Communications

Telephonic Communications

Signal Receiver (e.g., Tone Decoder)

No:7272233

Acoustic shock prevention

No:6173054

Adaptive call progress tone detection system

No:5321745

Adaptive efficient single/dual tone decoder apparatus and method for identifying call-progression signals

No:6691073

Adaptive state space signal separation, discrimination and recovery

No:4403298

Adaptive techniques for automatic frequency determination and measurement

No:7068781

Alarm of a telecommunications terminal connected to a lan

No:5265157

Answer supervision and service selection

No:5311589

Apparatus and method for audible signaling tone recognition

No:7054435

Apparatus and method for determining a minimal time bound for performing tone detection

No:5535271

Apparatus and method for dual tone multifrequency signal detection

No:5319703

Apparatus and method for identifying speech and call-progression signals

No:7236585

Apparatus and method for noise immunity during signal detection

No:6580254

Apparatus and method for providing span power to communication equipment at a customer premise

No:6218930

Apparatus and method for remotely powering access equipment over a 10/100 switched ethernet network

No:5325427

Apparatus and robust method for detecting tones

No:6091803

Architecture for robust voice cti

No:4489438

Audio response system

No:5724420

Automatic call distribution with answer machine detection apparatus and method

No:4878236

Automatic emergency locator system and method

No:4935958

Busy/no-answer call completion equipment

No:4809321

Busy/no-answer call completion equipment

No:4995076

Call progress capability for a switched channel data service unit

No:5483593

Call progress decoder for multiple cadenced tones on telephone lines

No:5311588

Call progress detection circuitry and method

No:4686699

Call progress monitor for a computer telephone interface

No:4528664

Call progress signal monitor and method for telephone systems

No:5519764

Circuit and method for detecting error causing tones in a voice messaging system

No:4922528

Circuitry for recognizing two-tone compound signals in telephone installations

No:5007000

Classification of audio signals on a telephone line

No:6269160

Communications device including an improved cpe alerting signal (cas) detection system

No:4878196

Communications management system

No:6097796

Communications terminal apparatus capable of detecting wide range of busy tones through telephone line

No:4856055

Controllable telephone annunciator

No:6480589

Cpe alert signal detector and caller identification detector using peak detection

No:6393124

Cpe alert signal tone detector

No:6587559

Cross-frame dual tone multifrequency detector

No:5428662

Detecting make-break clicks on a telephone line

No:6415139

Detection circuit of tone signal

No:6950511

Detection of both voice and tones using goertzel filters

No:5333191

Detection of multifrequency tone signals

No:5481589

Detection of tdd signals in an automated telephone system

No:4363100

Detection of tones in sampled signals

No:5563942

Digital call progress tone detection method with programmable digital call progress tone detector

No:4534041

Digital circuit for determining the envelope frequency of pcm encoded call progress tones in a telephone system

No:4570235

Digital receiver of multifrequency signals with frequency recognition device

No:4689760

Digital tone decoder and method of decoding tones using linear prediction coding

No:5815568

Disabling tone detector for network echo canceller

No:5528663

Dtmf detection for voice processing equipment

No:5392348

Dtmf detection having sample rate decimation and adaptive tone detection

No:5809133

Dtmf detector system and method which performs frequency domain energy calculations with improved performance