US3566041A
Expired / Lapsed
US
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Multiple stage switching network
Assignee: International Standard Electric Corp
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Filing: 1968-10-18
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Granted: 1971-02-23
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Expires: 1988-10-18
Abstract
Abstract In a two-stage crossbar switching network where the first stage has overflow, this is provided by overflow links each of which interconnects two switch verticals in different switches. This is by contrast with conventional systems where an overflow link interconnects a horizontal in one switch and a vertical in the other.
Inventors
- 👤 Evert Oskar Ekberg
- 👤 Per Gustaf Jonsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:30
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
205 words
An electrical switching network, for use in an automatic telecommunication exchange, which includes first and second stages of crossbar switches by way of which connections may be set up from inlets of said first stage switches to outlets of said second stage switches, wherein outlets of said first stage switches are each connected to a respective inlet of a second stage switch, so that every inlet to a first stage switch has access to every outlet from a second stage switch, and certain inlets of each first stage switch are connected to inlets of respective other ones of said first stage switches to provide a plurality of inlets usable for overflow connections, which overflow connections may be used when blocking is encountered within the network, wherein each of said first stage switch inlets are directly connected to overflow inlets of a plurality of other first stage switches, so that when blocking condition is encountered, the connection is set up over an overflow path by connecting the inlet to be connected to one of the overflow outlets of the same switch by suitable crossbar operations to a second outlet with access to the wanted outlet of said second stage switch if such usable overflow path exists.
Claim 2
Dependent Claim
205 words
An electrical switching network, for use in an automatic telecommunication exchange, which includes first and second stages of crossbar switches by way of which connections may be set up from inlets of said first stage switches to outlets of said second stage switches, wherein outlets of said first stage switches are each connected to a respective inlet of a second stage switch, so that every inlet to a first stage switch has access to every outlet from a second stage switch, and certain inlets of each first stage switch are connected to inlets of respective other ones of said first stage switches to provide a plurality of inlets usable for overflow connections, which overflow connections may be used when blocking is encountered within the network, wherein each of said first stage switch inlets are directly connected to overflow inlets of a plurality of other first stage switches, so that when blocking condition is encountered, the connection is set up over an overflow path by connecting the inlet to be connected to one of the overflow outlets of the same switch by suitable crossbar operations to a second outlet with access to the wanted outlet of said second stage switch if such usable overflow path exists.
Claim 3
Dependent Claim
46 words
A network as claimed in claim 1, wherein each said first stage switch is formed by two similar small capacity crossbar switches with the outlets interconnected, and wherein each of said two similar crossbar switches has at least one of its inlets usable for overflow connections.
Claim 4
Dependent Claim
168 words
An automatic telephone exchange which comprises a plurality of networks each including a plurality of cascaded stages of crossbar switches with subscriber''s lines connected to the inlet multiples of its first stage switches, and at least one of said networks comprising a plurality of switching units in a first stage of said network having connection to a plurality of switching units in said second stage, a plurality of outlets in each of said first stage switching units for connection of an outlet from each such switching unit to the inlet of a switching unit of said second stage, and wherein each switching unit of said second stage has an input from the output of each switching unit of said first stage, and overflow means in each switching unit of said first stage connected to individual respective overflow inlets of different switching units of said first stage, the one network having its outlets connected to the second stage inlets of said first networks to which said lines are connected.
Claim 5
Dependent Claim
168 words
An automatic telephone exchange which comprises a plurality of networks each including a plurality of cascaded stages of crossbar switches with subscriber''s lines connected to the inlet multiples of its first stage switches, and at least one of said networks comprising a plurality of switching units in a first stage of said network having connection to a plurality of switching units in said second stage, a plurality of outlets in each of said first stage switching units for connection of an outlet from each such switching unit to the inlet of a switching unit of said second stage, and wherein each switching unit of said second stage has an input from the output of each switching unit of said first stage, and overflow means in each switching unit of said first stage connected to individual respective overflow inlets of different switching units of said first stage, the one network having its outlets connected to the second stage inlets of said first networks to which said lines are connected.
Claim 6
Dependent Claim
40 words
An exchange as claimed in claim 3, wherein there are a plurality of trunks, each of which gives access to a different exchange, which trunks are also connected to the inlets of said first stage switches of said first network.
Claim 7
Dependent Claim
83 words
An exchange as claimed in claim 3, wherein there are a plurality of registers, one of which is seized for use for each connection originated by one of said lines or transmitted over one of said trunks for connection to a plurality of register access circuits, and wherein each said register access circuit which has access to more than one of said registers and each register access circuit is included in the connection from a first network outlet to a further network inlet.
Claim 8
Dependent Claim
29 words
An exchange as claimed in claim 3, wherein trunk circuits giving access to remote exchanges are provided, each said trunk circuit being connected to a further switching network inlet.
Claim 9
Dependent Claim
84 words
An exchange as claimed in claim 6, wherein in the case of an outgoing call a trunk circuit which gives access to the wanted exchange is seized and the register connected thereto via one or more switching stages, wherein the wanted number is sent from the register via said one or more switching stages to the trunk circuit, and wherein after said sending has been completed the calling line is connected to tHe trunk circuit and the register and the connections thereto are released.
Claim 10
Dependent Claim
121 words
A multiple stage switching network, wherein each stage comprises a plurality of coordinate switch units with inputs to the switch units of said first stage connected to initiate a path through said network, and the outputs of each switch unit of one stage are connected to the inputs of switch units of said next stage to provide direct access from each switch unit of said first stage to each switch unit of said next stage, and overflow means for connecting each switch unit of said first stage to individual inputs within a plurality of said other switch units of said first stage to provide a plurality of alternate paths from each switch unit of said first stage to the next stage.
Claim 11
Dependent Claim
121 words
A multiple stage switching network, wherein each stage comprises a plurality of coordinate switch units with inputs to the switch units of said first stage connected to initiate a path through said network, and the outputs of each switch unit of one stage are connected to the inputs of switch units of said next stage to provide direct access from each switch unit of said first stage to each switch unit of said next stage, and overflow means for connecting each switch unit of said first stage to individual inputs within a plurality of said other switch units of said first stage to provide a plurality of alternate paths from each switch unit of said first stage to the next stage.
Claim 12
Dependent Claim
60 words
A network as claimed in claim 8, wherein each switch unit comprises two joined crossbar switches with inputs at one coordinate and outputs at the other, the said overflow means comprises cross connections from overflow inputs at said one coordinate of each switch of a switch unit connected to other input coordinates of other switch units of the same stage.
References Cited (Backward Citations)
US1271855A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |