ABSTRACT:   A distributed control digital switching system is described in which a plurality of subscriber lines and trunks are provided with a switched access to various processing functions shared over a plurality of time shared multiplexed lines. Each processor of a first group of processors is dedicated to a group of terminals such as subscriber lines or trunks, and communicate with processors in a second group to provide pooled processing functions to one or more of said groups of terminals through a digital switching matrix. Processors in the first group perform a first set of processing functions, such as path set up and processors of the second group perform a second set of processing functions, such as call control. A multistage switching network provides a modularly expandable digital group switch, the operation of which is controlled externally from the terminals to which it is connected, and provides rate synchronous, phase (bit) asynchronous interconnection among the terminals which are interfaced and switched. Each processor of the first group is time shared over a security block of lines or trunks providing hardware interface therebetween while each processor of the second group provides pooled functions for a plurality of security blocks of lines and trunks. All data, speech and control signals are coupled over common transmission paths.

U.S. REFERENCES:

31 patents reference this one

Patent No. Inventor Issued Title 3348210 * Ochsner 10 /1967   3781818 Pardoe et al. 12 /1973 DATA BLOCK MULTIPLEXING SYSTEM 3787818 Arnold et al. 1 /1974 MULT-PROCESSOR DATA PROCESSING SYSTEM 3856993 Closs et al. 12 /1974 TIME DIVISION MULTIPLEX EXCHANGE 3934232 Curley et al. 1 /1976 Interprocessor communication apparatus for a data processing system 3943494 Holmes, Jr. et al. 3 /1976 Distributed execution processor 3959775 Valassis et al. 5 /1976 Multiprocessing system implemented with microprocessors 3969701 Hemdal 7 /1976 Function block oriented SPC system 3970994 Jenny 7 /1976 Communication switching system 3978455 Valassis et al. 8 /1976 I/O structure for microprocessor implemented systems 3984819 Anderson 10 /1976 Data processing interconnection techniques 3997896 Cassarino, Jr. et al. 12 /1976 Data processing system providing split bus cycle operation 4023145 Duerdoth et al. 5 /1977 Time division multiplex signal processor 4025725 Euler 5 /1977 Telecommunication switching network having a multistage reversed trunking scheme and switching on a four wire basis 4030072 Bjornsson 6 /1977 Computer system operation and control 4031512 Faber 6 /1977 Communications network for general purpose data communications in a heterogeneous environment 4045617 Schlichte 8 /1977 Telecommunication switching network having a multistage reversed trunking arrangement 4074072 Christensen et al. 2 /1978 Multiprocessor control of a partitioned switching network by control communication through the network 4113988 Mukaemachi et al. 9 /1978 Speech path packaging unit including controller containing shift register 4146749 Pepping et al. 3 /1979 Telecommunications network having multi-function spare network block   * some details unavailable EXEMPLARY CLAIM(s): Show all 22 claims We claim: 1. A distributed control digital communication system for selectively interconnecting a plurality of groups of terminals thru a digital switching network having an access switching stage and one or more other switching stages, comprising: a first group of data processing means for providing a first set of pooled processing functions for said groups of terminals, each of said processing means being associated with one of said groups of terminals; a second group of data processing means for providing a second set of pooled processing functions for one or more of said groups of terminals such that said second processing functions are provided independently of the processing functions provided by said first group of processing means; and digital switching network means coupled to said first and second groups of processing means by one or more multiplexed transmission paths over which data and at least path selection control signals are transmitted in frames containing a plurality of channels of said data, such that said path selection control signals establish communication over said multiplexed transmission paths thru said digital switching network means between said first and second groups of data processing means with said path selection control signals preceding said data on said multiplexed transmission paths in the same channels and selectively interconnect said terminals over transmission paths thru said switching network in channels designated by said path selection control signals. 15. A distributed control digital communication system comprising a plurality of terminal units for interfacing a plurality of PCM communication terminals carrying digitized speech in frames containing a plurality of channels of said digitized speech to a common communications path upon which said frames and in-channel path selection control signals are multiplexed, and comprising: means for deriving at least digital path selection control signals for each PCM terminal interfaced thereto; a digital switching network coupled to said communications path for bit asynchronously interconnecting said PCM terminals through paths established thru said switching network in response to said in-channel path selection control signals, and; means at each of said terminal units for selectively multiplexing said digitized speech and said in-channel path selection control signals on said common communications path such that said digital path selection control signals precede said digitized speech in channels designated by said path selection control signals on said common communications path. RELATED U.S. APPLICATIONS: none FOREIGN APPLICATION PRIORITY DATA: none FOREIGN REFERENCES: Document No. Country Date Intl. Class 2502516 Federal Republic of Germany 7 /1975   1214106 United Kingdom 12 /1970   OTHER REFERENCES: "Study of a Rural Digital End Office," by Michael J. Kelly, Telephone Engineer & Management, Dec. 1, 1977. PRIMARY/ASSISTANT EXAMINERS: Brown; Thomas W.; ADDED TO DATABASE: Aug. 22, 1996