Methods and systems for communication from an exterior of a...
Multifunctional intercom system with message...
Noise-free terminal station compatible with existing master stat
On-hold device
Page party system
Patient operator intercom arrangements for magnetic resonance im
Personal handy phone system
Portable through-door intercom
Power line telephone communications system having on hook digita
Privacy mode system and method for home network telephone
Private telephone system using a personal code number to access
Remote answering of doorbell
Sensor system with PT1 measuring device
Single line telephone communication system
Single wire telephone intercommunication system
Single-wire data distribution system and method
System for communicating through partitions
Systems and methods for visitation terminal user identification
Telephone adaptor for telephone sets
Telephone installations