D4 channel bank with multi-mode formatted, performance-monitorin

DAA hook switch

DAC architecture for analog echo cancellation

Dat storage back-up and modem apparatus

Data access arrangement

Data access arrangement

Data access arrangement for detecting the hook status of an...

Data access arrangement having combined remote hang-up/ring dete

Data access arrangement utilizing a serialized digital data...

Data access arrangement utilizing a serialized digital data...

Data access arrangement utilizing a serialized digital data...

Data access arrangement with telephone interface

Data access method for subscriber location information

Data acquisition and error correcting speech recognition system

Data adapter for a radiotelephone

Data and speech transmission device

Data and telephone wiring terminal

Data and voice transmission using composite cables and punch-dow

Data base accessing system

Data calls using both constant bit rate and variable bit...