Subscriber line circuit having an improved offhook supervision c
Subscriber line control apparatus to concurrently detect change
Subscriber line interface circuit having means for combining DC
Subscriber set programming module
Subscriber's line closing circuit
Successive key operating mechanism for telephone dialing
Supervisory control system
Support structure for a keypad
Surge protected electronic switch for telephone voiceband circui
Switch hook status determination in a communication system
Switched network call progress protocol analyzer
System and method for automatically creating new pages in a touc
System and method for connecting pending and preset...
System and method for controlling the dialing order of call reco
System and method for creating a personal directory
System and method for customising call alerts
System and method for deriving sealing current
System and method for detecting an off-hook condition
System and method for detecting customer premises equipment aler
System and method for displaying numbers on a telephone with no