Telecommunications system, a channel extension protocol, and...
Telephone instrument with built-in modem device, and system...
Telephone system
Telephone system and bell sound detecting method thereof
Telephone system capable of utilizing telephone number informati
Telephone system providing a talking operation after main power
Telephone using service messages for identification signals
Traffic channel allocating method in GSM mobile communication
Transmission channel allocation method and radio apparatus...
Two band 25 channel cordless telephone system