Communications

Telephonic Communications

For Calling Station (e.g., Status Or Progress Tones)

No:5265157

Answer supervision and service selection

No:5206900

Automated attendant

No:4995076

Call progress capability for a switched channel data service unit

No:7050564

Call progress tone generation in a communication system

No:7203304

Call progress tone generation in a communication system

No:7421071

Call progress tone generation in a communication system

No:3917910

Circuitry for providing call override in a pbx system in accordance with a supplied class of service

No:3956595

Circuitry for providing executive ringback in a pbx system

No:5557658

Communications marketing system

No:5428670

Communications marketing system

No:4775975

Dial tone detection arrangement with a detection notification feature

No:5457690

Dtmf signaling on four-wire switched 56 kbps lines

No:3436486

Error detection system

No:6404863

First party signalling for call waiting calling number identification (cwcid) system

No:4455455

Internodal conference call administrator

No:5014300

Method and apparatus for accessing a facsimile store and forward network

No:4811382

Method and apparatus for applying messages in a telecommunications network

No:5134651

Method and apparatus for providing answer supervision and an autonomous pay telephone incorporating the same

No:5363435

Method and apparatus for seizing a trunk circuit in a telecommunications private branch exchange

No:5583933

Method and apparatus for the secure communication of data

No:5862212

Method and structure for detecting a customer premises equipment alerting signal

No:5793858

Method for improving call completion rates in telephony

No:7072644

Method for providing a caller-based ringback tone sound in case of a non-subscribed called

No:5937039

Method for sending out absent messages from isdn exchange system

No:5790287

Optical communication system with improved maintenance capabilities

No:5436964

Programmable call progress tones for a switching system

No:5233641

Radio telephone equipment having a sounding device for generating alert tone indicative of response of called subscriber

No:4696031

Signal detection and discrimination using waveform peak factor

No:5781625

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

No:4410765

Telephone call routing and charging system

No:5321740

Telephone marketing system

No:7013393

Universal intelligent card for secure access to system functions