Transient signal elimination circuit for telecommunications appl
Transmission system with improved tone detection
Transmission system with improved tone detection
Transmission system with improved tone detection
Tray for automatic dial telephones
True alert indication
True DTMF dialer
Tune master internet protocol device
Two way telephone communication system
Two-way voice communication methods and apparatus
Two-wire telecommunications line detection arrangements
Two-wire telecommunications line detection arrangements
Unified method and apparatus to simplify telephone area code dia
Unified method and apparatus to simplify telephone area code...
Unified method and apparatus to simplify telephone area code...
Unique ringing on a prime telephone
Use of an echo canceller for the detection of CAS signals
User programmable station set bass and treble control
Vandal-resistant push-button actuator
Variable color display telephone