Call management system
Call notification system, method, computer program and...
Call progress decoder for multiple cadenced tones on telephone l
Call progress monitor circuitry and method for a...
Call signal detecting device
Call transmitter for the input of control commands,...
Call-routing device
Called party response detecting apparatus
Caller controlled network-based timed ring suppression
Caller identification interface using line reversal detection
Caller-identification receiving apparatus
Canonical telephone numbers
Capacitively coupled ring detector with power provided...
Card system
Card-like device having a microprocessor and speaker for communi
CAS tone disguising method and apparatus
Cellular car telephone dialing controller
Central office filter system and method
Circuit and method for automatic memory dialing
Circuit and method for automatically cutting off a speech path a