US4855996A
Expired / Lapsed
US
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Time division multiplex arrangement
Assignee: AT&T Inc
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Filing: 1988-08-03
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Granted: 1989-08-08
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Expires: 2008-08-03
Abstract
Abstract Modems, data service units, application modules and other data communication devices, installed in a common equipment cabinet, are interconnected by way of a time division multiplexed bus. Time slots assigned to the various devices recur at a number of regularly-spaced access periods across each time division multiplex frame. The rate at which the access periods occur and the total number of access periods that make up each frame are chosen in such a way as to accommodate a mix of devices having respective bus access rates wherein there is at least one pair of rates for which neither rate of the pair is a whole number multiple of the other. The process of allocating access periods to the time slots is carried out using a known lemma to identify linear Diophantine equation solutions.
Inventors
- 👤 William Douskalis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:23
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/16; H04J3/1605; H04J3/1623; H04J3/1629
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
102 words
A time division multiplex arrangement comprising a communication medium, a plurality of devices for generating respective streams of data at respective synchronous bit rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for causing each said device to apply to said medium, during each of a succession of access periods allocated to that device, a constant number of bits of the respective bit stream, the access periods allocated to each said device occurring at equally spaced time intervals, said time intervals being of equal duration.
Claim 2
Dependent Claim
102 words
A time division multiplex arrangement comprising a communication medium, a plurality of devices for generating respective streams of data at respective synchronous bit rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for causing each said device to apply to said medium, during each of a succession of access periods allocated to that device, a constant number of bits of the respective bit stream, the access periods allocated to each said device occurring at equally spaced time intervals, said time intervals being of equal duration.
Claim 3
Dependent Claim
12 words
The invention of claim 1 wherein said communication medium is a bus.
Claim 4
Dependent Claim
52 words
The invention of claim 2 further comprising means for applying to said bus during each access period allocated to an individual one of said devices one of a plurality of signals identifying a respective function to be performed by that device when it accesses said bus during the access periods allocated thereto.
Claim 5
Dependent Claim
60 words
The invention of claim 2 wherein said means for causing includes means for applying to said bus, for each device, an address assigned to the access periods allocated to that device and means associated with said each device for causing it to access said bus when the address of the access periods allocated to that device appears on said bus.
Claim 6
Dependent Claim
211 words
A time division multiplex arrangement for use with a communication medium, said arrangement comprising a plurality of devices adapted to access said communication medium at respective access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said access rates, said access periods occurring in frames of F access period each, F being a predetermined number, means of allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the access rate of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and means for causing each said device to access said communication medium during its respective set of access periods.
Claim 7
Dependent Claim
211 words
A time division multiplex arrangement for use with a communication medium, said arrangement comprising a plurality of devices adapted to access said communication medium at respective access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said access rates, said access periods occurring in frames of F access period each, F being a predetermined number, means of allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the access rate of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and means for causing each said device to access said communication medium during its respective set of access periods.
Claim 8
Dependent Claim
41 words
The invention of claim 5 wherein, for each said device, a constant number of information bits is transferred between that device and said communication medium during each of the access periods allocated to that device for a succession of said frames.
Claim 9
Dependent Claim
94 words
The invention of claim 6 wherein said means for allocating includes means for allocating a particular set of access periods to an individual one of said devices only if the spacing between a selected one of the access periods of said particular set and a selected one of the access periods of each set then allocated to others of said devices is not divisible by the greatest common divisor of the walk time associated with said individual one of said devices and the walk time associated with each of said others of said devices.
Claim 10
Dependent Claim
54 words
The invention of claim 7 further comprising means for applying to said communication medium during each access period allocated to an individual one of said devices one of a plurality of signals identifying a respective function to be performed by that device when it accesses said communication medium during the access periods allocated thereto.
Claim 11
Dependent Claim
29 words
The invention of claim 8 wherein said respective function is the transferring of a predetermined number of bits between said communication medium and said individual one of said devices.
Claim 12
Dependent Claim
72 words
The invention of claim 8 wherein said means for causing said devices to access said communication medium includes means for applying to said communication medium, for each said device, an address assigned to the set of access periods allocated to that device and means associated with said each device for causing it to access said communication medium when the address of the set allocated to that device appears on said communication medium.
