US5001707A
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Method of providing reserved bandwidth in a dual bus system
Assignee: Nortel Networks Technology Corp
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Filing: 1989-11-02
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Granted: 1991-03-19
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Expires: 2009-11-02
Abstract
Abstract A method provides reserved bandwidth in a system having dual unidirectional and oppositely oriented buses. The method is intended to enhance the proposed standard, DQDB Metropolitan Area Network. A portion of the bandwidth shared by the stations in accordance with the proposed standard is reserved for distribution to stations on an as required basis. Each station making a request for bandwidth is allocated a part of the reserved bandwidth. Empty isochronous cells are used to provide the reserved bandwidth on the buses.
Inventors
- 👤 Rungnoj Kositpaiboon
- 👤 Richard Breault
- 👤 Van P. T. Phung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:55
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/2852; H04J; H04J3/00; H04J3/24; H04J3/247; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5603; H04L2012/5609; H04L2012/5613; H04L2012/5629; H04L2012/5631; H04L2012/5632; H04L2012/5672
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
111 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth requested by the stations; and at each station, counting each reserved bandwidth cell used until reaching the reserved bandwidth value.
Claim 2
Independent Claim
111 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth requested by the stations; and at each station, counting each reserved bandwidth cell used until reaching the reserved bandwidth value.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1 wherein the step of generating a number of reserved bandwidth cells provides cells at a beginning of the cell generation cycle.
Claim 4
Dependent Claim
56 words
A method as claimed in claim 2 wherein the number of reserved bandwidth cells is X H and the cell generation cycle is Y H , calculated from ##EQU6## where C b is the bus capacity for unreserved and reserved bandwidth cells and C i are the bandwidths requested by each station i of N stations.
Claim 5
Dependent Claim
47 words
A method as claimed in claim 2 wherein the number of reserved bandwidth cells is Z g and the cell generation cycle is Y b , where Y b is an integer constant and Z g is the sum of the reserved bandwidth values for the stations.
Claim 6
Dependent Claim
26 words
A method as claimed in claim 1 wherein the step of generating a number of reserved bandwidth cells provides cells distributed throughout the cell generation cycle.
Claim 7
Dependent Claim
89 words
A method as claimed in claim 5 wherein the cells are distributed by generating a reserved bandwidth cell, then Z H non-reserved cell until Y H cells are generated, where X H is the number of reserved bandwidth cells and Y H is calculated from ##EQU7## where C b is the bus capacity for unreserved and reserved bandwidth cells and C i are the bandwidths requested by each station i of N stations and Z H equals the greatest integer less than (Y H /X H ), minus one.
Claim 8
Dependent Claim
73 words
A method as claimed in claim 5 wherein the cells are distributed by generating a reserved bandwidth cell, then Z s nonreserved cell until Y b cells are generated, where Y b is an integer constant defining the cell generation cycle and Z s equals the greatest integer less than (Y b /Z g ), minus one and Z g is the sum of the reserved bandwidth values for the stations reserving bandwidth.
Claim 9
Dependent Claim
34 words
A method as claimed in claim 1 further comprising the step of providing each station with a local cycle value calculated in dependence upon an amount of reserved bandwidth remaining available at the station.
Claim 10
Dependent Claim
46 words
A method as claimed in claim 8 further comprising the steps of: at each station, counting each reserved bandwidth cell received until reaching its local cycle value; and then restarting the steps of counting the reserved bandwidth cells used and counting the reserved bandwidth cells received.
Claim 11
Dependent Claim
64 words
A method as claimed in claim 9 wherein the reserved bandwidth value is X i and the local cycle value is Y i , respectively, for each station i calculated from C i /B i =X i /Y i , where C i is the actual bandwidth requested by the station i; and B i is a unused reserved bandwidth remaining at station i.
Claim 12
Dependent Claim
66 words
A method as claimed in claim 1 wherein the reserved bandwidth value is X i , for each station i, calculated from X i =Y b C i /C b , where C b is the bus capacity for unreserved and reserved bandwidth cells, C i is the bandwidth requested by the station i, and Y b is an integer constant defining the cell generation cycle.
Claim 13
Dependent Claim
22 words
A method as claimed in claim 11 further comprising the step of generating a reset cell to end the cell generation cycle.
Claim 14
Dependent Claim
24 words
A method as claimed in claim 12 wherein at each station, the reset cell restarts the step of counting the reserved bandwidth cells used.
