LandOfFree - US Patents - Listing for Telephonic communications

Telephonic communications – Echo cancellation or suppression – Residual echo cancellation

Differential line bridge for scaleable near-end speech...

Telephonic communications – Subscriber line or transmission line interface

Differential longitudinal amplifier for a subscriber line interf

Telephonic communications – Subscriber line or transmission line interface – Power supply

Differential output stage for electronic equipment providing...

Telephonic communications – Substation or terminal circuitry – Sidetone control or hybrid circuit

Differential receive booster amplifier for telephone instruments

Telephonic communications – With usage measurement – Call charge metering or monitoring

Differentiated threshold value behavior in prepaid services

Telephonic communications – Call signal generating

Differing frequency sine wave generation from a look-up table

Telephonic communications – Centralized switching system – Switching controlled in response to called station...

Digit parsing for a flexible dial plan capability in a telecommu

Telephonic communications – Substation or terminal circuitry – Hold circuit

Digital access arrangement circuitry and method for...

Telephonic communications – Subscriber line or transmission line interface

Digital access arrangement circuitry and method having a...

Telephonic communications – Subscriber line or transmission line interface

Digital access arrangement circuitry and method having...

Telephonic communications – Subscriber line or transmission line interface

Digital access arrangement circuitry and method having...

Telephonic communications – Substation or terminal circuitry – For loudspeaking terminal

Digital adaptive filter and acoustic echo canceller using...

Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Testing of subscriber loop or terminal

Digital and synthesized speech alarm system

Telephonic communications – Special services – Anonymous party

Digital audio interface in a mobile telephone

Telephonic communications – Multi-line or key substation system with selective switching...

Digital button telephone system and extension terminal for...

Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Including fault responsive disconnection of tested component

Digital bypass for telephone system

Telephonic communications – Supervisory or control line signaling – Signalling integrity protection

Digital call progress tone detection method with programmable di

Telephonic communications – Audio message storage – retrieval – or synthesis

Digital Cellular Overlay Network (DCON)

Telephonic communications – Audio message storage – retrieval – or synthesis

Digital cellular switching system with means for securing uninte