- telefax service
- switch connection
- switch declaration
- switchboard plug
- switched circuit
- switching key
- switching noise
- switching pilot
- switching processor
- switching program
- switching time
- syllabic companding
- syllabic compressor
- syllabic intelligibility
- symbol generator
- symbolic addressing
- symbolic key
- symbolic manipulation
- symbolic operation
- symmetrical reflector
- synchronization line
- synchronizing frame
- synchronous character
- synchronous demodulation
- synthesized music
- synthetic aperture
- system alarm
- system clock
- system console
- system cycle
- system generator
- system unit
- system value
- T-network
- table lookup
- tabulation
- tandem exchange
- tandem links
- telegraph cable
- telegraph charge
- telegraph circuit
- telegraph code
- telegraph error
- telegraph installation
- telegraph key
- telegraph office
- telegraph rate
- telegraph signal
- telegraph traffic
- telegraphic system
- telemarketing
- telematic services
- telematics
- telematics services
- telemetering antenna
- telephone box
- telephone call
- telephone communication
- telephone conference
- telephone connection
- telephone dial
- telephone directory
- telephone extension
- telephone industry
- telephone service
- telephone signaling
- telephone switchboard
- telephone traffic
- telephony band
- telephony carrier
- telepoint
- telerecording equipment
- telescopic antenna
- teleservice
- teletex
- teletext system
- television bandwidth
- television interference
- television line
- television picture
- television standard
- television system
- television tube
- telewriting
- telex
- telex exchange
- telex service
- temperature sounding
- temporarily unavailable
- temporary posts
- temporary storage
- telemetering receiver
- telemetry signal
- telephone bell
- telephone link
- telephone network
- telephone plug
- telephone repeater
- telephone terminal
- telephony