Returning ringing signals through the tip amplifier of...
RF connected message recording device and method for a telephone
Ring boost circuit to extend ringing range of telephone SLICs
Ring relay control unit for foreign exchange station
Ring voltage generation circuit and method for generating a...
Ring voltage termination by means of a spare fuse
Ring-back powered telephone with nonvolatile memory structure
Ring-detect interface circuitry and method for a...
Ring-signal generation in a SLIC
Ringing controller
Ringing signal control circuit for an enhanced subscriber line i
Sealed terminating device
Sealing current generator for a telephone circuit
Security cover for telephone line installation backboard and met
Security latch for network interface devices and plastic...
Security mechanism for snap latch devices
Self configuring telephone headset amplifier
Self-adaptive echo canceller capable of keeping a degree of canc
Self-balancing hybrid using digitally programmable attenuator fo
Self-calibration procedure in physical layer transceiver for...