Claim 13
Dependent Claim
67 words
The invention of claim 5 further comprising means for applying to said communication medium during a selected one of said access periods not then allocated to any of said devices a signal identifying a function to be performed by a selected one of said devices only during said selected access period and means for causing said selected device to respond to said signal to perform said function.
Claim 14
Dependent Claim
33 words
The invention of claim 11 wherein said function is the reading by said selected device from said communication medium of an address associated with the set of access periods allocated to said device.
Claim 15
Dependent Claim
41 words
The invention of claim 11 wherein said means for causing said selected device to respond includes means for applying to said communication medium an address associated with said selected device and means associated with said selected device for recognizing said address.
Claim 16
Dependent Claim
234 words
A time division multiplex arrangement comprising a bus, a plurality of devices adapted to access said bus at respective bus access rates, means for defining a succession of access periods occurring at a predetermined access period rate, said access periods occurring in frames of F access periods each, F being a predetermined number, means for allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rate of the respective device and the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and means for causing each of said devices to access said bus during its respective set of access periods, characterized in that there is at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, and further characterized in that said number F and said access period rate are such that each pair of sets in a frame can be comprised of mutually exclusive access periods within that frame and such that the spacing between each individual set in one frame and the corresponding set in the subsequent frame is equal to the walk time associated with said individual set.
Claim 17
Dependent Claim
234 words
A time division multiplex arrangement comprising a bus, a plurality of devices adapted to access said bus at respective bus access rates, means for defining a succession of access periods occurring at a predetermined access period rate, said access periods occurring in frames of F access periods each, F being a predetermined number, means for allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rate of the respective device and the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and means for causing each of said devices to access said bus during its respective set of access periods, characterized in that there is at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, and further characterized in that said number F and said access period rate are such that each pair of sets in a frame can be comprised of mutually exclusive access periods within that frame and such that the spacing between each individual set in one frame and the corresponding set in the subsequent frame is equal to the walk time associated with said individual set.
Claim 18
Dependent Claim
40 words
The invention of claim 14 wherein, for each said device, a constant number of information bits is transferred between that device and said bus during each of the access periods allocated to that device for a succession of said frames.
Claim 19
Dependent Claim
52 words
The invention of claim 14 wherein said access period rate is a whole number multiple of the least common multiple of all of said bus access rates and wherein said number F is a whole number multiple of the least common multiple of the walk times associated with all of said sets.
Claim 20
Dependent Claim
94 words
The invention of claim 16 wherein said means for allocating includes means for allocating a particular set of access periods to an individual one of said devices only if the spacing between a selected one of the access periods of said particular set and a selected one of the access periods of each set then allocated to others of said devices is not divisible by the greatest common divisor of the walk time associated with said individual one of said devices and the walk time associated with each of said others of said devices.
Claim 21
Dependent Claim
52 words
The invention of claim 17 further comprising means for applying to said bus during each access period allocated to a particular one of said devices one of a plurality of signals identifying a respective function to be performed by that device when it accesses said bus during the access periods allocated thereto.
Claim 22
Dependent Claim
28 words
The invention of claim 18 wherein said respective function is the transferring of a predetermined number of bits between said bus and said individual one of said devices.
Claim 23
Dependent Claim
68 words
The invention of claim 18 wherein said means for causing said devices to access said bus includes means for applying to said bus, for each said device, an address assigned to the set of access periods allocated to that device and means associated with said each device for causing it to access said bus when the address of the set allocated to that device appears on said bus.
Claim 24
Dependent Claim
66 words
The invention of claim 16 further comprising means for applying to said bus during a selected one of said access periods not then allocated to any of said devices a signal identifying a function to be performed by a selected one of said devices only during said selected access period and means for causing said selected device to respond to said signal to perform said function.
Claim 25
Dependent Claim
32 words
The invention of claim 21 wherein said function is the reading by said selected device from said bus of an address associated with the set of access periods allocated to said device.
Claim 26
Dependent Claim
40 words
The invention of claim 21 wherein said means for causing said selected device to respond includes means for applying to said bus an address associated with said selected device and means associated with said selected device for recognizing said address.
Claim 27
Dependent Claim
240 words
A time division multiplex arrangement comprising, a bus, a plurality of devices adapted to access said bus at respective bus access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said bus access rates, said access periods occurring in frames of F access periods, each, F being a predetermined number, means for allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rates of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and means for applying to said bus during the set of access periods allocated to each said device an address associated with that set and a signal identifying a function to be performed by that device, said each device being adapted to perform said function when said address appears on said bus.
Claim 28
Dependent Claim
240 words
A time division multiplex arrangement comprising, a bus, a plurality of devices adapted to access said bus at respective bus access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, means for defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said bus access rates, said access periods occurring in frames of F access periods, each, F being a predetermined number, means for allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rates of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and means for applying to said bus during the set of access periods allocated to each said device an address associated with that set and a signal identifying a function to be performed by that device, said each device being adapted to perform said function when said address appears on said bus.
Claim 29
Independent Claim
108 words
A method for use in a time division multiplex arrangement of a type which includes a communication medium and a plurality of devices for generating respective streams of data at respective synchronous bit rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, causing said device to apply said medium, during each of a succession of access periods allocated to that device, a constant number of bits of the respective bit stream, the access periods allocated to each said device occurring at equally spaced time intervals, said time intervals being of equal duration.
Claim 30
Independent Claim
108 words
A method for use in a time division multiplex arrangement of a type which includes a communication medium and a plurality of devices for generating respective streams of data at respective synchronous bit rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, causing said device to apply said medium, during each of a succession of access periods allocated to that device, a constant number of bits of the respective bit stream, the access periods allocated to each said device occurring at equally spaced time intervals, said time intervals being of equal duration.
Claim 31
Dependent Claim
65 words
The invention of claim 25 wherein said communication medium is a bus and wherein said method includes the further step of applying to said bus during each access period allocated to an individual one of said devices one of a plurality of signals identifying a respective function to be performed by that device when it accesses said bus medium during the access periods allocated thereto.
Claim 32
Independent Claim
215 words
A method for use in a time division multiplex arrangement of the type comprising a bus and a plurality of devices adapted to access said bus at respective bus access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, said method comprising the steps of defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said bus access rates, said access periods occurring in frames of F access periods each, F being a predetermined number, allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rate of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and causing each said device to access said bus during its respective set of access periods.
Claim 33
Independent Claim
215 words
A method for use in a time division multiplex arrangement of the type comprising a bus and a plurality of devices adapted to access said bus at respective bus access rates, there being at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, said method comprising the steps of defining a succession of access periods occurring at a predetermined access period rate which is a whole number multiple of the least common multiple of all of said bus access rates, said access periods occurring in frames of F access periods each, F being a predetermined number, allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the bus access rate of the respective device, the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and said number F being a whole number multiple of the least common multiple of the walk times associated with all of said devices, and causing each said device to access said bus during its respective set of access periods.
Claim 34
Dependent Claim
40 words
The invention of claim 27 wherein, for each said device, a constant number of information bits is transferred between that device and said bus during each of the access periods allocated to that device for a succession of said frames.
Claim 35
Dependent Claim
93 words
The invention of claim 28 wherein said allocating step includes the step of allocating a particular set of access periods to an individual one of said devices only if the spacing between a selected one of the access periods of said particular set and selected one of the access periods of each set then allocated to others of said devices is not divisible by the greatest common divisor of the walk time associated with said individual one of said devices and the walk time associated with each of said others of said devices.
Claim 36
Dependent Claim
53 words
The invention of claim 29 comprising the further step of applying to said bus during each access period allocated to an individual one of said devices one of a plurality of signals identifying a respective function to be performed by that device when it accesses said bus during the access periods allocated thereto.
Claim 37
Dependent Claim
28 words
The invention of claim 30 wherein said respective function is the transferring of a predetermined number of bits between said bus and said individual one of said devices.
Claim 38
Dependent Claim
64 words
The invention of claim 30 wherein said step of causing each said device to access said bus includes the steps of applying to said bus, for each said device, an address assigned to the set of access periods allocated to that device, and causing each device to access said bus when the address of the set allocated to that device appears on said bus.
Claim 39
Dependent Claim
65 words
The invention of claim 27 comprising the further steps of applying to said bus during a selected one of said access periods not then allocated to any of said devices a signal identifying a function to be performed by a selected one of said devices only during said selected access period and causing said selected device to respond to said signal to perform said function.
Claim 40
Dependent Claim
32 words
The invention of claim 33 wherein said function is the reading by said selected device from said bus of an address associated with the set of access periods allocated to said device.
Claim 41
Independent Claim
247 words
A method for use in a time division multiplex arrangement of the type which comprises a communication medium, a plurality of devices adapted to access said communication medium at respective access rates and means for defining a succession of access periods occurring at a predetermined access period rate, said access periods occurring in frames of F access periods each, F being a predetermined number, the method comprising the steps of allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the access rate of the respective device and the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and causing each of said devices to access said communication medium during its respective set of access periods, characterized in that there is at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, and further characterized in that said number F and said access period rate are such that each pair of sets in a frame can be comprised of mutually exclusive access periods within that frame and such that the spacing between each individual set in one frame and the corresponding set in the subsequent frame is equal to the walk time associated with said individual set.
Claim 42
Independent Claim
247 words
A method for use in a time division multiplex arrangement of the type which comprises a communication medium, a plurality of devices adapted to access said communication medium at respective access rates and means for defining a succession of access periods occurring at a predetermined access period rate, said access periods occurring in frames of F access periods each, F being a predetermined number, the method comprising the steps of allocating to each said device a respective set of the access periods of an individual one of said frames and the corresponding sets of access periods in subsequent frames, the access periods of each set recurring at the access rate of the respective device and the spacing between the access periods of each set being a walk time associated with that set and with the respective device, and causing each of said devices to access said communication medium during its respective set of access periods, characterized in that there is at least one pair of said rates for which neither rate of the pair is a whole number multiple of the other, and further characterized in that said number F and said access period rate are such that each pair of sets in a frame can be comprised of mutually exclusive access periods within that frame and such that the spacing between each individual set in one frame and the corresponding set in the subsequent frame is equal to the walk time associated with said individual set.
Claim 43
Dependent Claim
40 words
The invention of claim 35 wherein, for each device, a constant number of information bits is transferred between that device and said communication medium during each of the access periods allocated to the device for a succession of said frames.
Claim 44
Dependent Claim
51 words
The invention of claim 35 wherein said access period rate is a whole number multiple of the least common multiple of all of said access rates and wherein said number F is a whole number multiple of the least common multiple of the walk times associated with all of said sets.
Claim 45
Dependent Claim
91 words
The invention of claim 37 wherein in said allocating step a particular set of access periods is allocated to an individual one of said devices only if the spacing between a selected one of the access periods of said particular set and selected one of the access periods of each set then allocated to others of said devices is not divisible by the greatest common divisor of the walk time associated with said individual one of said devices and the walk time associated with each of said others of said devices.
Claim 46
Dependent Claim
55 words
The invention of claim 38 comprising the further step of applying to said communication medium, during each access period allocated to a particular one of said devices, one of a plurality of signals identifying a respective function to be performed by that device when it accesses said communication medium during the access periods allocated thereto.
Claim 47
Dependent Claim
29 words
The invention of claim 39 wherein said respective function is the transferring of a predetermined number of bits between said communication medium and said individual one of said devices.
Claim 48
Dependent Claim
69 words
The invention of claim 39 wherein said step of causing each of said devices to access said communication medium includes the steps of applying to said communication medium, for each said device, an address assigned to the set of access periods allocated to that device and causing each device to access said communication medium when the address of the set allocated to that device appears on said communication medium.
Claim 49
Dependent Claim
66 words
The invention of claim 37 comprising the further steps of applying to said communication medium during a selected one of said access periods not then allocated to any of said devices a signal identifying a function to be performed by a selected one of said devices only during said selected access period and causing said selected device to respond to said signal to perform said function.
Claim 50
Dependent Claim
33 words
The invention of claim 42 wherein said function is the reading by said selected device from said communication medium of an address associated with the set of access periods allocated to said device.
References Cited (Backward Citations)
US4763322A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |