Scrambling system for an audio frequency signal
Scrambling system for audio frequency signals
Scrambling/descrambling method using a memory for storing...
Secret signalling system
Secret speech equipment
Secure communication apparatus and method
Secure communication system
Secure communication system
Secure communication system
Secure communication system for multiple remote units
Secure computer interface
Secure messaging system overlay for a selective call...
Secure mobile radio telephony
Secure open-air communication system utilizing multi-channel...
Secure sca broadcasting system including subscriber actuated...
Secure system using continuously-changing features of a body...
Secure telecommunications
Secure trunked communications system
Secure voice transmission
Security remote control method and system