing communication
- road telegraph communication
- rural communication
- safety communication
- satellite marine communication
- satellite-to-Earth communication
- satellite-to-satellite communication
- SB communication
- secure communication
- selector communication
- service communication
- service dispatch communication
- service section communication
- SHF-wave communication
- ship coastal facsimile communication
- ship-driver-to-ship-driver communication
- ship-radio communication
- ship-telephone communication
- ship-to-ship communication
- ship-to-spacecraft communication
- ship-to-submarine communication
- shore-to-ship communication
- short-band communication
- simplex communication
- simplex single-frequency communication
- simplex stripping communication
- simplex two-frequency communication
- single-channel communication
- single-frequency radio communication
- single-hop communication
- single-side loudspeaking communication
- sky-wave communication
- slope telephone communication
- sonic communication
- space communication
- space laser communication
- spacecraft-to-subscriber communication
- space-to-space communication
- special communication
- speech communication
- static-wire communication
- station communication
- station inductive communication
- station mobile communication
- station-by-station telephone communication
- station-radio communication
- steering cab-to-captain's cab communication
- steering cab-to-power dispatchboard communication
- steering cab-to-tiller compartment communication
- submarine laser communication
- submarine sound communication
- submarine TV-communication
- submarine-to-satellite communication
- submarine-to-submarine communication
- subscriber-to-workgroup communication
- switch point communication
- synchronous communication
- telegraphic communication
- telegraphic-telephone radio communication
- telephonist-to-diver communication
- telex communication
- ticket-dispatch communication
- time-bill communication
- train dispatch communication
- train inductive communication
- train radio communication
- train radiotelephone communication
- train radiowire telephone communication
- train-interstation communication
- train-master-to-station-master assistant communication
- train-master-to-train team communication
- train-to-movable object communication
- train-to-train radio communication
- transport police communication
- tropospheric communication
- tropospheric-scutter communication
- trunk communication
- tunnel train radio communication
- twilight scutter communication
- two-frequency radio communication
- two-side loudspeaking communication
- two-way alternative communication
- two-way simultaneous communication
- ultrasonic communication
- ultraviolet communication
- underground communication
- undersea optical communication
- underwater communication
- unwired earth current communication
- USB-communication
- variable frequency sync communication
- vehicle-to-vehicle communication
- videoconference communication
- videotelephone communication
- voice communication
- wagon-to-wagon mobile communication
- wall communication
- waterside communications
- waterside USB-communication
- wave conducting communication
- wire port communication
- wire radio communication
- wire telephone communication
- workgroup-to-workgroup communication
- world-wide telephone communication

- acoustic alarm system
- acoustic image system
- acoustic systems
- actiontrack system
- active IR-system
- actuator system
- adaptive communication system
- adaptive teleinformation system
- adaptive telemetering system
- advanced information system
- Afsatcom system
- air system
- aircraft intercommunication system
- airfield communication system
- air-ground automatic system
- airline reservation system
- air-to-ground TV system
- alarm signal system
- alarm system
- all-channel signaling system
- ALL-IN-ONE system
- alphanumeric system
- amplified speaker system
- amplitude shift-keying system
- AMPS system
- analog cellular communication system
- analog cellular system
- analog component video system
- analog television system
- analog tropospheric system
- anisochronous system
- antenna system
- antitheft system
- AR system
- Arabsat system
- ASK system
- associated channel analog system
- asynchronous address communication system
- audio recording system
- Aurora system
- Aussat system
- automatic communication system
- automatic connection establishment system
- automatic control system
- automatic data acquisition system
- automatic telegraphy system
- automatic telephone system
- automatic tuning system
- automatized cellular system
- auxiliary alarm system
- balanced cable transmission system
- band sharing system
- base station system
- baseband system
- basic input/output system
- bass-reflex speaker system
- batch processing system
- batch transmission system
- batch-and-forward system
- batteryless system
- bilateral CTV system
- binary tariff system
- biocontrol system
- bit parallel interface system
- bit transport system
- bridge duplex system
- broadband mobile system
- broadcast satellite system
- broadcasting delivery media systems
- burglar alarm system
- byte-serial interface system
- cabinet system
- cabinetless system
- cable distribution system
- cable TV system
- call-accounting system
- call-answering system
- call-counting system
- call-distributing system
- call-processing system
- call-queueing system
- camp-on system
- CAPTAIN system
- car component audio system
- carrier reinsertion system
- carrier system
- carrier-communication system
- carrier-current communication system
- Cassegrain-Schmidt system
- cassette recording system
- cassette reproducing system
- CATRIN system
- caution system
- CD 900 system
- cellular system
- cellular-radio system
- central-battery system
- centralized control system
- chirp binary telegraph system
- cipher system
- circuit switched telecommunication system
- circuit switching telecommunication system
- circular telecontrol system
- clock system
- closed-circuit communication system
- closed-circuit telegraph system
- closed-numbering system
- code-dependent system
- code-division multiple access system
- code-independent system
- code-insensitive system
- code-sensitive system
- coding system
- coherent fiber-optic system
- collimating system
- collocated system
- color separating system
- combined numbering system
- combined power supply system
- combined satellite communication system
- common-battery system
- common-carrier system
- common-channel signaling system
- common-engineering communication system
- common-purpose cellular system
- common-using band system
- common-using cordless telephone system
- common-using paging system
- communication system
- communication traffic system
- communications system
- community antenna system
- community antenna television system
- community TV-system
- commununication switching system
- compact disk digital audio system
- compatible color television system
- compatible single sideband system
- compatible single-band system
- compatible TV-system
- complex radio communication system
- computer vision system
- computer-telephone system
- Comsar system
- Comsat system
- Conax system
- concentrated-insonation system
- conference system
- conference-communication system
- congested system
- congress-class system
- constant-current system
- control generating system
- conventional television system
- Conversant system
- cordless-communication system
- crossbar system
- crossed-coincident microphone system
- Crosspoint system
- CSE system
- C-system
- cubical video projecting system
- data processing system
- data system
- data transport system
- data-collection system
- data-compression system
- data-exchange system
- dataflow system
- data-gathering system
- data-handling system
- data-measuring system
- data-reduction system
- data-transmission system
- Decca Navigator system
- DECfax system
- decision-feedback system
- dedicated control channel system
- dedicated multimedia system
- delta-sigma system
- deluxe presentation system
- departmental communication system
- desktop-video system
- DFS/Copernicus system
- dial-telephone system
- differential phase shift-keying system
- differential-duplex system
- differential-magnetic system
- digital camera system
- digital hybrid-key telephone system
- digital mass storage system
- digital microwave radio transmission system
- digital telephone communication system
- digital transmission system
- digital TV-communication system
- Digital UNIX system
- digital-analog system
- digital-cellular system
- digital-data modulation system
- digital-effect system
- digital-message entry system
- digital-termination system
- direct-broadcasting satellite system
- directing system
- direct-modulation system
- direct-sequence system
- direct-telephone communication system
- discrete communication system
- discrete sound system
- discrete-addressing system
- disk-operating system
- DISOSS system
- dispatch telephone communication system
- dispatch-center system
- dispersed-insonation system
- distributed-insonation system
- distributed-processing system
- documental-type communication system
- Dolby systems
- domestic satellite communication system
- double-band telephone communication system
- double-channel transmission system
- double-current transmission system
- double-pole communication system
- double-sideband large carrier system
- DSCS system
- D-system
- dual-cable system
- dual-reflector system
- duplexed system
- Earth-to-space transmission system
- ECM system
- electric communication system
- electronic antishock system
- electronic data-gathering system
- electronic data-processing system
- electronic-message system
- electronic-scanning system
- electronic-switching system
- Ellipso system
- emergency telephone communication system
- emergency-broadcast system
- EMX system
- equidistant system
- error-correction system
- error-detection system
- Eutelsat system
- extensible system
- external paging system
- facsimile system
- fast-acting servicing system
- fault-tolerant system
- fax communication system
- fax transmitting system
- feed system
- fiber transmission system
- fiber-optic transmission system
- field-sequential system
- final mile system
- finishing system
- fire alarm system
- fire warning system
- first generation cellular system
- five-channel communication system
- fixed satellite system
- Flexcam system
- flexible access system
- Flitsatcom system
- focusing system
- four-channel sound system
- four-dimensional system
- four-wire telephone communication system
- frame-sequential system
- frequency shift-keying system
- frequency-carrier system
- frequency-control system
- front-bass reflex speaker system
- fully digital system
- gate system
- Gaussian system
- generalized system
- generating dynamic system
- generator-dc-motor system
- GIGASET radio system
- global positioning system
- Global system
- Gopher system
- grandfathered system
- group-alerting and dispatching system
- guide system
- hard-wired CCTV system
- hazard system
- helical-scan system
- HF-synchronizing system
- high-precision navigating system
- Hi-linear system
- home system
- home-telephone system
- home-type system
- homing-guidance system
- host system
- hydroacoustic system
- ideal communication system
- idealized system
- image informaion system
- image-forming system
- immedial servicing system
- incompatible system
- independent system
- information retrieval system
- information system radio system
- information system
- information-feedback system
- information-measuring system
- infrared alarm system
- Inmarsat system
- Inmarsat-A system
- Inmarsat-B system
- Inmarsat-C system
- Inmarsat-D system
- Inmarsat-M system
- Inmarsat-P system
- integrated telephone system
- integrated videographic teleconferencing system
- integrated-antenna system
- integrated-communication system
- integrated-modulation system
- integrated-office system
- Intelsat system
- interactive system
- intercarrier-sound system
- intercommunication system
- intercontinental tropospheric system
- interlock system
- intermachine exchange system
- intermediate system
- international communication system
- interphone system
- Intervision system
- intraband signaling system
- intruder alarm system
- inward-outward dialing system
- ionoscatter system
- ionosphere sounder system
- ionospheric system
- Iridium system
- isolated system
- Italsat system
- J-carrier system
- joint-multichannel trunking and switching system
- K-carrier system
- key system
- key-telephone system
- land satellite communication system
- large-grained communication system
- laser communication system
- L-band satellite system
- L-carrier system
- Leasat system
- lightning protection system
- limited distortion system
- line amplifiers system
- link system
- little-channel relay system
- local alarm system
- local battery system
- local communication system
- local radio paging system
- long-haul system
- long-range system
- loop system
- loud-speaking communication system
- low-traffic system
- magnetic tape recording system
- Mail system
- management-information system
- manual cellular system system
- manual telephone set system
- Marisat system
- master television system
- master-antenna television system
- matrix sound system
- message feedback system
- message procession system
- message registration system
- message-switched system
- meteor radio system
- Metrobus system
- micro component system
- Micro Press Cluster Printing system
- micro-lens system
- microprocessor system
- microwave relay system
- midi system
- mine radio telephone system
- mini system
- mixed media system
- mixed numbering system
- mobile cellular communication system
- mobile land communication system
- mobile radio system
- mobile relay system
- mobile system
- modulated system
- monetary mobile system
- MS-Mail system
- multiareal system
- multicassette system
- multichannel telephone system
- multicomputer system
- multidisk system
- multiformat recording system
- multifrequency tone signaling system
- multiguard system
- multilevel mixed system
- multimedia system
- multiple-channel system
- multiqueue system
- Multiscrypt system
- multistandard system
- multitrack editing system
- mutibeam antenna system
- muting system
- Nagravision system
- NAMTS system
- narrow-angle TV system
- national communication system
- navigation system
- n-channel communication system
- n-channel DPSK system
- n-channel transmission system
- network standalone system
- network system
- network-operation system
- networks numbering system
- neutral direct-current telegraph system
- n-head video system
- NMT system
- noise-reduction system
- nonhoming tuning system
- noninterlaced television system
- nonsegmented system
- Norsat system
- n-satellite system system
- n-tone DPSK system
- n-tone MFSK system
- NTSC system
- NTT system
- obligatory message system
- Odyssey system
- off-line system
- on-line computer system
- on-line secured system
- open numbering system
- open system
- operative-engineering communication system
- opposite signals system
- optical-communication system
- optical-information system
- optical-projection system
- optoelectronic system
- oscillating system
- oscillation system
- outband signaling system
- package-and-resource tracking system
- pagemaster system
- paging system
- PAL system
- parametric system
- PATHWORKS system
- pattern recognition system
- personal holding guard system
- phase shift-keying system
- phone system
- Piccolo system
- pilot-controller system
- polar direct-current telegraph system
- portable mobile system
- power control system
- power controlling system
- power-line carrier system
- power-supply system
- press-to-talk system
- Prestel system
- primary-supply system
- privacy system
- private branch paging system
- private movable system
- private videodata system
- private videotex system
- process-interface system
- PROFS system
- programmable cross-connect system
- programmable cross-connected system
- programmed radio system
- prompting system
- protected wireline distribution system
- protection system
- pseudoquadraphony system
- pseudotrunking system
- public videodata system
- public videotex system
- pulse-code system
- pulse-frequency system
- pulse-time system
- quadraphonic sound system
- quadruple-diversity system
- R1 system
- R2 system
- radio buoy system
- radio command system
- radio communication system
- Radio Data system
- radio facsimile system
- Radiocom 2000 system
- radio-control system
- radio-paging system
- radio-relay system
- radiosonde-radio-wind system
- radio-telemetering system
- real time pulse-echo system
- real time system
- receiver lockout system
- recording system
- recovery system
- redundant system
- reference-information system
- regional electronic payment system
- relay-radio system
- remote concentrating system
- remote control system
- remote diagnostic system
- remote information system
- remote semiconcentrating system
- remote sensing system
- remote signaling system
- rendering system
- rerecording system
- reserved servicing system
- RF/Transmission system
- rotary system
- safety alarm system
- safety system
- Satcom system
- satellite comminication system
- satellite marine comminication system
- Satellite Master Antenna Television system
- satellite radio system
- satellite-aircraft communication system
- SB-communication system
- SBL communication system
- scalable system
- scanning trunking system
- SCO UNIX system
- searchless identification system
- seat reservation system
- SECAM system
- second generation cellular system
- second room system
- secondary supply system
- secrecy system
- section communication system
- security system
- segmented system
- seismic system
- selective calling system
- selective frequency base station system
- selective protective system
- selective telephone system
- self-adjusting system
- self-balancing differential system
- self-contained system
- self-test system
- selsyn system
- semiautomatic-switching system
- semiautomatized cellular system
- sensory system
- servo system
- shadow-batch system
- short-haul microwave system
- Sicral system
- Sigma Servo system
- signal system
- simplex movable system
- single-band transmission system
- single-busbar system
- single-cable communication system
- single-cable system
- single-channel system
- single-current transmission system
- single-pulse tracking system
- Skynet system
- small-grained communication system
- SmarTrunk II radio communication system
- solid-state uninterruptible power battery system
- Sony bus system
- sound alarm system
- sound equalization system
- sound navigation system
- sound reinforcement system
- sound warning system
- space-division system
- space-switched system
- spark-safe system
- speaker system
- special communication system
- speech-processing system
- speech-recognition system
- split-speaker system
- spread-spectrum system
- stabilizing system
- stage monitoring system
- standalone double point system
- star-circuit system
- STAREX CMX system
- starting communication system
- start-stop system
- stationary satellite system
- step-by-step system
- stereo sound system
- stereophonic sound system
- storage system
- storage-and-retrieval system
- Strowger system
- submarine fiber-optic system
- subprimary digital transmission system
- subscriber carrier system
- subscriber switching system
- suffix system
- Supersat system
- supervisory control system
- surround sound system
- switched telecommunication system
- switching system
- sync communication system
- synchro system
- synchronous communication system
- synchronous digital system
- TAGS system
- tandem system
- tariffication system
- T-carrier system
- TDF system
- teleautomatic system
- Telecom system
- telecommunication system
- telecommunications system
- telecommunication-service priority system
- telecommunications-service priority system
- telecontrol system
- telemechanic system
- telemetering system
- telemetry system
- telephone system
- telephone-answering system
- telephone-communication system
- telephone-communications system
- teleprocessing system
- Telesat system
- teletex system
- teletypewriter system
- television-telephone system
- Tele-X system
- Telsar system
- terminal system
- terrestrial radio-relay system
- theft-prevention system
- thin-route system
- third generation communication system
- three-axle stabilizing system
- three-channel HF-telephone system
- three-channel transmission system
- three-color system
- three-lens optical system
- three-primary system
- three-wire system
- time-dissemination system
- time-frequency hopping system
- time-switched system
- total access communication system
- total area coverage system
- transmission system
- trichromatic system
- triple-interlace system
- triplex system
- trunk communication system
- TV-observation system
- twelve-channel transmission system
- two-arm system
- two-band system
- two-color system
- two-roller transfer system
- two-step control system
- two-way CATV system
- two-way system
- two-wire telephone communication system
- ultra-match system
- ULTRIX system
- unified radioaccess system
- unilateral-control system
- unilateral-synchronization system
- uninterruptible-power system
- Unisat system
- universal alarm system
- universal-battery system
- universal-electronic system
- universal-movable system
- Uniworks system
- vestigial-sideband system
- video editing system
- video home system
- video recording system
- videocom system
- videoteleconference system
- videotex system
- virtual studio system
- vision system
- vocoder system
- voice dialog system
- voice frequency carrier telegraph system
- voice modulation system
- voice post system
- volume control system
- waiting system
- warning system
- watch system
- watching system
- waterside facsimile communication system
- wave-propagating system
- wide-angle TV system
- Winfax Pro system
- wired broadcasting system
- wireless CCTV system
- wireless home system
- wireless infrared speaker system
- wire-radio communication system
- XY system
- zone-selective protection system
- zoning system

- adjacent channel
- aeronautical emergency channel
- air channel
- air-air channel
- air-ground channel
- allocated channel
- alpha channel
- analog channel
- analog data channel
- associated channel
- associated signaling channel
- asynchronous channel
- audio channel
- automatic's line channel
- auxiliary channel
- average-speed signaling channel
- backward channel
- balanced channel
- band-limited channel
- base cable channel
- base RF-channel
- baseband channel
- B-channel
- bidirectional interaction channel
- bidirectional intercom channel
- binary symmetric channel
- binomial channel
- blank channel
- block multiplexor channel
- blue channel
- branching channel
- brightness channel
- broadband channel
- broadband multiplexing channel
- broadcast TV-radio channel
- buffered I/O channel
- bypass channel
- byte-multiplexor channel
- cable channel
- calling channel
- camera channel
- carrier-current channel
- chroma channel
- chrominance channel
- clear channel
- coherent channel
- color channel
- color-difference channel
- color-sync channel
- common-user channel
- communication channel
- complex high-frequency line channel
- confidence channel
- continuous channel
- continuous-discrete channel
- control channel
- covertness-protected channel
- cue channel
- data transfer channel
- data transmission channel
- D-channel
- D-echo channel
- dedicated channel
- deep-sound channel
- delta channel
- department communication channel
- digital data channel
- direct channel
- direct control channel
- direct receiving channel
- direct satellite channel
- discrete channel
- discrete-continuous channel
- dispatch communication channel
- double-pole channel
- drop-insertion channel
- duplex communication channel
- E-channel
- electric communication channel
- electric protection channel
- elementary channel
- emergency-radio channel
- engineering channel
- enhanced discrete channel
- even channel
- exchange channel
- fast channel
- fast-acting channel
- fax-modem channel
- feedback channel
- fiber optic communication channel
- firing channel
- fixed-tuned channel
- forcible-borrowed channel
- forward channel
- forward wideband delivery channel
- four-wire channel
- frequency signaling channel
- full-rate traffic channel
- green channel
- group channel
- guard channel
- half-duplex channel
- half-rate traffic channel
- H-channel
- head channel
- health channel
- HF broadband channel
- HF multiplexed channel
- high voltage aerial cable line channel
- highest grade channel
- high-frequency channel
- high-speed signaling channel
- high-voltage aerial line channel
- high-voltage cable line channel
- high-voltage tone line channel
- hydroacoustic channel
- I channel
- ideal channel
- image channel
- in-band orderwire channel
- induced channel
- information bearer channel
- information channel
- infrared channel
- input channel
- input-output channel
- interaction channel
- intercepting-protected channel
- interference channel
- intermodulation channel
- internal phase channel
- internal wire channel
- intrabasin channel
