Abstract: A modular, reconfigurable, intelligent signal multiplexer for telecommunications purposes includes a rack or shelf adapted to support a plurality of printed circuit cards. The cards include feature cards and line cards, and at least one central controller card. All of the cards includes backplane connectors to connect to customer premises equipment and to telecommunications lines, and midplane connectors to interconnect all of the circuit cards for data exchange under program control. Each feature card contains an embedded microprocessor with associated embedded operating system, as well as RAM memory and flash RAM. The signal multiplexer processes digital inputs from a wide range of user equipment for transmission over digital facilities, including T1 and T3 lines. The system employs an Advanced Intelligent Multiplexer Network software package to perform network configuration and SNMP to obtain performance reports, statistics collection and alarm monitoring.

Abstract: Apparatus for dropping and inserting digital data in a time division multiplexed, serial data stream. A communications link is divided into two spans with an electrical switch connecting the two spans. Data is used to derive channel-timing information defining the time divisions or strobes of each of the multiplexed channels. The strobe pulses are used to toggle the switch so that local transmit-and-receive channels may be inserted and dropped in accord with the channel strobe pulses. The same channel strobe pulses used for transmitting local data are used for receiving data from the multiplexed bit stream. In the absence of channel strobe pulses, the switch connects the two links.

Abstract: A system for multiplexing either a single or multiple information channels adjacent to the video spectrum on a TV microwave or cable by frequency modulating a high frequency subcarrier at wide deviation with one or composite information signals, translating the modulated subcarrier to a frequency adjacent to and above the video spectrum, and then bridging it into the video circuit at a level 20 dB or more below the peak video signal of the video spectrum. The system recovers the transmitted subcarrier from the video spectrum, synthesizes the subcarrier frequencies exclusive of most of the video interference in a limited bandwidth, and then detects the modulation of the synthesized subcarrier frequency.