US3878338A
Expired / Lapsed
US
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Time division multiplex telecommunications systems
Assignee: Post Office
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Filing: 1972-11-21
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Granted: 1975-04-15
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Expires: 1992-11-21
Abstract
Abstract A digital switching network employing pulse code modulation (p.c.m.) for conveying information, for use in time division multiplex (t.d.m.) telecommunications systems. The receive portions of n1 p.c.m. systems are applied as inputs to a scanning matrix with each system having been delayed by one bit more than the previous system. The output of the scanning matrix (comprising separate wires on which are read out, at any instant, a different digit from each of the n1 systems) is written into a random access memory that is one which has a unique storage location for each digit of the n, systems). The output of this memory is interconnectible through t.d.m. connection means with a second random access memory, there being read-out (in parallel) from the first memory and written (in parallel) into the second memory at any instant all of the digits of a channel of one of the p.c.m. systems. The output of the second memory is applied to a second scanning matrix the outputs of which are connected to the send portions of n2 p.c.m. systems. At any instant, there are read out from the second memory, on separate wires, a different digit of each of the n2 systems, and on each output of the second scanning matrix there are read-out (in series) the digits of each channel of a respective p.c.m. system. The outputs of the second scanning matrix include delays applied in the reverse order to the delays in the inputs of the first-mentioned scanning matrix.
Inventors
- 👤 John Heskeith Martin Hardy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:28
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/06
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
350 words
A time division multiplex digital switching network comprising, in combination a plurality of pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway and an output highway, a receive conversion unit to which the plurality of input highways are connected, said receive conversion unit comprising a plurality of receive delays, there being for each input highway, a respective unique receive delay which may be zero and to which the input highway is connected, and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of the channels of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means, first storage means to which the plurality of outputs of said series/parallel conversion means are connected, for storing in parallel the serial digits of the channels of the input highways, second storage means having a plurality of inputs and a plurality of outputs, switchable t.d.m. connection means for interconnecting outputs of the first storage means with inputs of the second storage means, a send conversion unit comprising a parallel/series conversion means to which the outputs of the second stage means are connected, and a plurality of send delays, there being, for each output highway, a respective unique send delay, which may be zero and to which an outpUt of said parallel/series conversion means is connected, for converting parallel digital information on the outputs of said second storage means into serial form on any one of a plurality of outputs of said send delays, each output highway being connected to the output of the respective send delay, control means for operating said connection means to establish a desired connection between a channel of an input highway and a channel of an output highway by reading-out in parallel from the first storage means the digits of the said input channel at a time allocated by said connection means and writing-in said read-out in parallel into the second storage means at the said allocated time.
Claim 2
Dependent Claim
350 words
A time division multiplex digital switching network comprising, in combination a plurality of pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway and an output highway, a receive conversion unit to which the plurality of input highways are connected, said receive conversion unit comprising a plurality of receive delays, there being for each input highway, a respective unique receive delay which may be zero and to which the input highway is connected, and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of the channels of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means, first storage means to which the plurality of outputs of said series/parallel conversion means are connected, for storing in parallel the serial digits of the channels of the input highways, second storage means having a plurality of inputs and a plurality of outputs, switchable t.d.m. connection means for interconnecting outputs of the first storage means with inputs of the second storage means, a send conversion unit comprising a parallel/series conversion means to which the outputs of the second stage means are connected, and a plurality of send delays, there being, for each output highway, a respective unique send delay, which may be zero and to which an outpUt of said parallel/series conversion means is connected, for converting parallel digital information on the outputs of said second storage means into serial form on any one of a plurality of outputs of said send delays, each output highway being connected to the output of the respective send delay, control means for operating said connection means to establish a desired connection between a channel of an input highway and a channel of an output highway by reading-out in parallel from the first storage means the digits of the said input channel at a time allocated by said connection means and writing-in said read-out in parallel into the second storage means at the said allocated time.
Claim 3
Dependent Claim
37 words
A network as claimed in claim 1, having at least one pair of first storage means the outputs of which are common and at least one pair of second storage means the inputs of which are common.
Claim 4
Dependent Claim
51 words
A network as claimed in claim 1, including for each first storage means, an address generator operable to generate a respective address for each input channel of said first storage means and to apply the address to the first storage means to write-in, in parallel, the serial digits of the channel.
Claim 5
Dependent Claim
52 words
A network as claimed in claim 1, including, for each second storage means, an address generator operable to generate a respective address for each output channel of said second storage means and to apply the address to the second storage means to read out, in series, the parallel-stored digits of the channel.
Claim 6
Dependent Claim
45 words
A network as claimed in claim 1, in which the control means includes a common control connected to receive information from a channel of an input highway relating to a desired connection to be established between that channel and a channel of an output highway.
Claim 7
Dependent Claim
76 words
A network as claimed in claim 5, in which the control means includes a call set-up unit operable to test for and allocate in said t.d.m. connection means a free channel necessary to establish the said desired connection, and then to apply addresses to the first and second storage means to read-out from the first storage means the digits of said channel of an input highway and to write-in said read-out into the second storage means.
Claim 8
Dependent Claim
46 words
A network as claimed in claim 5, in which the control means includes, for the first and second storage means, at least one respective information address memory, in bothway communication with the common control, for storing the address of each operational location of the storage means.
Claim 9
Dependent Claim
45 words
A network as claimed in claim 5, in which the control means includes, for the first storage means, at least one state of channel memory, in bothway communication with the common control, for storing the state of each input channel of said t.d.m. connection means.
Claim 10
Dependent Claim
45 words
A network as claimed in claim 5, in which the control means includes, for the second storage means, at least one state of channel memory, in bothway communication with the common control, for storing the state of each output channel of said t.d.m. connection means.
Claim 11
Dependent Claim
76 words
A network as claimed in claim 5 in which the t.d.m. connection means is a cross-point matrix and the control means includes, for the second storage means, at least one second address memory, in both way communication with the common control, for receiving information relating to the interconnections required between outputs of the first storage means and inputs of the second storage means to establish a desired connection between an input channel and an output channel.
Claim 12
Dependent Claim
60 words
A network as claimed in claim 1, in which the receive delays comprise delays of 0 to (n1-1) bits to which the input highways of p.c.m. systems 0 to (n1-1) respectively are connected, and the series/parallel conversion means has n1 outputs on which are read out in parallel, at any instant, a different digit from each of the n1 systems.
Claim 13
Dependent Claim
46 words
A network as claimed in claim 11, in which the first storage means has a unIque storage location for each of the mp digits of the n1 systems (m being the number of channels in each system and p being the number of digits per channel).
Claim 14
Dependent Claim
59 words
A network as claimed in claim 1, in which the parallel/series conversion means has n2 inputs into which are written in parallel, at any instant, a different digit from each of n2 p.c.m. systems, and the send delays comprise delays of (n2-1) to 0 bits to which the output highways of p.c.m. systems 0 to (n2-1) respectively are connected.
Claim 15
Dependent Claim
46 words
A network as claimed in claim 13, in which the second storage means has a unique storage location for each of the mp digits of the n2 systems (m being the number of channels in each system and p being the number of digits per channel).
Claim 16
Dependent Claim
51 words
A network as claimed in claim 1, in which said series/parallel conversion means comprises a single scanning matrix the outputs of which are a plurality of separate wires, and a scan generator for reading out at any instant, on said separate wires, a different digit from each of said p.c.m. systems.
Claim 17
Dependent Claim
32 words
A network as claimed in claim 1, in which said series/parallel conversion means comprises a plurality of shift registers, and multiplexor means to which the outputs of the shift registers are connected.
Claim 18
Dependent Claim
27 words
A network as claimed in claim 1, in which said first storage means comprises, for each output of said series/parallel conversion means, a respective parallel digit store.
Claim 19
Dependent Claim
32 words
A network as claimed in claim 1, in which said parallel/series conversion means comprises demultiplexor means and a plurality of shift registers to which the outputs of the demultiplexor means are connected.
Claim 20
Dependent Claim
125 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and a receive conversion unit interconnected between said highways, said unit comprising, for each input highway a respective unique receive delay which may be zero and to which the input highway is connected, and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of each channel of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means.
Claim 21
Dependent Claim
125 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and a receive conversion unit interconnected between said highways, said unit comprising, for each input highway a respective unique receive delay which may be zero and to which the input highway is connected, and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of each channel of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means.
Claim 22
Dependent Claim
131 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and a send conversion unit interconnected between said highways, said unit comprising a parallel/series conversion means having a plurality of inputs for receiving in parallel form the digits of the channels of said input highways and, for each output highway, a respective unique send delay which may be zero and to which the output highway is connected, for converting parallel digital information on the inputs of said parallel/series conversion means into serial form on one of said output highways.
Claim 23
Dependent Claim
131 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication systems each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and a send conversion unit interconnected between said highways, said unit comprising a parallel/series conversion means having a plurality of inputs for receiving in parallel form the digits of the channels of said input highways and, for each output highway, a respective unique send delay which may be zero and to which the output highway is connected, for converting parallel digital information on the inputs of said parallel/series conversion means into serial form on one of said output highways.
Claim 24
Dependent Claim
201 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication system each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and receive and send conversion units interconnected between said highways, said receive conversion unit comprising, for each input highway, A respective, unique receive delay which may be zero and to which the input highway is connected and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of each channel of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means, and said send conversion unit comprising a parallel/series conversion means having a plurality of inputs for receiving in parallel form, the digits of the channels of said input highways, and for each output highway, a respective unique send delay which may be zero and to which the output highway is connected, for converting parallel digital information on the inputs of said parallel/series conversion means into serial form on one of said output highways.
Claim 25
Dependent Claim
201 words
A time division multiplex communication system comprising in combination a plurality of incoming pulse code modulated communication system each comprising a plurality of channels, with a plurality of serial digits per channel, each system having an input highway, a plurality of outgoing pulse code modulated communication systems each having an output highway, and receive and send conversion units interconnected between said highways, said receive conversion unit comprising, for each input highway, A respective, unique receive delay which may be zero and to which the input highway is connected and a series/parallel conversion means to which the outputs of said receive delays are connected, for converting the serial digits of each channel of said input highways into parallel form on a plurality of outputs of said series/parallel conversion means, and said send conversion unit comprising a parallel/series conversion means having a plurality of inputs for receiving in parallel form, the digits of the channels of said input highways, and for each output highway, a respective unique send delay which may be zero and to which the output highway is connected, for converting parallel digital information on the inputs of said parallel/series conversion means into serial form on one of said output highways.
Claim 26
Dependent Claim
60 words
A system as claimed in claim 21, in which the receive delays comprise delays of 0 to (n1-1) bits to which the input highways of p.c.m. systems 0 to (n1-1) respectively are connected, and the series/parallel conversion means has n1 outputs on which are read out in parallel, at any instant, a different digit from each of the n1 systems.
Claim 27
Dependent Claim
59 words
A system as claimed in claim 21, in which the parallel/series conversion means has n2 inputs into which are written in parallel, at any instant, a different digit from each of n2 p.c.m. systems, and the send delays comprise delays of (n2-1) to 0 bits to which the output highways of p.c.m. systems 0 to (n2-1) respectively are connected.
Claim 28
Dependent Claim
51 words
A system as claimed in claim 21, in which said series/parallel conversion means comprises a single scanning matrix, the outputs of which are a plurality of separate wires, and a scan generator for reading out at any instant, on said separate wires, a different digit from each of said p.c.m. systems.
Claim 29
Dependent Claim
32 words
A system as claimed in claim 21, in which said series/parallel conversion means comprises a plurality of shift registers, and multiplexor means to which the outputs of the shift registers are connected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |