Patent US3781478A successfully refreshed from Google Patents.
US3781478A
Expired / Lapsed
US
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Multiplex communication system
Assignee: AT&T Inc
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Filing: 1972-07-07
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Granted: 1973-12-25
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Expires: 1992-07-07
Abstract
Abstract A time division multiplex communication system is described which includes a master timing station and a plurality of station sets serially interconnected forming a closed unidirectional transmission loop. Data and supervisory signals originating at a station set, together with digitally encoded speech, are time division multiplexed onto the loop, the information being inserted m bits at a time in a particular TDM channel associated with the called set. Each station set is arranged to store and repeat m bits at a time, the received digital bit stream, which may comprise data or supervisory signals while at the same time monitoring its assigned channel for the presence of information being transmitted thereto. A called set is arranged to extract and decode information contained in its channel, also m bits at a time. Since, for n station sets, the n X m bits on the loop at any given time can be stored within the stations, the number n of stations can be changed without alteration of any other equipment on the loop. Supervisory logic within each station set controls various set functions, including busy tone generation, ringer control, ringback indication, and so forth. One or more station sets may be modified to provide an interface with outside lines.
Inventors
- 👤 D Blahut
- 👤 F Froehlich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:17
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
165 words
A time division multiplex communication system for providing bidirectional communcation between any one of a plurality of n station sets and any other one of said station sets, comprising: a closed transmission loop serially interconnecting said station sets, means for establishing a plurality n of time division multiplex channels of width t circulating unidirectionally on said loop, each of said station sets including: 1. means for associating each of said station sets with any desired one of said channels, for receiving purposes, 2. means for inserting, m bits at a time, data in the one of said channels associated with a remote one of said station sets, 3. means for extracting, m bits at a time, data in the one of said channels associated therewith, and 4. means for storing and repeating, m bits at a time, data in the remaining ones of said channels, thereby facilitating variations in the number n of station sets on said loop independently of other changes in said system.
Claim 2
Dependent Claim
165 words
A time division multiplex communication system for providing bidirectional communcation between any one of a plurality of n station sets and any other one of said station sets, comprising: a closed transmission loop serially interconnecting said station sets, means for establishing a plurality n of time division multiplex channels of width t circulating unidirectionally on said loop, each of said station sets including: 1. means for associating each of said station sets with any desired one of said channels, for receiving purposes, 2. means for inserting, m bits at a time, data in the one of said channels associated with a remote one of said station sets, 3. means for extracting, m bits at a time, data in the one of said channels associated therewith, and 4. means for storing and repeating, m bits at a time, data in the remaining ones of said channels, thereby facilitating variations in the number n of station sets on said loop independently of other changes in said system.
Claim 3
Dependent Claim
24 words
means for inserting, m bits at a time, data in the one of said channels associated with a remote one of said station sets,
Claim 4
Dependent Claim
24 words
means for inserting, m bits at a time, data in the one of said channels associated with a remote one of said station sets,
Claim 5
Dependent Claim
11 words
providing an encoded digital signal representative of an analog input signal,
Claim 6
Dependent Claim
11 words
providing an encoded digital signal representative of an analog input signal,
Claim 7
Dependent Claim
71 words
The invention defined in claim 1 wherein said station sets further include: input means for generating a first analog signal in response to an audio input signal, encoder means for converting said first analog signal to said data to be inserted, decoder means for converting said extracted data to a second analog signal, and output means for receiving said second analog signal and for generating an audio output in response thereto.
Claim 8
Dependent Claim
9 words
a plurality of terminals serially interconnected on the loop,
Claim 9
Dependent Claim
9 words
a plurality of terminals serially interconnected on the loop,
Claim 10
Dependent Claim
10 words
the terminals including n-1 station sets and a master set,
Claim 11
Dependent Claim
10 words
the terminals including n-1 station sets and a master set,
Claim 12
Dependent Claim
27 words
The invention defined in claim 2 wherein at least one of said station sets includes means for deriving said audio input signal from an outside telephone line.
Claim 13
Dependent Claim
18 words
means for extracting, m bits at a time, data in the one of said channels associated therewith, and
Claim 14
Dependent Claim
18 words
means for extracting, m bits at a time, data in the one of said channels associated therewith, and
Claim 15
Dependent Claim
19 words
inserting said encoded signal, m bits at a time in said time slot associated with a distant station set,
Claim 16
Dependent Claim
19 words
inserting said encoded signal, m bits at a time in said time slot associated with a distant station set,
Claim 17
Dependent Claim
16 words
extracting a corresponding encoded signal, m bits at a time, from said time slot associated therewith,
Claim 18
Dependent Claim
16 words
extracting a corresponding encoded signal, m bits at a time, from said time slot associated therewith,
Claim 19
Dependent Claim
26 words
the master set including means for transmitting a framing indication of duration t on said loop in response to the reception of the preceding framing indication,
Claim 20
Dependent Claim
26 words
the master set including means for transmitting a framing indication of duration t on said loop in response to the reception of the preceding framing indication,
Claim 21
Dependent Claim
38 words
means for storing and repeating, m bits at a time, data in the remaining ones of said channels, thereby facilitating variations in the number n of station sets on said loop independently of other changes in said system.
