auxiliary switching point

auxiliary boiler

auxiliary boiler feeder

auxiliary close-up lens

auxiliary contact

auxiliary contact accessory

auxiliary contact deck

auxiliary cut

auxiliary electrode

auxiliary engine

auxiliary engine sailing ship

auxiliary feedwater system

auxiliary jet

auxiliary machinery

auxiliary memory

auxiliary mirror

auxiliary motor

auxiliary parachute

auxiliary power unit

auxiliary rotor

auxiliary service position

auxiliary servo control

auxiliary shoe

auxiliary storage

auxiliary store

auxiliary switch

auxiliary switching point

auxiliary switching unit

auxiliary track

auxiliary transformer

auxiliary valve

auxiliary vessel

- accumulator unit
- actuating unit
- addressing unit
- analog processing unit
- analytic unit
- answerback unit
- answering unit
- antitheft unit
- astronomical unit
- attached unit
- audio response unit
- auto setup unit
- automatic calling unit
- automatic control unit
- automatic network unit
- automatic-dialing unit
- auxiliary memory unit
- auxiliary servicing unit
- bad unit
- balancing unit
- base unit
- basic transmission unit
- bistable unit
- break-contact unit
- built-in heat protecting unit
- burglar-alarm unit
- calibration unit
- calling devices unit
- calling unit
- camera select unit
- camera-channel unit
- camera-control unit
- capacitor unit
- channel service unit
- charging unit
- clocking unit
- command network unit
- command protocol data unit
- communication control unit
- converter unit
- crosstalk unit
- data interface unit
- data transit unit
- data-handling unit
- dc control unit
- decoupling unit
- delay unit
- device control unit
- dial-backup unit
- dialing unit
- digital processing unit
- electronic control unit
- electronic relay unit
- electrostatic units
- exchange-line unit
- exchange-supply unit
- expedited-data unit
- fast-operating unit
- fast-operation unit
- feeding unit
- file-storage unit
- filter unit
- flyaway unit
- frequency conversion unit
- frequency lock-in unit
- frequency selection unit
- Gaussian units
- generator unit
- heat-control unit
- incoming local unit
- incoming toll unit
- incoming-line unit
- independent supply unit
- independent synchronizing unit
- indicator unit
- information unit
- input unit
- integrator unit
- internal unit
- internetworking unit
- junction line unit
- key-telephone unit
- lighting load monitoring unit
- line-connection unit
- lobe-attaching unit
- local unit
- locomotive radio components supply unit
- lone-signal unit
- loudness unit
- magnetic-tape unit
- main control unit
- main fax unit
- main memory unit
- mains synchronizing unit
- matching unit
- media interface unit
- medium attachment unit
- memory unit
- message recording unit
- microprocessor unit
- mine communication supply unit
- modular unit
- motor amplifier unit
- multipath unit
- multiprocessor unit
- multisection switching unit
- network terminating unit
- N-unit
- office interface unit
- off-line unit
- on-door speakers unit
- operational unit
- outgoing line unit
- output unit
- pan/tilt unit
- peripheral unit
- phase-shifting unit
- phasing unit
- power supply unit
- power unit
- printing unit
- processing unit
- program unit
- programming unit
- quad-on-line unit
- quartz crystal unit
- quick-disconnect control unit
- radio frequency unit
- radio station unit
- rectifier unit
- reference generator unit
- regeneration unit
- registrating unit
- relay testing unit
- relay unit
- remote control unit
- remote display unit
- remote subscriber unit
- replacement unit
- request unit
- resistor unit
- retransmission unit
- RF unit
- selective-gain unit
- self-contained unit
- sensing unit
- shared unit
- shared-control unit
- signal processing unit
- six-wire switching unit
- smooth-closing unit
- sound repetitor protection unit
- spark protecting unit
- stabilizator unit
- still picture unit
- storage unit
- studio devices unit
- sub unit
- subscriber's unit
- subundercarrier unit
- supply unit
- switch point operative communication unit
- switching unit
- synchronization signal unit
- system memory unit
- system unit
- tape unit
- telecine unit
- telecontrol unit
- telephone-control unit
- telephone-modulator unit
- teleprompter unit
- temperature-sending unit
- terminal retransmissions unit
- terminal unit
- terrestrial telemechanics unit
- three-wire switching unit
- time-base unit
- traffic unit
- transfer unit
- transit communication unit
- transmissive unit
- transmitting antenna unit
- tributary unit
- two-section switching unit
- undercarrier unit
- underground telemechanics unit
- unit of power
- vibrator unit
- video request unit
- video-out unit
- voice message control unit
- voice recognition unit
- voicememory unit
- writing unit