- intradistrict telegraph channel
- intraregional telegraph channel
- ionospheric channel
- isolated bundled phase channel
- jamming channel
- labeled channel
- labeled-statistical channel
- leased channel
- left front channel
- left rear channel
- left stereophonic channel
- line channel
- linear random channel
- line-of-sight channel
- local channel
- logical channel
- long-communication bypass channel
- long-distance channel
- low-frequency channel
- luminance channel
- M channel
- marine radio communication channel
- memory channel
- memoryless channel
- meteor-burst channel
- mobile communication channel
- monochrome channel
- multipath channel
- multiplexing channel
- noiseless channel
- noisy channel
- noncoherent channel
- nonfixed channel
- nonswitched channel
- nonsynchronous channel
- off-hook channel
- one-piece channel
- one-way channel
- open channel
- optimal channel
- optoelectronic channel
- ordinary channel
- outband channel
- output channel
- parallel access channel
- parallel optical channel
- parasitic channel
- peripheral-interface channel
- phase line channel
- phase-phase pitch line channel
- physical channel
- picture channel
- pilot channel
- pipeline control channel
- pitch communication channel
- planar channel
- positioned channel
- primary channel
- protection channel
- Q channel
- quadrature channel
- radio communication channel
- radiotelegraph channel
- radiotelephone channel
- read/write channel
- reception channel
- red channel
- relay channel
- relay protected channel
- return channel
- reverse channel
- reverse control channel
- Ricean channel
- right channel
- right front channel
- right rear channel
- right stereophonic channel
- road safety channel
- road servicing channel
- S channel
- safety channel
- satellite communication channel
- scatter channel
- secondary channel
- selector channel
- send channel
- sensor channel
- separate resonance channel
- series optical channel
- service communication channel
- shared channel
- ship-to-shore channel
- shore-to-ship channel
- side channel
- signal channel
- signaling channel
- single-beam channel
- single-ended channel
- slow channel
- slow-acting channel
- sound broadcasting channel
- sound channel
- space-craft channel
- special cable-line channel
- speech channel
- standard broadcast channel
- subvoice grade channel
- sum channel
- supervisory channel
- switched channel
- symmetrical channel
- synchronous channel
- telecommunication channel
- telemechanic channel
- telemetering channel
- telephone channel
- television channel
- time-derived channel
- toll cable channel
- tone frequency channel
- top channel
- traffic channel
- train dispatch communication channel
- train radio communication line channel
- transfer channel
- transmission channel
- transmission service channel
- transparent channel
- trunk channel
- TV-frequency channel
- TV-observation channel
- two-wire channel
- video channel
- virtual signaling channel
- voice channel
- voice-band channel
- waste channel
- wave channel
- wire communication channel
- wireless channel
- working channel
- write channel

- acoustic imaging device
- active device
- add-in device
- adjusting device
- airplane speaking device
- airplane tape recording device
- alarm device
- all-in-one device
- amplifying device
- analyzing device
- ancillary device
- announcer's device
- answering device
- antenna-feeder device
- antenna-matching device
- antipumping device
- arithmetic device
- arresting device
- attention device
- audible signal device
- automatic program input device
- automatic voice-alert device
- automatic-matching device
- auxiliary call-doubling device
- auxiliary loud-speaking device
- auxiliary radio communication device
- balancing device
- beam-processing device
- buffer device
- burglar-alarm device
- cable device
- calling device
- call-routing device
- central chain data device
- central-control device
- central-intranetwork device
- channel device
- channel-adjusting device
- charge-injection device
- clamping device
- color-imaging device
- combinational device
- combined safety-alarm device
- combined-measuring device
- command-execution device
- command-transit device
- command-transmission device
- compact device
- composite-optoelectronic device
- conditional-access device
- conditioning device
- connecting device
- connection device
- contact-switching device
- control device
- control-calling device
- controlled semiconductor device
- controller device
- counting device
- damping device
- data collection device
- data transmission device
- data-input device
- data-interface device
- data-recording device
- decoding device
- digital device
- digital signal processing device
- discrete control device
- dispatch device
- display device
- doubling device
- dual-tone ringing device
- duplex amplifier bypass device
- duty-reception device
- earthing device
- eavesdropping device
- edge device
- electrodynamical device
- electromagnetic device
- electronic device
- electronic-listening device
- electronic-relay device
- electronic-telegraph device
