Subscriber terminal for ISDN networks

Superposition of data over voice

Superposition of data over voice

Switch device adapted to interface between an incoming telephone

Switch system for directing call from a calling to a receiving i

Switchable POTS splitter

Switched line modem interface system

Switching control apparatus for a communication terminal having

Switching device for connecting a data transmission system to th

Switching system for application services

Synchronous voice/data message system

System allowing selective connection of various types of externa

System and device for communications

System and method for active filtering in a...

System and method for adding multiple line capabilities to...

System and method for automatically selecting the mode of commun

System and method for communicating electronic messages over a t

System and method for communicating with an out of service...

System and method for communicating with an out of service...

System and method for connecting and interfacing a...