- adapter circuit
- adjustment circuit
- alive circuit
- announcing circuit
- anode circuit
- antisidetone circuit
- asynchronous circuit
- automatic reset-data circuit
- automatic ringdown circuit
- automatic start circuit
- auxiliary circuit
- balanced circuit
- balanced-wire circuit
- balancing circuit
- band-switching circuit
- basic circuit
- black-level restoring circuit
- black-level stretch circuit
- bootstrap circuit
- branch circuit
- branched circuit
- bridge antisidetone circuit
- building-out circuit
- built-up circuit
- Buttler circuit
- bypass circuit
- cached circuit
- call circuit
- capacitor-coupled circuit
- capacitor-switched circuit
- capacitor-switching circuit
- central-battery circuit
- chain-type connection circuit
- character generator large-scale integration circuit
- charge-coupled device circuit
- check parity circuit
- checkout circuit
- chrominance matrix circuit
- chrominance separation circuit
- chrominance takeoff circuit
- clamp-on circuit
- closed circuit
- coarse phasing circuit
- coaxial circuit
- coincidence circuit
- color-balance circuit
- color-indexing circuit
- color-purity circuit
- combinational-circuit circuit
- combined-supply circuit
- common-base circuit
- common-battery circuit
- common-collector circuit
- common-drain circuit
- common-emitter circuit
- common-gate circuit
- common-source circuit
- common-user circuit
- communication circuit
- comparing circuit
- compensating antisidetone circuit
- complemental metal-oxide-semiconductor circuit
- composite circuit
- conductor-bundled static wire circuit
- conference circuit
- connecting circuit
- constant-closed circuit
- contactor-relay circuit
- continental circuit
- convergence circuit
- cord circuit
- correcting circuit
- Costas circuit
- counter-coupling circuit
- counting-down circuit
- coupled circuit
- cross-bus matrix circuit
- crossed-waveguide circuit
- cue circuit
- cutoff circuit
- Darlingtone circuit
- data circuit
- data-transmission circuit
- dc restoration circuit
- decoder circuit
- delay circuit
- demodulation circuit
- dial-up circuit
- diamond circuit
- differencing circuit
- differential-frequency circuit
- digital circuit
- digital-excitation circuit
- digital-leased circuit
- diode-clamping circuit
- diode-clipping circuit
- diode-stabilitron circuit
- direct international circuit
- direct-connection circuit
- direct-transit international circuit
- direct-wire circuit
- double half-wave circuit
- double-ended cord circuit
- double-loop circuit
- dual circuit
- earth circuit
- earthed circuit
- echo-absorption circuit
- edge derivation circuit
- electric circuit
- electronic circuit
- elementary circuit
- encoding circuit
- energized circuit
- engineering circuit
- equivalent circuit
- error-subtracting circuit
- external circuit
- fallback circuit
- feed circuit
- feedback circuit
- fiber-optic circuit
- fire-control circuit
- fixed-virtual circuit
- flexible circuit
- flexible-stage circuit
- flywheel circuit
- forked circuit
- four-wire circuit
- frame scanning circuit
- frequency-changing circuit
- frequency-protection circuit
- full-accessible circuit
- full-period allocated circuit
- functional-switching circuit
- gallium-arsenide integrated circuit
- gating circuit
- generating circuit
- Gilbert circuit
- Grets circuit
- grid circuit
- ground-return circuit
- grouping circuit
- half-bridge circuit
- half-wave circuit
- hardened circuit
- head circuit
- HF-correction circuit
- holding circuit
- horizontal deflection circuit
- hybrid circuit
- hypothetical reference circuit
- idle lighting limiting circuit
- inclined adjustment circuit
- incoming circuit
- independent circuit
- inductive circuit
- input circuit
- input-by-output matrix circuit
- inquiry circuit
- integrated circuit
- integrating circuit
- interchange circuit
- interface-integrated circuit
- interferenced circuit
- interferencing circuit
- international leased circuit
- interstage coupling circuit
- invertor circuit
- ISDN echo cancellation circuit
- isochronic circuit
- Jiakoletto circuit
- junction circuit
- Karp circuit
- keep-alive circuit
- key section power circuit
- killer circuit
- ladder circuit
- lamp circuit
- large-scale integration circuit
- latched circuit
- LCR circuit
- lead changeover circuit
- LF-correction circuit
- line circuit
- linear circuit
- link circuit
- live circuit
- local circuit
- lock-in circuit
- locking circuit
- lock-out circuit
- long circuit
- long-distance circuit
- longitudinal circuit
- loop circuit
- lossless resonant circuit
- L-shaped circuit
- magnetic convergence circuit
