Abstract: Modular multiplex/demultiplex apparatus suitable for use in a telephone communication system for processing data transmitted between local and remote telephone subscribers. The multiplex/demultiplex apparatus comprises a plurality of module units which may be interconnected together, for example, in one or more groups, for processing and routing data originating with local subscriber equipment to selected ones of a plurality of trunk group modules and associated modems for transmission to remote subscriber equipment, and for processing and routing data received by the trunk group modules and modems from remote subscriber equipment. Each module unit includes a shift register having a plurality of demultiplex input lines for receiving demultiplexed data thereon and a series input for receiving multiplexed data. Data present on the demultiplex input lines or at the series input is shifted to an output of the shift register.

Abstract: Modular multiplex/demultiplex apparatus suitable for use in a telephone communication system for processing data transmitted between local and remote telephone subscribers. The multiplex/demultiplex apparatus comprises a plurality of module units which may be interconnected together, for example, in one or more groups, for processing and routing data originating with local subscriber equipment to selected ones of a plurality of trunk group modules and associated modems for transmission to remote subscriber equipment, and for processing and routing data received by the trunk group modules and modems from remote subscriber equipment. Each module unit includes a shift register for receiving and shifting therealong a multiplexed signal received from a selected one of the trunk group modules. A counter counts the bits shifted along the shift register and when the shift register is full it produces an output count signal.

Abstract: An essential user bypass circuit for use in switch units of a telephone switching system. Telephone subscribers at each switch unit are able to communicate with each other and with subscribers at other switch units via associated subscriber apparatus and trunk group lines interconnecting the switch units. All call processing operations, including the formation of "from-to" address signals for connecting subscribers with each other and with trunk group lines, are normally controlled by a processor unit (containing dual processors) at each switch unit.

Abstract: Digital signal generator for producing digital signalling codes employed in a digital telephone communication system including several tone generators for providing presynthesized digital tone signals which are convertible to audible tones. Permutable digital codewords are produced by a codeword generator. Some of the tone signals and codewords are combined by FSK and switching circuitry. Tone signals, codeword signals, and combination signals are stored in storage registers and read out by a multiplexer to provide a continuous TDM bit stream of 60 channels of digital signalling codes.

Abstract: A TDM switching network for a communication system having 17 input transmission lines for carrying TDM digital signals in 64 input channels on each input line and having 15 output transmission lines for carrying TDM digital signals in 64 output channels on each output line. The TDM switching network establishes connections between selected input and output channels in accordance with address instructions having A and B address segments each designating a particular channel of a particular transmission line. The switching network includes 15 switching matrices (plus a spare). Each matrix is connected to all 17 of the input transmission lines and to a different one of the output transmission lines. Each switching matrix includes a data memory which can store a data bit for each channel of each transmission line. Each matrix also includes an address memory which can store an address segment for each channel of the associated output transmission line at a corresponding storage location.