Preliminary communication identification
Presence based DTMF signaling enablement of voice...
Printer-option system for exchanging data between a terminal and
Priority line switching system
Private automatic business exchange
Private branch exchange
Private branch exchange
Process for data communications and a data communications system
Processor-assisted communication system using tone-generating te
Programmable data access arrangement having combined command sig
Programmable universal modem system and method for using the sam
Public switched telephone network access to public data network
Public telephone network
Public telephone network including a distributed imaging system
Public telephone network including a distributed imaging system
Public terminal for access to a computer network
Public terminal receptacle
Public terminal receptacle
Push button phone capable of sending to the telephone line alpha
Push/pull modem interface circuit