- main supply circuit
- make circuit
- Marx circuit
- match circuit
- matching circuit
- matrix circuit
- message circuit
- microelectronic circuit
- microphone supply circuit
- multidrop circuit
- multijunctor circuit
- multiloop circuit
- multipoint circuit
- muting circuit
- neodymium magnetic circuit
- neutral circuit
- neutralization circuit
- neutralizing circuit
- noise-rejecting circuit
- noise-suicide circuit
- nonlinear circuit
- NOT circuit
- on-call circuit
- open circuit
- optoelectronic integrated circuit
- OR circuit
- order wire circuits
- OR-ELSE circuit
- oscillating circuit
- oscillation circuit
- output circuit
- output voltage tracking circuit
- packaged circuit
- paging circuit
- parallel circuit
- partially accessible circuit
- peaking circuit
- periodic closed circuit
- phantom circuit
- phase comparating circuit
- phase compensating circuit
- phase-shift circuit
- phase-substitution circuit
- physical circuit
- pilot circuit
- pilot-make-busy circuit
- planar circuit
- point-to-point circuit
- polling circuit
- polyphase circuit
- power circuit
- power-supply circuit
- precision phasing circuit
- primary circuit
- printed circuit
- private leased circuit
- protection circuit
- pulse-phase control circuit
- push-to-talk circuit
- push-to-type circuit
- quenching circuit
- quiet-tuning circuit
- radial supply circuit
- radio circuit
- RC circuit
- reactance control circuit
- reading circuit
- rectification circuit
- reference circuit
- rejecting circuit
- relay cutout circuit
- remote control circuit
- remote-ring circuit
- repeat circuit
- reset circuit
- resonance circuit
- resonant circuit
- reverse circuit
- reverse diode circuit
- ring circuit
- ringing circuit
- sample-and-hold circuit
- scaling circuit
- Scott circuit
- secondary circuit
- section substitution circuit
- selecting circuit
- selective circuit
- self-locked circuit
- series circuit
- series-oscillating circuit
- series-parallel circuit
- series-peaking circuit
- series-tuned circuit
- shaping circuit
- shaved single frequency circuit
- short circuit
- shunt circuit
- shunting circuit
- shunt-peaking circuit
- side circuit
- signal circuit
- signal processing circuit
- signal recovery circuit
- single-current circuit
- single-ended push-pull circuit
- single-frequency resonance circuit
- single-phase bridge circuit
- single-phase circuit
- snap-acting circuit
- solving circuit
- sound-program circuit
- spark-safe circuit
- speech circuit
- speed regulating circuit
- squaring circuit
- stabilizer circuit
- stable circuit
- stage circuit
- stage control circuit
- standard cable circuit
- standard circuit
- standby circuit
- stenode circuit
- storage large-scale integration circuit
- storage locking circuit
- straightforward circuit
- strap magnetic circuit
- strip-line circuit
- super large scale integration circuit
- superimposed circuit
- superposed circuit
- supply circuit
- sweep circuit
- switched circuit
- switching circuit
- symistor control circuit
- synchronous circuit
- tail circuit
- talk-back circuit
- tandem data circuit
- tank circuit
- tapped magnetic circuit
- tapped stage circuit
- telecommunication circuit
- telecommunication-protection circuit
- telegraph circuit
- telegraph grade circuit
- telegraph signal generating circuit
- telephone circuit
- telephone signal generating circuit
- telesignaling receiving circuit
- telesignaling sending circuit
- television circuit
- terminal circuit
- test circuit
- testing circuit
- third circuit
- three-loop circuit
- three-phase input circuit
- three-wire circuit
- through circuit
- thyristor control circuit
- time protection circuit
- time-delay circuit
- time-interval protection circuit
- time-setting circuit
- timing circuit
- toll circuit
- touch sensing circuit
- touch tone dial circuit
- transformer substitution circuit
- transformer-coupled circuit
- transistor clipping circuit
- transistor collector circuit
- transistor control circuit
- transistor protection circuit
- tributary circuit
- triode clamp circuit
- trunk circuit
- T-shaped circuit
- tuned circuit
- twelve-pulse circuit
- two-frequency resonance circuit
- two-loop circuit
- two-wire-ground circuit
- uniform circuit
- unstable circuit
- untapped circuit
- untapped magnetic circuit
- U-shaped circuit
- variometer controlling circuit
- video circuit
- virtual circuit
- voice circuit
- voltage multiplying circuit
- voltage sensor circuit
- watching output circuit
- wideband circuit
- wire circuit
- wired circuit

- 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