US3673335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching of time division multiplex lines and analog trunks through telephone central offices
Assignee: AT&T Inc
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Filing: 1970-08-24
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Granted: 1972-06-27
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Expires: 1990-08-24
Abstract
Abstract A telephone switching office is disclosed wherein connections may be established between conventional analog trunks and time division multiplex lines. A plurality of digital trunks are employed equal in number to the number of incoming and outgoing time slot channels to be switched through the office. Digital trunks associated with incoming channels are provided with shift registers for storing the bit patterns carrying the information for a respective time slot. This information is outpulsed from the shift registers under control of readout pulses derived from a trunk time slot switch which is set by common control to deliver readout pulses in a time sequence that is appropriate to the selected time slot in the outgoing TDM line to which a crossoffice connection is desired. In addition, conversion junctor circuits are provided having encoders and decoders which are selectively gated to deliver the digital information to the appropriate time slot of the TDM line involved in the connection by signals derived from a junctor time slot switch whose operation is dictated by common control Advantageously, both the trunk time slot link switch and the junctor time slot link switches are of the crossbar type.
Inventors
- 👤 Amos Edward Joel Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:47
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
245 words
An arrangement for switching communications channels carried by time division multiplex lines through a space division switching network of a switching office having a common control unit, comprising: a trunk circuit for each of said communications channels carried by said time division multiplex lines, each said trunk circuit having an appearance in said switching network, means for storing in each said trunk circuit associated with an incoming one of said time division multiplex lines the contents of a respective incoming one of said communications channels, a time slot link switch connectable under control of said common control unit to said storing means of each said trunk circuit associated with an incoming one of said time division multiplex lines, time slot distributor means for supplying to said link switch a respective sequence of storing means readout pulses corresponding to each channel of an outgoing one of said time division multiplex lines, means including said common control unit for selecting and establishing a cross-office connection from said storing means respective to said incoming one of said communications channels to one of said trunk circuits associated with an idle communications channel carried by an outgoing one of said time division multiplex lines, and means including said control unit and said time slot link switch for connecting a sequence of said pulses corresponding to said selected idle outgoing communications channel to said storing means of said incoming trunk circuit to read out the contents thereof into said cross-office connection.
Claim 2
Dependent Claim
245 words
An arrangement for switching communications channels carried by time division multiplex lines through a space division switching network of a switching office having a common control unit, comprising: a trunk circuit for each of said communications channels carried by said time division multiplex lines, each said trunk circuit having an appearance in said switching network, means for storing in each said trunk circuit associated with an incoming one of said time division multiplex lines the contents of a respective incoming one of said communications channels, a time slot link switch connectable under control of said common control unit to said storing means of each said trunk circuit associated with an incoming one of said time division multiplex lines, time slot distributor means for supplying to said link switch a respective sequence of storing means readout pulses corresponding to each channel of an outgoing one of said time division multiplex lines, means including said common control unit for selecting and establishing a cross-office connection from said storing means respective to said incoming one of said communications channels to one of said trunk circuits associated with an idle communications channel carried by an outgoing one of said time division multiplex lines, and means including said control unit and said time slot link switch for connecting a sequence of said pulses corresponding to said selected idle outgoing communications channel to said storing means of said incoming trunk circuit to read out the contents thereof into said cross-office connection.
Claim 3
Dependent Claim
65 words
An arrangement according to claim 1 wherein said common control unit includes a register-sender connectable to any of said trunk circuits associated with an incoming one of said time division multiplex lines and wherein each of said last-mentioned trunk circuits includes second register means and means for inserting into said second register means a signal indicating the connection of said trunk circuit to said register-sender.
Claim 4
Dependent Claim
43 words
An arrangement according to claim 2 further comprising gating means connected to said second register means and means for controlling said gating means to transfer the contents of said second register means to an outgoing channel of said incoming time division multiplex line.
Claim 5
Dependent Claim
57 words
An arrangement according to claim 2 wherein said storing means of said incoming trunk circuit includes a primary and a secondary shift register, connection path means for transferring a portion of the contents of said primary shift register to said register-sender and connection path means for transferring the contents of said register-sender to said secondary shift register.
Claim 6
Dependent Claim
78 words
An arrangement according to claim 2 wherein said storing means of said incoming trunk circuit includes a primary and a secondary shift register, connection path means for transferring a portion of the contents of said primary shift register to said register-sender and connection path means for inserting subsequent to the establishment of said cross-office connection, a signal to indicate the calling condition of said selected one of said trunk circuits associated with said outgoing time division multiplex line.
Claim 7
Dependent Claim
23 words
An arrangement according to claim 4 further comprising connection path means for transferring the contents of said register-sender to said secondary shift register.
Claim 8
Dependent Claim
237 words
An arrangement for establishing communications connections among channels carried by time division multiplex lines and analog trunks comprising a switching office having a space division switching network operated by a common control unit to establish cross-office connections, a plurality of analog trunks appearing in said network, a digital trunk circuit appearing in said network for each of said communications channels carried by said time division multiplex lines, a plurality of junction circuits including conversion junctor circuits having encoder means for translating analog signals into pulse code modulation signals and decoder means for translating pulse code modulation signals into analog signals, gating means connected to said decoder and encoder means, a time slot link switch connected to said gating means, said link switch being operable to apply to said gating means sequences of pulses corresponding to any channel of one of said digital trunks, and means including said common control unit for establishing a cross-office connection between one of said analog and one of said digital trunks including one of said conversion junctor circuits, said common control unit operating said time slot link switch connected to said gating means to govern the admission and release of said analog and digital signals into and out of said decoder and encoder means, respectively, in step with said sequences of pulses corresponding to the channel of said time division multiplex line associated with said digital trunk involved in said cross-office connection.
Claim 9
Dependent Claim
237 words
An arrangement for establishing communications connections among channels carried by time division multiplex lines and analog trunks comprising a switching office having a space division switching network operated by a common control unit to establish cross-office connections, a plurality of analog trunks appearing in said network, a digital trunk circuit appearing in said network for each of said communications channels carried by said time division multiplex lines, a plurality of junction circuits including conversion junctor circuits having encoder means for translating analog signals into pulse code modulation signals and decoder means for translating pulse code modulation signals into analog signals, gating means connected to said decoder and encoder means, a time slot link switch connected to said gating means, said link switch being operable to apply to said gating means sequences of pulses corresponding to any channel of one of said digital trunks, and means including said common control unit for establishing a cross-office connection between one of said analog and one of said digital trunks including one of said conversion junctor circuits, said common control unit operating said time slot link switch connected to said gating means to govern the admission and release of said analog and digital signals into and out of said decoder and encoder means, respectively, in step with said sequences of pulses corresponding to the channel of said time division multiplex line associated with said digital trunk involved in said cross-office connection.
Claim 10
Dependent Claim
201 words
A communication switching system for interconnecting incoming and outgoing time division multiplex lines by space division switching means comprising a plurality of incoming and outgoing digital trunk circuits, there being as many digital trunk circuits as the sum of the number of incoming and outgoing multiplexed channels carried by said multipLex lines, each of said incoming digital trunk circuits including storage means for receiving the multiplex signals from an associated multiplex line channel, means for selecting an idle outgoing digital trunk circuit and connecting said selected outgoing digital trunk circuit to a calling one of said incoming digital trunk circuits, and means including a time slot link switch having a plurality of horizontal and vertical paths therein, said horizontal paths each being connected to a respective source of time slot signals in synchronism with the time slot signals of a respective one of said outgoing digital trunk circuits and said vertical paths each being connectable to a respective one of said storage means in said incoming digital trunk circuits for applying to said storage means in said calling one of said incoming digital trunk circuits a sequence of readout pulses dependent upon the selected one of said outgoing digital trunk circuits.
Claim 11
Dependent Claim
201 words
A communication switching system for interconnecting incoming and outgoing time division multiplex lines by space division switching means comprising a plurality of incoming and outgoing digital trunk circuits, there being as many digital trunk circuits as the sum of the number of incoming and outgoing multiplexed channels carried by said multipLex lines, each of said incoming digital trunk circuits including storage means for receiving the multiplex signals from an associated multiplex line channel, means for selecting an idle outgoing digital trunk circuit and connecting said selected outgoing digital trunk circuit to a calling one of said incoming digital trunk circuits, and means including a time slot link switch having a plurality of horizontal and vertical paths therein, said horizontal paths each being connected to a respective source of time slot signals in synchronism with the time slot signals of a respective one of said outgoing digital trunk circuits and said vertical paths each being connectable to a respective one of said storage means in said incoming digital trunk circuits for applying to said storage means in said calling one of said incoming digital trunk circuits a sequence of readout pulses dependent upon the selected one of said outgoing digital trunk circuits.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |