Call management system
Call notification system, method, computer program and...
Call progress monitor circuitry and method for a...
Caller controlled network-based timed ring suppression
Caller-identification receiving apparatus
Capacitively coupled ring detector with power provided...
Central office filter system and method
Circuit device for controlling the actuated state of an electric
Circuit for evaluating call signals in a telecommunication syste
Communication apparatus for responding to calls to a different a
Communication apparatus having a non-ringing call receiving mode
Communication apparatus having function of generating calling si
Communication system for activating an optical display in a comm
Communication terminal device, holds melody sensing method,...
Communications apparatus, control method therefor and...
Communications device with improved ring signal detection
Computer telephony integrated network
Control circuit for an electrical telephone accessory
Controllable telephone annunciator
Crescendo telephone ringer