Frequency determining network
Frequency responsive apparatus for reading a meter over a...
Frequency-domain adaptive-filter acoustic echo canceller
Front door telephone system
Front end processor employing data over voice communication...
Full duplex speakerphone for radio and landline telephones
Full electronic two-wire to four-wire conversion circuit
Full featured data access arrangement for use with modems
Fully distributed message storage facilities in a...
Fully-automatic telephone directory assistance apparatus and...
Function for controlling line powered network element
Functionally programmable pcm data analyzer and transmitter...
Future blocking of incoming telephone calls