Claim 15
Dependent Claim
16 words
A method as claimed in claim 1 wherein the reserved bandwidth cells are empty isochronous cells.
Claim 16
Independent Claim
163 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; providing each station with a local cycle value calculated in dependence upon an amount of reserved bandwidth remaining available at the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth reserved by the stations; at each station, counting each reserved bandwidth cell used until reaching the reserved bandwidth value; counting each reserved bandwidth cell received until reaching its local cycle value; and then restarting the steps of counting the reserved bandwidth cells used and counting the reserved bandwidth cells received.
Claim 17
Independent Claim
163 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; providing each station with a local cycle value calculated in dependence upon an amount of reserved bandwidth remaining available at the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth reserved by the stations; at each station, counting each reserved bandwidth cell used until reaching the reserved bandwidth value; counting each reserved bandwidth cell received until reaching its local cycle value; and then restarting the steps of counting the reserved bandwidth cells used and counting the reserved bandwidth cells received.
Claim 18
Dependent Claim
56 words
A method as claimed in claim 15 wherein the number of reserved bandwidth cells is X H and the cell generation cycle is Y H , calculated from ##EQU8## where C b is the bus capacity for unreserved and reserved bandwidth cells and C i are the bandwidths requested by each station i of N stations.
Claim 19
Dependent Claim
89 words
A method as claimed in claim 15 wherein the cells are distributed by generating a reserved bandwidth cell, then Z H non-reserved cell until Y H cells are generated, where X H is the number of reserved bandwidth cells and Y H is calculated from ##EQU9## where C b is the bus capacity for unreserved and reserved bandwidth cells and C i are the bandwidths requested by each station i of N stations and Z H equals the greatest integer less than (Y H /X H ), minus one.
Claim 20
Independent Claim
204 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; providing each station with a local cycle value calculated in dependence upon an amount of reserved bandwidth remaining available at the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth reserved by the stations; generating a reset cell to end the cell generation cycle, wherein at each station, the reset cell restarts the step of counting the reserved bandwidth cells used; and wherein the reserved bandwidth value is X i , for each station i, calculated from X i =Y b C i /C b , where C b is the bus capacity for unreserved and reserved bandwidth cells, C i is the bandwidth requested by the station i, and Y b is an integer constant defining the cell generation cycle.
Claim 21
Independent Claim
204 words
A method of providing reserved bandwidth in a communications system comprising dual unidirectional and oppositely directed buses and stations connected therebetween, in which bandwidth is provided by fixed format cells, the method comprising the step of: reserving bandwidth on a data bus in response to requests accepted from stations on a signal bus; providing each station with a reserved bandwidth value calculated in dependence upon an amount of bandwidth requested by the station; providing each station with a local cycle value calculated in dependence upon an amount of reserved bandwidth remaining available at the station; generating a number of reserved bandwidth cells per a cell generation cycle in dependence upon a total bandwidth reserved by the stations; generating a reset cell to end the cell generation cycle, wherein at each station, the reset cell restarts the step of counting the reserved bandwidth cells used; and wherein the reserved bandwidth value is X i , for each station i, calculated from X i =Y b C i /C b , where C b is the bus capacity for unreserved and reserved bandwidth cells, C i is the bandwidth requested by the station i, and Y b is an integer constant defining the cell generation cycle.
Claim 22
Dependent Claim
47 words
A method as claimed in claim 18 wherein the number of reserved bandwidth cells is Z g and the cell generation cycle is Y b , where Y b is an integer constant and Z g is the sum of the reserved bandwidth values for the stations.
Claim 23
Dependent Claim
73 words
A method as claimed in claim 18 wherein the cells are distributed by generating a reserved bandwidth cell, then Z s nonreserved cell until Y b cells are generated, where Y b is an integer constant defining the cell generation cycle and Z s equals the greatest integer less than (Y b /Z g ), minus one and Z g is the sum of the reserved bandwidth values for the stations reserving bandwidth.
Claim 24
Dependent Claim
38 words
A method as claimed in claim 1 wherein the fixed format cells comprise a first bit for indicating whether the cell is busy, a second bit for indicating cell type, and a third bit for indicating a request.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-18 | 1994-09-17 | 1995-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-18 | 1998-09-17 | 1999-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-18 | 2002-09-17 | 2003-03-19 | $7700.00 | Window Closed / Lapsed |