Claim 22
Dependent Claim
38 words
means for storing and repeating, m bits at a time, data in the remaining ones of said channels, thereby facilitating variations in the number n of station sets on said loop independently of other changes in said system.
Claim 23
Dependent Claim
73 words
The invention defined in claim 3 wherein said channel establishing means includes: means in one of said station sets for initially generating a framing indication of width t and for subsequently generating framing indications in response to the receipt of the previous framing indication, and means in the remaining ones of said station sets for receiving said framing indications, storing said framing indications for a period t, and for regenerating said framing indications.
Claim 24
Dependent Claim
19 words
The invention defined in claim 4 wherein said data storing means includes an m bit, serial-in, serial-out shift register.
Claim 25
Dependent Claim
18 words
means within each of the station sets for storing for a duration t and regenerating the framing indication,
Claim 26
Dependent Claim
18 words
means within each of the station sets for storing for a duration t and regenerating the framing indication,
Claim 27
Dependent Claim
12 words
providing a decoded analog signal representative of said corresponding encoded signal, and
Claim 28
Dependent Claim
12 words
providing a decoded analog signal representative of said corresponding encoded signal, and
Claim 29
Dependent Claim
18 words
storing and regenerating digital signals, m bits at a time, in remaining ones of said TDM time slots.
Claim 30
Dependent Claim
18 words
storing and regenerating digital signals, m bits at a time, in remaining ones of said TDM time slots.
Claim 31
Dependent Claim
25 words
means within each station set for associating with each of said station sets a particular time interval of said duration t following the framing indication,
Claim 32
Dependent Claim
25 words
means within each station set for associating with each of said station sets a particular time interval of said duration t following the framing indication,
Claim 33
Dependent Claim
105 words
The invention defined in claim 1 wherein each of said station sets further includes: means operative in conjunction with said extracting means for monitoring the one of said channels associated with a remote one of said station sets for the existence of an idle condition, and means operative in conjunction with said inserting menas for generating simultaneously with the operation of said last-named means a code indicating to remaining ones of said station sets the busy status of said each station set, and for subsequently generating a code indicating to said remote station set the one of said channels associated with said each station set.
Claim 34
Dependent Claim
174 words
A time division multiplex communication system comprising: a plurality of station sets each including: repeater circuits serially interconnected on a closed unidirectional transmission loop, said repeaters including means for receiving a digital pulse train containing data signals and timing signals circulating on said loop, for storing said pulse train, m bits at a time, and for retransmitting said pulse train on said loop, means for separating said data signals from said timing signals in said pulse train, and supervisory logic means responsive to said separating means for processing portions of data in said pulse train selected in accordance with their relationship to said timing signals, said logic means including: a. means for inserting data originating in a first one of said station sets, m bits at a time, in the portion of said pulse train associated with a second one of said station sets, and b. means for extracting data originating in said second station set, m bits at a time, from the portion of said pulse train associated with said first station set.
Claim 35
Dependent Claim
174 words
A time division multiplex communication system comprising: a plurality of station sets each including: repeater circuits serially interconnected on a closed unidirectional transmission loop, said repeaters including means for receiving a digital pulse train containing data signals and timing signals circulating on said loop, for storing said pulse train, m bits at a time, and for retransmitting said pulse train on said loop, means for separating said data signals from said timing signals in said pulse train, and supervisory logic means responsive to said separating means for processing portions of data in said pulse train selected in accordance with their relationship to said timing signals, said logic means including: a. means for inserting data originating in a first one of said station sets, m bits at a time, in the portion of said pulse train associated with a second one of said station sets, and b. means for extracting data originating in said second station set, m bits at a time, from the portion of said pulse train associated with said first station set.
Claim 36
Dependent Claim
26 words
means within each station set for inserting m bits of data generated in the station sEt in the time interval associated with a distant station set,
Claim 37
Dependent Claim
26 words
means within each station set for inserting m bits of data generated in the station sEt in the time interval associated with a distant station set,
Claim 38
Dependent Claim
18 words
means within each station set for extracting m bits of data from the time interval associated therewith, and,
Claim 39
Dependent Claim
18 words
means within each station set for extracting m bits of data from the time interval associated therewith, and,
Claim 40
Dependent Claim
68 words
A system in accordance with claim 7 wherein said supervisory logic means further include: means in said first station set for generating a coded data signal indicative of said portion of said pulse train associated with said first station set, and means in said second station set for receiving said coded data signal and for identifying siad portion of said pulse train associated with said first station set.
Claim 41
Dependent Claim
7 words
A time division multiplex communication system including:
Claim 42
Dependent Claim
7 words
A time division multiplex communication system including:
Claim 43
Dependent Claim
40 words
means within each station set for storing and regenerating data, m bits at a time, during each of the remaining time intervals, whereby the n X m bits on the loop at any time are stored within the station sets.
