US3617643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time division switching system employing common transmission highways
Assignee: AT&T Inc
•
Filing: 1969-07-25
•
Granted: 1971-11-02
•
Expires: 1989-07-25
Abstract
Abstract In a time division switching system, speech samples from a subscriber station are first encoded and then stored, in digital coded form in a register in a transceiver. The output of this register is gated to a second register in the common talking bus or highway during a first portion of a time slot; the sample from this register in the common highway is gated in a later portion of the same time slot to a similar transceiver connected to the called subscriber. It is then subsequently decoded and applied to the called subscriber. Two-wire, four-wire, and conferencing arrangements are disclosed.
Inventors
- 👤 Walter R Nordquist
- 👤 Wing N Toy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:02
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
128 words
A time division switching system comprising a plurality of lines, first and second common transmission highways and means for interconnecting calling and called ones of said lines via said highways during an assigned time slot in a repetitive cycle of time slots, said interconnecting means comprising means for simultaneously transferring a signal sample from each of said calling and called lines to said first and second highways respectively, means for adding said calling line sample to said called line sample, means for transferring the resultant signal summation to said calling and called lines, means for subtracting the signal sample developed in each of said calling and called lines from said resultant signal summation and means for applying the resultant difference signals to the respective calling and called lines.
Claim 2
Dependent Claim
128 words
A time division switching system comprising a plurality of lines, first and second common transmission highways and means for interconnecting calling and called ones of said lines via said highways during an assigned time slot in a repetitive cycle of time slots, said interconnecting means comprising means for simultaneously transferring a signal sample from each of said calling and called lines to said first and second highways respectively, means for adding said calling line sample to said called line sample, means for transferring the resultant signal summation to said calling and called lines, means for subtracting the signal sample developed in each of said calling and called lines from said resultant signal summation and means for applying the resultant difference signals to the respective calling and called lines.
Claim 3
Dependent Claim
90 words
A time division communication system comprising a plurality of lines, a plurality of common highways accessible from said plurality of lines, means for transferring a signal sample from each of said plurality of lines to a corresponding preselected one of said plurality of highways during a first portion of a time slot in a repetitive cycle of time slots and means operative in a second portion of the same time slot for transferring said signal samples from said plurality of highways to corresponding, predetermined ones of said plurality of lines.
Claim 4
Dependent Claim
90 words
A time division communication system comprising a plurality of lines, a plurality of common highways accessible from said plurality of lines, means for transferring a signal sample from each of said plurality of lines to a corresponding preselected one of said plurality of highways during a first portion of a time slot in a repetitive cycle of time slots and means operative in a second portion of the same time slot for transferring said signal samples from said plurality of highways to corresponding, predetermined ones of said plurality of lines.
Claim 5
Dependent Claim
37 words
A time division communication system in accordance with claim 2 wherein each of said highways comprises register means, said signal samples from said plurality of lines being interchanged via said register means during said same time slot.
Claim 6
Dependent Claim
46 words
A time division communication system in accordance with claim 2 wherein each of said plurality of lines comprises means for coding and decoding said signal samples and further comprising means for registering said coded signal samples prior to transmission to said highways via said transferring means.
Claim 7
Dependent Claim
87 words
A time division communication system in accordance with claim 2 wherein each of said highways comprises register means, and further comprising means interconnecting said highway register means for combining said signal samples and buffer storage means for applying the resultant combined signal sample from said combining means to each of said plurality of lines via said register means in each of said highways, and wherein each of said lines comprises means for substracting the signal sample produced by the corresponding line from said resultant combined signal sample.
Claim 8
Dependent Claim
42 words
A time division communication system in accordance with claim 5 and further comprising means for storing the content of said buffer storage means and means for applying the content of said storing means to said combining means during a succeeding time slot.
Claim 9
Dependent Claim
103 words
A communication system comprising a plurality of stations, common highway meAns, means for coding signal samples from the associated stations, means for storing said signal samples, switching means, and means for enabling said switching means during distinct successive time intervals in a repetitive cycle to transfer said signal samples to and from said highway means, said coding means being connected between said storing means and each of said stations, said switching means being connected between said storing means and said highway means, and said highway means comprising register means for storing said coded signal samples intermediate transfers to and from said highway means.
Claim 10
Dependent Claim
103 words
A communication system comprising a plurality of stations, common highway meAns, means for coding signal samples from the associated stations, means for storing said signal samples, switching means, and means for enabling said switching means during distinct successive time intervals in a repetitive cycle to transfer said signal samples to and from said highway means, said coding means being connected between said storing means and each of said stations, said switching means being connected between said storing means and said highway means, and said highway means comprising register means for storing said coded signal samples intermediate transfers to and from said highway means.
Claim 11
Dependent Claim
43 words
A communication system in accordance with claim 7 wherein said highway means comprises a pair of common highways, and further comprising means interconnecting said highway register means for adding together said stored samples and means for applying the resultant sum to said highways.
References Cited (Backward Citations)
US3225144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |