Communications

Telephonic Communications

Electronic (e.g., Tone Generator)

No:6049712

Arrangement system and method relating to telecommunications access and control

No:4513175

Automatic calling systems for accessing communications networks

No:4669110

Call progress tone system

No:4598174

Circuit for detecting keypad conditions in a microprocessor controlled telephone instrument

No:4763355

Combined writing and signaling instrument

No:5781626

Communication device capable of controlling transmission parameters of outputted dtmf signals

No:5583934

Dc level control for an electronic telephone line card

No:4349704

Digital multifrequency signal generator

No:4352958

Electronically-switched multifrequency generator with transducer control

No:4661975

Enhanced call-waiting service

No:4791667

First dialed digit detector and comparator

No:5825871

Information storage device for storing personal identification information

No:6415269

Interactive remote auction bidding system

No:4349705

Lighted telephone dial

No:4103115

Memory tone dialer

No:7023987

Method and apparatus for adapting a phone for use in network voice operations

No:5920623

Method and apparatus for defeating a predictive telemarketing system

No:5541989

Method and apparatus for detecting added keyboard functions

No:4383138

Method and apparatus for processing coded information received through a telephone line during the inter-ringing periods

No:6775364

Method and apparatus for selectively sending a false system information tone on a telephone line

No:5583933

Method and apparatus for the secure communication of data

No:5907597

Method and system for the secure communication of data

No:6137878

Method for outputting user feedback audio messages and telecommunications equipment employing said method

No:5636270

Method of producing signals commonly used with telephones

No:5719921

Methods and apparatus for activating telephone services in response to speech

No:6236724

Methods and apparatus for encoding and decoding data transmitted over telephone lines

No:5832063

Methods and apparatus for performing speaker independent recognition of commands in parallel with speaker dependent recognition of names, words or phrases

No:4549302

Modem with improved escape sequence mechanism to prevent escape in response to random occurrence of escape character in transmitted data

No:4440988

Modem with low part count and improved demodulator

No:4421952

Multi-frequency busy signal synthesizing circuitry

No:3617646

Multifrequency oscillator employing solid-state device switching for frequency selection

No:3361991

Multitone oscillator employing cascaded active r-c filters in feedback loop

No:4126768

Portable automatic number outpulser

No:5539805

Power supply system including ringing voltage reset under low input voltage conditions

No:5208852

Sound generation circuit

No:5781625

System and apparatus for generating within the premises a dial tone for enhanced phone services

No:7110530

System and method for providing universal access to voice response systems

No:5745555

System and method using personal identification numbers and associated prompts for controlling unauthorized use of a security device and unauthorized access to a resource

No:6940974

Systems and methods for generating tones for operating telephones

No:4720855

Telephone apparatus

No:5136632

Telephone service payment system using a sound emitting token

No:4219699

Telephone supervision system using dtmf signals

No:4150254

Telephone system for selecting and reproducing text on a screen

No:5241591

Telephone system having a dial data changeover switch

No:6243460

Telephone with character keypad

No:7466817

Tone generator device for driving light emitting elements

No:7068777

True dtmf dialer

No:5359598

Voice server for digital communication network

No:5165095

Voice telephone dialing

No:4727570

Waveform generators