- electrostatic device
- emergency control device
- error-protecting device
- executive device
- facsimile device
- fast acting device
- fast action device
- fax machine memory device
- ferrite device
- ferrodynamical device
- ferrostatic device
- fiber-optic branching device
- fiber-optic interconnection device
- film optical-sensing device
- filter-matching device
- focusing device
- four-layer device
- four-terminal device
- frequency converting device
- frequency encoding device
- frequency-selective device
- full four-terminal device
- functional device
- gas-discharge device
- groove locating device
- heat device
- IC device
- image-display device
- imaging device
- independent device
- independent-calling device
- independent-telegraph device
- indicating device
- indicator device
- induction device
- in-line device
- input device
- input/output device
- input-isolating device
- input-output device
- input-protector device
- interface device
- interlocking device
- intermediate device
- isotropic device
- laser receiving device
- laser transmitting device
- level control device
- light alarm device
- light-sensitive device
- line HF-device
- linear device
- linear four-terminal device
- line-mounting device
- load device
- locking device
- lockout-signaling device
- logical device
- low-noise start-control device
- low-noise start-controlling device
- low-voltage device
- magnetic device
- magnetic tape sound recording device
- magnetic-wave device
- magnetoelectric device
- magnetoelectronic sparkproof device
- master device
- matching device
- measuring device
- mechanical switching device
- memory device
- message broadcasting device
- metering device
- microelectronic device
- microphone switching device
- mobile speaking device
- modem encryption device
- motor synchronizing device
- multicommunications device
- multifunction device
- multirange measuring device
- n-color device
- network section checkout device
- network synchronizing device
- noncontrolled semiconductor device
- nonlinear four-terminal device
- numbered data requiring and receiving device
- on-off device
- optical-to-optical interface device
- optimal receiving device
- optoelectronic device
- output device
- partial four-terminal device
- partially-controlled semiconductor device
- passive device
- peripheral control device
- peripheral device
- persistent-image device
- phase sensitivity protecting device
- phase shifting device
- photoconductive device
- photoelectric device
- photoemissive device
- photogalvanic device
- photosensitive device
- photothyristor electronic device
- planar device
- polarized device
- power supply device
- primary signal device
- printing device
- protection device
- protective cutout device
- pulse distributing device
- pulse firing device
- pulse semiconductor device
- pulse shortening device
- radio broadcasting device
- radioelectronic device
- real device
- receiving device
- recognition device
- recovering device
- regulating device
- release device
- remote alarm device
- remote control device
- remote network tripping device
- remote positioning device
- remote signaling device
- reserve switching device
- restricted radiation device
- ringing device
- rotary device
- routing device
- safety device
- safety-alarm device
- scanning device
- sealed distribution device
- selective call device
- semiconductor device
- semiconductor switching device
- sensing device
- signal transducing device
- signaling control device
- signaling device
- silicon imaging device
- single chip alarm device
- sizing device
- slave device
- solid optoelectronic device
- spark-protecting device
- spark-safe testing device
- speaking device
- special phototelegraph device
- spectrum transfer device
- start-control device
- start-controlling device
- starter-controlled device
- static protection device
- station HF-device
- stationary station automatic selection device
- stationary-electrical device
- storage device
- strobing device
- subscriber distribution device
- supporting device
- suppression device
- surface acoustic wave device
- surface communication device
- switching device
- sync device
- synthesized-radio device
- tap changing device
- tapping device
- tariff device
- telecontrol device
- teledata transmission device
- telegram format conversion device
- telemetric transmission device
- telephone device
- telephone periphery device
- telering device
- teletex device
- terminal device
- terminal telegraph device
- test device
- thermal regulation device
- three-terminal device
- threshold device
- time-delay device
- timing device
- touch-input device
- transceiving diving device
- transcient telegraph device
- transit device
- transmitter connecting device
- transmitting device
- trunk-encryption device
- two-terminal device
- ultrasonic imaging device
- universal calling device
- universal telegraph device
- videotex device
- voice-control device
- voice-operated gain-adjusting device
- voltage-sensing device
- warning device
- wire speaking device
- wireless speaking device