Claim 44
Dependent Claim
40 words
means within each station set for storing and regenerating data, m bits at a time, during each of the remaining time intervals, whereby the n X m bits on the loop at any time are stored within the station sets.
Claim 45
Dependent Claim
9 words
The invention defined in claim 9 wherein m 1.
Claim 46
Dependent Claim
23 words
The invention defined in claim 9 wherein said storage and regeneration means within each of said station sets comprises a tristable repeater circuit.
Claim 47
Dependent Claim
26 words
The invention defined in claim 11 wherein at least one of said station sets further includes means for connecting said set to an outside telephone line.
Claim 48
Dependent Claim
46 words
The invention defined in claim 11 wherein said master station set includes: first means for initially generating a framing indication on said loop, second means for detecting an erroneous sequence of framing indications, and third means responseive to said second means for resetting said first means.
Claim 49
Dependent Claim
35 words
The invention defined in claim 13 wherein said tristable repeater circuit comprises: means for separating said framing indications from the remainder of said pulse stream, and means for extracting timing information from said framing indications.
Claim 50
Dependent Claim
24 words
The invention defined in claim 14 wherein said extracting means includes a crystal clock phase-locked to said framing indications on an asynchronous frame-to-frame basis.
Claim 51
Dependent Claim
65 words
The invention defined in claim 14 wherein said associating means includes counter means arranged to be reset by said framing indications and to respond to said timing information, means for storing the number of the time interval associated with a particular one of said station sets, and means jointly responsive to said storage means and said counter means for outpulsing during said associated time interval.
Claim 52
Dependent Claim
134 words
A time division multiplex communication system comprising: a closed unidirectional transmission loop adapted to transmit a digital bit stream, a master station set connected to said loop and arranged to initially generate a mark pulse of width t on said loop and to generate a series of succeeding mark pulses in response to the reception of each preceding one of said mark pulses, a plurality of n station sets serially interconnected on said loop and arranged to receive and extract said mark pulses from said bit stream, store said mark pulses for a period t, and regenerate and reinsert said mark pulses in said bit stream, thereby defining a frame interval between adjacent mark pulses of length (n-1)t comprised of n-1 TDM time slots each of width t, means within each station set for
Claim 53
Dependent Claim
134 words
A time division multiplex communication system comprising: a closed unidirectional transmission loop adapted to transmit a digital bit stream, a master station set connected to said loop and arranged to initially generate a mark pulse of width t on said loop and to generate a series of succeeding mark pulses in response to the reception of each preceding one of said mark pulses, a plurality of n station sets serially interconnected on said loop and arranged to receive and extract said mark pulses from said bit stream, store said mark pulses for a period t, and regenerate and reinsert said mark pulses in said bit stream, thereby defining a frame interval between adjacent mark pulses of length (n-1)t comprised of n-1 TDM time slots each of width t, means within each station set for
Claim 54
Dependent Claim
215 words
A time division multiplex communication system comprising: a plurality of n-1 station sets, a master station set, a closed loop unidirectional transmission link serially interconnecting said station sets and said master set and adapted to transmit a stream of digital bits, first means in said master station for initially generating a mark pulse, second means in said station sets for receiving said mark pulse, delaying said mark pulse for a time interval t, and retransmitting said mark pulse on said loop, third means in said master station for regenerating said mark pulse in response to the reception of the preceding mark pulse, thereby defining a frame length n-t between successive mark pulses comprised of n equal time slots of length t, fourth means in said station sets for associating each of said sets with a particular one of said time slots, fifth means in said station sets for inserting, m bits at a time, data generated in said station set in said time slot associated with a remote station set, sixth means in said station sets for extracting m bits at a time, data contained in said time slot associated therewith, and seventh means in said station sets for storing and regenerating, m bits at a time, data in remaining ones of said time slots.
Claim 55
Dependent Claim
215 words
A time division multiplex communication system comprising: a plurality of n-1 station sets, a master station set, a closed loop unidirectional transmission link serially interconnecting said station sets and said master set and adapted to transmit a stream of digital bits, first means in said master station for initially generating a mark pulse, second means in said station sets for receiving said mark pulse, delaying said mark pulse for a time interval t, and retransmitting said mark pulse on said loop, third means in said master station for regenerating said mark pulse in response to the reception of the preceding mark pulse, thereby defining a frame length n-t between successive mark pulses comprised of n equal time slots of length t, fourth means in said station sets for associating each of said sets with a particular one of said time slots, fifth means in said station sets for inserting, m bits at a time, data generated in said station set in said time slot associated with a remote station set, sixth means in said station sets for extracting m bits at a time, data contained in said time slot associated therewith, and seventh means in said station sets for storing and regenerating, m bits at a time, data in remaining ones of said time slots.
Claim 56
Dependent Claim
26 words
The invention defined in claim 18 wherein at least one of said station sets includes eight means for connecting said set to an outside telephone line.
Claim 57
Dependent Claim
42 words
The invention defined in claim 19 wherein said master station set further includes ninth means for detecting an erroneous sequence of said mark pulses and tenth means responsive to said ninth means for reestablishing a proper mark pulse sequence on said loop.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |