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US6317416B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Fair queue servicing using dynamic weights (DWFQ)

Assignee: Nokia Canada Inc
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Filing: 1996-10-11
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Granted: 2001-11-13
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Expires: 2016-10-11
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Abstract

Abstract In a method of fair queue servicing at a queuing point in a multi-service class packet switched network, incoming packets are received in buffers and outgoing packets are scheduled by a weighted fair queue scheduler. Real-time information of buffer usage along with the minimum bandwidth requirement is used to dynamically modify the weights of the weighted fair queue scheduler.

Inventors

  • 👤 Natalie Giroux
  • 👤 Raymond R. Liao
  • 👤 Mustapha Aissaoui

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 21:18
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L12/5602; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04L2012/5678; H04L2012/5679; H04L2012/5681

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 94 words
A method of fair queue servicing at a queuing point in a multi-service class packet switched network, comprising the steps of: enqueuing incoming packets in buffers associated with respective service classes; transmitting outgoing packets from said buffers in accordance with a schedule determined by weights used by a weighted fair queue scheduler; determining in real-time buffer usage and a minimum bandwidth requirement for each service class; and dynamically modifying the weights used by said weighted fair queue scheduler in real-time so as to cause buffer queue size to move toward a predetermined target value.
Claim 2
Independent Claim 94 words
A method of fair queue servicing at a queuing point in a multi-service class packet switched network, comprising the steps of: enqueuing incoming packets in buffers associated with respective service classes; transmitting outgoing packets from said buffers in accordance with a schedule determined by weights used by a weighted fair queue scheduler; determining in real-time buffer usage and a minimum bandwidth requirement for each service class; and dynamically modifying the weights used by said weighted fair queue scheduler in real-time so as to cause buffer queue size to move toward a predetermined target value.
Claim 3
Dependent Claim 32 words
A method as claimed in claim 1 , wherein the minimum bandwidth requirement for at least one service class is determined during connection admission control of a connection to said queuing point.
Claim 4
Dependent Claim 21 words
A method as claimed in claim 1 , wherein said weights are also modified in accordance with real-time service class information.
Claim 5
Dependent Claim 34 words
A method as claimed in claim 1 , wherein buffer usage is monitored by a queue growth monitor, said queue growth monitor performing real-time estimation of queue growth every sampling interval T s .
Claim 6
Dependent Claim 23 words
A method as claimed in claim 1 , wherein said packet switched network is an ATM network and said packets are ATM cells.
Claim 7
Dependent Claim 148 words
A method as claimed in claim 1 , wherein the weights of the weighted fair queue scheduler are modified by carrying out the following steps during a series of sampling intervals: a) determine whether the queue growth is positive, and if so adjust the weight to bring the queue size to said predetermined target value TQSi in accordance with the relationship Wi=max{Ai+Qi+ΔQi−TQsi), min_Wi}, wherein Wi is the weight, Ai is the number of arrivals during a previous sampling period Ts, Qi is the queue size at the end of the sampling period Ts, ΔQi is the change in queue size during the sampling period Ts, or else if the queue growth is not positive, adjusting the weight to bring the queue size to the predetermined target value TQSi in accordance with the relationship Wi=max{Ai+Qi−TQsi), min_Wi}; and b) determining the difference ΔWi=Wi−min_Wi, where Wi is determined in step a).
Claim 8
Dependent Claim 38 words
A method as claimed in claim 1 , wherein cell transfer delay cell loss ratio requirements for each class of service are stored and taken into account in dynamically modifying the weights of said weighted fair queue scheduler.

References Cited (Backward Citations)

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US5335224A Cited
US5623668A Cited
US5463620A Cited
US5432790A Cited
US5517495A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-11-12 2005-05-14 2005-11-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-11-12 2009-05-14 2009-11-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-11-12 2013-05-14 2013-11-13 $7700.00 Window Closed / Lapsed

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