Redcom Laboratories, Inc.

Other

Jerome S Caplan

Charles J Breidenstein

Klaus Gueldenpfennig

Bruce G Littlefield

James W Delmege

Elaine M Kazimir

Christine Navarro

Paul A Buchiere

Robert R Laman

A TDM (Time Division Multiplexed) telephony switching system which provides expanded switching capacity without change in the physical form factor of the system or of the design of the circuits which provide TDM multiplexed digital signals (the port and service circuits). Additional ports and service circuits are provided in the same number of time slots per frame as existed before system expansion thereby providing additional ports and/or service circuits which can be interconnected without significantly affecting the cost of the system. Expansion is achieved by multiplexing the digital signals and transmitting them at a higher rate on existing send highways of the system. The time slot interchange is expanded by providing a memory with additional locations for each group of additional circuits. The signals are demultiplexed and switched in the time slot interchange and transmitted on receive highways (additional receive highways being provided for the additional groups of circuits) at the rate at which the existing port and service circuits are designed to operate. The expanded system is, therefore, compatible since the highway signals as seen from the circuits being switched are unchanged. Also, the existing design of the shelves, and the back plane interconnecting board thereof, is compatible with the expanded system.

Expanding switching capability of a time division communication system

A time division multiplex switching system converts call formats and signalling protocols so that calls can be interchanged between circuits originating in different networks thereby providing a gateway for telephone transmissions originating from sources (e.g., foreign countries) having differences in transmission (signal attenuation characteristics and companding laws) and signalling and numbering plans or protocols. This switching system is characterized by a processor which is programmed to identify the circuits requiring interconnection and to process signalling messages in accordance with the signalling systems and formats used in the circuits, while translating the signalling messages into common, protocol independent signaling messages which are used for establishing time division multiplex connections in a time slot interchange which is connected to the circuits via PCM highways and for exchanging signalling information (e.g., as to seizure, detection and release) between the circuits; the signalling messages also containing information for conversion of PCM data messages which are switched in the time slot interchange thereby reconciling differences in transmission, such as the companding law used for PCM encoding and decoding and the attenuation (pad value) of the call data in the circuits. The circuits may, for example, be incoming and outgoing trunks.

Time division multiplex switching system for interconnecting telephone

An interface system for port circuits of a distributed PCM telephony switching system enables different complements of port circuits (different numbers of line circuits or of trunk circuits or of digital circuits which handle multiple party conferences) to be connected into the PCM telephony switching system so as to meet different user requirements. The interface system handles the PCM data signals carrying voice (analog) and digital information. The interface system also handles control signals generated in the telephony processor and transfers the data between the port circuits and the highways of the PCM switching system in sequential time slots. The timing of the time slots, the allocation of the time slots to different data is selectable by manually, configurable, programmable, switching devices which set up codes and connections corresponding to the complement of port circuits which are to be interfaced with the PCM telephony switching system. These switching devices are implemented by programmable headers having conductive elements which may be left intact or severed. The same interface circuitry, but with different connections intact and severed in their programmable headers, is used to establish the timing and allocate time slots in accordance with the configuration of port circuits selected by the user of the telephony system, thereby opening the architecture of the telephony system to different port circuit arrangements while isolating the telephony system from the port circuits for safety and security of operation of the telephony system.

Flexible interface system for interfacing different complements of port

A communications switching system is controlled as a peripheral device to a general purpose digital host computer or other host device. The switching system has a plurality of ports for telephone lines and/or trunks and makes connections to the ports. The host computer is programmable at high level to obtain customized switching applications. The switching processes are carried out in the switching system under control of high level commands. The commands are formatted to identify the command functions and the ports at which the switching and control actions are to be carried out. These ports may be provided by separate modular switching units, each having processors for carrying out the switching functions at the designated ports and for distributing the commands in accordance with the command format to the designated port regardless of which of the modular switching units has the port. Responses as to the execution of the switching events are also conveyed to the host computer in a format which designates the response function and the port at which the function occurred. The switching units may be equipped with asynchronous serial data links for connecting one or more host computers or devices to the modular switching peripheral units.

Communications switching system with modular switching communications

High density component mounting back panel for electronic equipment

Synchronous operation of any number of digital switching units of a TDM system is maintained by interconnecting the switching units to a timing signal highway which distributes timing signals generated by sources of such signals in any one of the units. The units are connected successively in a chain by timing signal distribution control lines. Validity signals are generated and transmitted by circuits in each unit along the lines so as to provide for transmission of timing signals generated in the first switching unit on to the timing signal highway and switch over of the timing signal generating function to successive ones of the units when the timing signal generation in preceding units becomes faulty.

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Henrietta, NY, United States of America

Jerome S Caplan