Multiple fault tolerant digital switching system for an automatic telephone system

Claim 2

In a ditial switching arrangement for an automatic telephone system, a plurality of lines, a plurality of line switch means, each of which line switch means includes input means connected to a different one of said lines, and each of which line switch means is operative to concentrate signals input from its lines for use in the system, at least one switching network comprised of at least a first and second subnetwork, at least a first time division link connecting the signal output of each of a plurality of said line switch means to said first subnetwork, and a second time division link connecting the signal output of the same plurality of line switch means to said second network, a plurality of highways, a plurality of multiplexer means in each of said subnetworks for selectively connecting said first and second time division links to said highways, and time-space-time switching network means comprising a plurality of switch groups for each of said subnetworks, different ones of said switch groups for a subnetwork having a different one of said highways which is connected to a different one of said multiplexer means for establishing connections between its associated highways.

Claim 3

A digital switching arrangement as set forth in claim 1 in which each of said line switch means is also operative to expand signals input to said line switch means by said links from the system.

Claim 4

A digital switching arrangement as set forth in claim 2 in which at least certain of said line switch means includes per line A/D conversion means and D/A conversion means.

Claim 5

A digital switching arrangement as set forth in claim 1 in which each of said means for connecting said links to said highways comprises a plurality of multiplexing means, and which includes at least one intra network link connected between each of a plurality of multiplexing means in one of said subnetworks and each of a plurality of said multiplexing means in the other of said subnetworks, whereby overflow traffic which occurs in said subnetwork can be processed by said multiplexing means in said other subnetwork.

Claim 6

In a digital switching arrangement as set foRth in claim 1 in which said time-space-time switching network includes a plurality of switch groups, each of which switch groups is connected to a different one of said highways, and each switch group has a plurality of switch means including means for controlling the selective operation of said switch means, and means interconnecting the switch means in said switch groups.

Claim 7

In a digital switching arrangement for an automatic telephone system, the improvement comprising a plurality of lines, a switching network which includes a first plurality and a second plurality of multiplexing means, a plurality of superhighways, each of which is connected to a different one of said multiplexing means, line switch means for said lines, at least one time division link comprising T1 lines for connecting the outputs of said line switch means to an input for each of a plurality of said multiplexing means, and a second time division link comprising T1 lines for connecting the signal output of the same line switch means to said second plurality of multiplexing means, and time space time network including a plurality of modular switch groups, each of which switch groups incudes a different one of said superhighways, and means in each switch group for selectively effecting connection to the other ones of said switch groups.

Claim 8

In a digital switching arrangement for an automatic telephone system, the improvement comprising a plurality of lines, a switching network which includes a first plurality and a second plurality of multiplexing means, a plurality of superhighways, each of which is connected to a different one of said multiplexing means, line switch means for said lines, at least one time division link comprising T1 lines for connecting the outputs of said line switch means to an input for each of a plurality of said multiplexing means, and a second time division link comprising T1 lines for connecting the signal output of the same line switch means to said second plurality of multiplexing means, and time space time network including a plurality of modular switch groups, each of which switch groups incudes a different one of said superhighways, and means in each switch group for selectively effecting connection to the other ones of said switch groups.

Claim 9

A system as set forth in claim 6 in which each of said time division links has a plurality of channel groups, and each of said multiplexing means connected to said time division links is operative to process a different one of said channel groups on said time division links to the one of said highways which is connected thereto.

Claim 10

A digital switching arrangement as set forth in claim 6 in which each of said line switch means comprises a discrete line circuit for each of said lines, each of which line circuits has a first and second output, each line switch means including control means for connecting said first and second outputs for each line circuit to said first and second time division lines respectively, whereby each line is provided access to at least one of said subnetworks in the event of failure of one of said time division links.

Claim 11

A digital switching arrangement as set forth in claim 6 which includes further peripheral equipment, and digital links only for connecting said peripheral equipment to said multiplexing means.

Claim 12

A digital system as set forth in claim 6 which includes a channel bank for converting analog signals to digital signals, means for connecting analog incoming trunks to said channel bank, and at least one digital link connecting the output of said channel bank to at least one input of each of said plurality of multiplexing means.

Claim 13

In a digital switching arrangement for an automatic telephone system, a plurality of lines, line switch means connected to said lines, a switching network including at least a first and a second subnetwork, each of which subnetworks includes multiplexing means, each multiplexing means including a plurality of multiplexer-demultiplexer circuits, a plurality of highways, each of which highways is connected to a different one of said multiplexer-demultiplexer circuit, a first time division link connected between said line switches and each of said plurality of multiplexer-demultiplexer circuits in said first subnetwork, a second time division link connected between said line switches and each of said plurality of multiplexer-demultiplexer circuits in said second subnetwork, each of said time division links having a plurality of groups of channels, and each of said multiplexer-demultiplexer circuits being operative to process a different one of said groups of channels on its associated time division link to its interconnected highway.

Claim 14

In a digital switching arrangement for an automatic telephone system, a plurality of lines, line switch means connected to said lines, a switching network including at least a first and a second subnetwork, each of which subnetworks includes multiplexing means, each multiplexing means including a plurality of multiplexer-demultiplexer circuits, a plurality of highways, each of which highways is connected to a different one of said multiplexer-demultiplexer circuit, a first time division link connected between said line switches and each of said plurality of multiplexer-demultiplexer circuits in said first subnetwork, a second time division link connected between said line switches and each of said plurality of multiplexer-demultiplexer circuits in said second subnetwork, each of said time division links having a plurality of groups of channels, and each of said multiplexer-demultiplexer circuits being operative to process a different one of said groups of channels on its associated time division link to its interconnected highway.

Claim 15

A system as set forth in claim 11 in which said first and second time division links each has twenty-four channels, and in which said plurality of multiplexing means in each of said subnetworks comprises four discrete multiplexer-demultiplexer ciRcuits, said four circuits being associated with forty time division links and in which each group of channels on each time division link comprises six channels.

Claim 16

A digital switching arrangement as set forth in claim 11 which includes a common control means, and in which at least one of the time slots on each of said highways is used to transmit control signals from a common control means.

Claim 17

In a digital switching arrangement for an automatic telephone system, a plurality of lines, a plurality of line switch means, each of which line switch means includes input means connected to a different one of said lines, and each of which line switch means is operative to concentrate signals from its lines for use in the system, at least one switching network comprised of at least a first and second subnetwork, at least a first time division link connecting the signal output of each of a plurality of said line switch means to said first subnetwork, and a second time division link connecting the signal output of the same plurality of line switch means to said second subnetwork, and at least one intra network link connected between said first and second subnetwork for use in routing the overflow traffic of one of said subnetworks to the other of said subnetworks.

Claim 18

In a digital switching arrangement for an automatic telephone system, a plurality of lines, a plurality of line switch means, each of which line switch means includes input means connected to a different one of said lines, and each of which line switch means is operative to concentrate signals from its lines for use in the system, at least one switching network comprised of at least a first and second subnetwork, at least a first time division link connecting the signal output of each of a plurality of said line switch means to said first subnetwork, and a second time division link connecting the signal output of the same plurality of line switch means to said second subnetwork, and at least one intra network link connected between said first and second subnetwork for use in routing the overflow traffic of one of said subnetworks to the other of said subnetworks.

Claim 19

A digital switching arrangement as set forth in claim 14 in which each of said line switch means is also operative to expand signals input to said line switch by digital links from the system.

Claim 20

A digital switching arrangement as set forth in claim 15 in which certain of said line switch means include A/D conversion means and D/A conversion means.

Claim 21

In a digital switching arrangement for an automatic telephone system, a plurality of lines, a switching network which includes a first plurality of multiplexing means, a plurality of highways, each of which is connected to a different one of said multiplexing means, line switch means for said lines, at least one time division link for connecting said line switch means to each of a plurality of said multiplexing means, said time division link having a plurality of channel groups, each of said multiplexing means connected to said time division link being operative to process a different group of said channels on said time division link to the one of said highways which is connected thereto, a time space time network including a plurality of switch groups, a plurality of circuit paths, each of which is common to said plurality of switch groups, each switch group having a first path connected to one of said common circuit paths, said first path for the different ones of the switch groups being connected to a correspondingly different one of said common circuit paths, a second path in each switch group, a group of switch means in each switch group, each of which switch means of a group is operative to connect said second path for its switch group to a correspondingly different one of said common circuit paths, and controller means in each switch group for selectively closing the different switch means in its associated group of switch means.

Claim 22

In a digital switching arrangement for an automatic telephone system, a plurality of lines, a switching network which includes a first plurality of multiplexing means, a plurality of highways, each of which is connected to a different one of said multiplexing means, line switch means for said lines, at least one time division link for connecting said line switch means to each of a plurality of said multiplexing means, said time division link having a plurality of channel groups, each of said multiplexing means connected to said time division link being operative to process a different group of said channels on said time division link to the one of said highways which is connected thereto, a time space time network including a plurality of switch groups, a plurality of circuit paths, each of which is common to said plurality of switch groups, each switch group having a first path connected to one of said common circuit paths, said first path for the different ones of the switch groups being connected to a correspondingly different one of said common circuit paths, a second path in each switch group, a group of switch means in each switch group, each of which switch means of a group is operative to connect said second path for its switch group to a correspondingly different one of said common circuit paths, and controller means in each switch group for selectively closing the different switch means in its associated group of switch means.

Claim 23

A digital switching arrangement as set forth in claim 17 in which said plurality of circuit paths extend as a series of parallel vertical columns through each one of said switch groups, and said second path in each switch group extends horizontally across said vertical columns, and in which the switch means for a switch group are located at the points of intersection of the second path for said switch group with said vertical columns.

Claim 24

A digital switching arrangement as set forth in claim 17 which includes at least one common control means for selectively providing control signals for said controller means in each of said switch groups, and digital link means for connecting said control signals from said common control means to a group of said first plurality of multiplexing means for selective processing over said highways to said controller means.

Claim 25

A switching arrangement as set forth in claim 19 in which At least one time slot on each highway is assigned for use in the transmission input by the processor to one of said switch groups to others of said switch groups.

Claim 26

A switching arrangement as set forth in claim 19 in which said common control includes at least a processor circuit and a memory circuit means, and in which said digital link means includes a first path for connecting said processor circuit to said multiplexing means, and a second path for connecting said memory circuit means to said multiplexing means, whereby said memory and said processor connect with each other via said switching network.

Claim 27

A digital switching arrangement as set forth in claim 19 in which said digital link means comprises at least a first and a second time division link connecting the output of said common control means to at least one of said first plurality of multiplexing means.

Claim 28

A digital switching arrangement as set forth in claim 17 which includes means connecting said first path in each switch group to its associated highway, and in which each switch group includes output means for connecting said second path therein over its associated highway to the connected one of said multiplexing means, and in which closure of only one switch means in one switch group connects the first path in the switch group which is connected to the common circuit path selected by the closed switch means to the second path in said one switch group.

Claim 29

A system as set forth in claim 17 which includes a second plurality of multiplexing means, and common control means including a first and a second processor means, a first time division link for connecting the output of said first processor means to each one of a group of said first plurality of said multiplexing means, and a second time division link for connected the output of said first processor means to each one of a group of said second plurality of said multiplexing means, a third time division link for connecting the output of said second processor means to each one of a group of said first plurality of multiplexing means, and a fourth time division link for connecting the output of said second processor means to each one of a group of said second plurality of multiplexing means.

Claim 30

A digital switching arrangement as set forth in claim 17 in which each of said highways comprises a first and a second path, and in which said multiplexing means comprises a multiplexing circuit for multiplexing the signals input over said time division link to said one path of said highway and the switch group connected thereto, and a demultiplexer circuit for demultiplexing the data transmitted by said one switch group over said second path of said highway for transmission over said time division link.

Claim 31

A digital switching arrangement as set forth in claim 17 in which each of said highways includes a first and a second highway path and said multiplexing means comprises a multiplexer circuit and a demultiplexer circuit, and in which said controller means in each switch group comprises an input time slot interchanger having an input connected over said first highway path for the switch group to the associated multiplexer circuit, and an output circuit for said input time slot interexchange connected to a predetermined one of said vertical columns, the output circuits for the different ones of said input line slot interchangers being connected to correspondingly different ones of said vertical columns, an output time slot interchanger in each switch group having its input connected to the switch means controlled by its switch group and its output connected over said second highway path to the demultiplexing circuit for the switch group, a control circuit in each switch group connected to said input and output time slot interchangers, and operating means connected to said controller circuit for selectively operating the switch means for its switch group.

Claim 32

A digital switch arrangement as set forth in claim 26 in which said operating means comPrises a crosspoint control memory having its input connected to the output of said controller circuit, and a crosspoint address decoder having its input connected to the output of said crosspoint control memory, and an output circuit connected to selectively control the closure of the switch means of its switch group.

Claim 33

A digital switching system as set forth in claim 27 in which each of said controller circuits comprises a microprocessor having an input connected between said input and output time slot interchangers and said crosspoint control memories.

Claim 34

A multiple fault tolerant digital switching system comprising a set of peripherals, said set of peripherals being comprised of input/output facilities including digital trunks, analog trunks, and subscriber lines and being further comprised of control facilities including control processors and related common control equipment, digital links which serve as time division multiplex lines for carrying pulse code modulated data, one or more of said links being interconnected to each peripheral in said set of peripherals, and a switching network for switching pulse code modulated data among said digital links, said digital links being the exclusive interface between said switching network and said peripheral equipment including said digital trunks and said analog trunks.

Claim 35

A multiple fault tolerant digital switching system comprising a set of peripherals, said set of peripherals being comprised of input/output facilities including digital trunks, analog trunks, and subscriber lines and being further comprised of control facilities including control processors and related common control equipment, digital links which serve as time division multiplex lines for carrying pulse code modulated data, one or more of said links being interconnected to each peripheral in said set of peripherals, and a switching network for switching pulse code modulated data among said digital links, said digital links being the exclusive interface between said switching network and said peripheral equipment including said digital trunks and said analog trunks.