Credit card collect call system and method
Credit card telephone station
Credit transaction arrangements
Credit/calling card pay telephone method and system employing te
Data communication circuit and method using telephone system
Debit calling label
Detection of telephone number spoofing
Dial assembly terminalgard
Directed call return service
Dispenser with vandal resistant coin validator runway
Domestic origination to international termination country...
Dynamic escrow type detection system
Dynamic microphone handset and amplifier unit
Electrical wallbox for telephone devices
Encryption of telephone calling card codes
Enhanced access to telecommunications network
Face plate for coin operated telephone boxes
Face plate with ad frames for coin operated telephone boxes
False call protecting apparatus for use with telephone exchange
Fraud prevention in an electronic coin telephone set