| Patent No. | Patent Title: |
| 5479505 | Telephone network enclosure containing protected termination devi... |
| 5452352 | Automatic dialing system |
| 5442696 | Method and apparatus for detecting control signals |
| 5442698 | Ringing generator for telephones |
| 5436968 | Digital data-dependent ac impedance termination of telephone line |
| 5430796 | Auxiliary attenuator arrangement for use in voice-switched speake... |
| 5428681 | Apparatus and method for reducing the risk of undesirable paramet... |
| 5422948 | Subscriber line interface for improving the frequency characteris... |
| 5422929 | Telephone line repeater and method of testing same |
| 5420921 | Method for the detection of a disable tone signal of an echo canc... |
| 5420918 | Telephone apparatus for invalidating incoming call signals during... |
| 5418849 | Procedure and device for adaptive digital cancellation of the ech... |
| 5416837 | Telephone network interface enclosure |
| 5408332 | Focusing apparatus for video camera or the like |
| 5402483 | Digital telephone system with terminals connected to a digital ex... |
| 5371789 | Multi-channel echo cancellation with adaptive filters having sele... |
| 5363436 | Remotely programmable, vandal-resistant voice communications unit |
| 5361300 | Balancing resistor and thermistor network for telephone circuits,... |
| 5347576 | Line interface unit retrofit circuit |
| 5333192 | Line interface circuit |
| 5333194 | Autoequalizing bidirectional-to-unidirectional hybrid network |
| 5333195 | Telephone network speech signal enhancement |
| 5329588 | Telecommunication line circuit |
| 5323457 | Circuit for suppressing white noise in received voice |
| 5315644 | Telephone interface circuit |
| 5313519 | Protected telephone network interface device |
| 5311588 | Call progress detection circuitry and method |
| 5307404 | Signal detecting device |
| 5305377 | Apparatus for providing an ISDN to analog interface |
| 5289538 | Circuit arrangement for signal and information conversion between... |
| 5287404 | Telephone subscriber line voltage change detection |
| 5285495 | Push-button telephone dialing device with telephone hold function... |
| 5283827 | Digital line card for interfacing a remotely located digital tele... |
| 5280521 | Portable telephone system |
| 5280524 | Bone conductive ear microphone and method |
| 5274701 | Telephone alerter |
| 5271059 | Method and configuration for forming a line termination of a tele... |
| 5271060 | Circuitry for interfacing telecommunications equipment to a ... |
| 5267309 | Telephone line unit having programmable read-only memory |
| 5255316 | Hands-free telephone apparatus |