Patents by Inventor Tadeusz H. Szymanski

Tadeusz H. Szymanski has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10708192
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Grant
    Filed: January 18, 2019
    Date of Patent: July 7, 2020
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20190230042
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Application
    Filed: January 18, 2019
    Publication date: July 25, 2019
    Inventor: Tadeusz H. Szymanski
  • Patent number: 10237199
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Grant
    Filed: January 12, 2017
    Date of Patent: March 19, 2019
    Inventor: Tadeusz H. Szymanski
  • Patent number: 10182021
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. Each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates between Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An algorithm for scheduling N traffic flows with traffic rates is based upon recursive and fair decomposition of a traffic rate vector with N elements. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of XQs to be reduced. A shared column queue may be used in place of the XQs.
    Type: Grant
    Filed: August 18, 2017
    Date of Patent: January 15, 2019
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20170353400
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Application
    Filed: August 18, 2017
    Publication date: December 7, 2017
    Inventor: Tadeusz H. Szymanski
  • Patent number: 9781060
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Grant
    Filed: June 20, 2016
    Date of Patent: October 3, 2017
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20170230301
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Application
    Filed: January 12, 2017
    Publication date: August 10, 2017
    Inventor: TADEUSZ H. SZYMANSKI
  • Publication number: 20170135124
    Abstract: Schedule and channel assignment in a wireless mesh network (WMN) includes: forming a representation of a sequence of permutation matrices from an n×n rate matrix. The entries of the rate matrix define the bandwidth of links between nodes of the WMN. Each permutation matrix represents active radio links between nodes. The sequence of permutation matrices defines a sequence of radio links to provide desired bandwidth between nodes. Further, a representation of a sequence of partial permutation matrices corresponding to the sequence of permutation matrices is formed so that each of the permutation matrices can be decomposed into a group of partial permutation matrices. Each partial permutation matrix represents non-interfering radio links between the nodes. In each timeslot, the nodes are configured for radio transmission and reception in accordance with at least one of the partial permutation matrices in each group to transmit traffic between the nodes.
    Type: Application
    Filed: September 14, 2016
    Publication date: May 11, 2017
    Inventor: TADEUSZ H. SZYMANSKI
  • Patent number: 9584431
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analyzed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Grant
    Filed: July 6, 2015
    Date of Patent: February 28, 2017
    Inventor: Tadeusz H. Szymanski
  • Patent number: 9473990
    Abstract: Schedule and channel assignment (SCA) in a wireless mesh network (WMN) is disclosed. A method includes: forming a representation of a sequence of permutation matrices from an n×n rate matrix. The entries of the rate matrix define the bandwidth of links between the n nodes of the WMN. Each of the permutation matrices represents active radio links between the n nodes. The sequence of permutation matrices defines a sequence of radio links to provide the desired bandwidth of links between said n nodes. Further, a representation of a sequence of partial permutation matrices corresponding to the sequence of permutation matrices is formed in such a way that each of the permutation matrices can be decomposed into a group of partial permutation matrices. Each of the partial permutation matrices in a group represents non-interfering radio links between the n nodes.
    Type: Grant
    Filed: July 21, 2015
    Date of Patent: October 18, 2016
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20160301627
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Application
    Filed: June 20, 2016
    Publication date: October 13, 2016
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20150327123
    Abstract: Schedule and channel assignment (SCA) in a wireless mesh network (WMN) is disclosed. A method includes: forming a representation of a sequence of permutation matrices from an n×n rate matrix. The entries of the rate matrix define the bandwidth of links between the n nodes of the WMN. Each of the permutation matrices represents active radio links between the n nodes. The sequence of permutation matrices defines a sequence of radio links to provide the desired bandwidth of links between said n nodes. Further, a representation of a sequence of partial permutation matrices corresponding to the sequence of permutation matrices is formed in such a way that each of the permutation matrices can be decomposed into a group of partial permutation matrices. Each of the partial permutation matrices in a group represents non-interfering radio links between the n nodes.
    Type: Application
    Filed: July 21, 2015
    Publication date: November 12, 2015
    Inventor: TADEUSZ H. SZYMANSKI
  • Publication number: 20150312163
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Application
    Filed: July 6, 2015
    Publication date: October 29, 2015
    Inventor: TADEUSZ H. SZYMANSKI
  • Publication number: 20150304245
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each 10 pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Application
    Filed: April 27, 2015
    Publication date: October 22, 2015
    Inventor: TADEUSZ H. SZYMANSKI
  • Patent number: 9042380
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: May 26, 2015
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20140233377
    Abstract: Methods to achieve bounded router buffer sizes and Quality of Service guarantees for traffic flows in a packet-switched network are described. The network can be an Internet Protocol (IP) network, a Differentiated Services network, an MPLS network, wireless mesh network or an optical network. The routers can use input queueing, possibly in combination with crosspoint queueing and/or output queueing. Routers may schedule QoS-enabled traffic flows to ensure a bounded normalized service lead/lag. Each QoS-enabled traffic flow will buffer O(K) packets per router, where K is an integer bound on the normalized service lead/lag. Three flow-scheduling methods are analysed. Non-work-conserving flow-scheduling methods can guarantee a bound on the normalized service lead/lag, while work-conserving flow-scheduling methods typically cannot guarantee the same small bound.
    Type: Application
    Filed: December 2, 2013
    Publication date: August 21, 2014
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20140119347
    Abstract: Schedule and channel assignment in a wireless mesh network (WMN) includes: forming a representation of a sequence of permutation matrices from an n×n rate matrix. The entries of the rate matrix define the bandwidth of links between nodes of the WMN. Each permutation matrix represents active radio links between nodes. The sequence of permutation matrices defines a sequence of radio links to provide desired bandwidth between nodes. Further, a representation of a sequence of partial permutation matrices corresponding to the sequence of permutation matrices is formed so that each of the permutation matrices can be decomposed into a group of partial permutation matrices. Each partial permutation matrix represents non-interfering radio links between the nodes. In each timeslot, the nodes are configured for radio transmission and reception in accordance with at least one of the partial permutation matrices in each group to transmit traffic between the nodes.
    Type: Application
    Filed: October 29, 2013
    Publication date: May 1, 2014
    Inventor: Tadeusz H. Szymanski
  • Patent number: 8619566
    Abstract: Schedule and channel assignment (SCA) in a wireless mesh network (WMN) is disclosed. A method includes: forming a representation of a sequence of permutation matrices from a n×n rate matrix. The entries of the rate matrix define the bandwidth of links between the n nodes of the WMN. Each of the permutation matrices represents active radio links between the n nodes. The sequence of permutation matrices defines a sequence of radio links to provide the desired bandwidth of links between said n nodes. Further, a representation of a sequence of partial permutation matrices corresponding to the sequence of permutation matrices is formed in such a way that each of the permutation matrices can be decomposed into a group of partial permutation matrices. Each of the partial permutation matrices in a group represents non-interfering radio links between the n nodes.
    Type: Grant
    Filed: October 14, 2009
    Date of Patent: December 31, 2013
    Inventor: Tadeusz H. Szymanski
  • Publication number: 20130329748
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be routed. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Application
    Filed: May 29, 2013
    Publication date: December 12, 2013
    Inventor: Tadeusz H. Szymanski
  • Patent number: 8503440
    Abstract: A crossbar switch has N input ports, M output ports, and a switching matrix with N×M crosspoints. In an embodiment, each crosspoint contains an internal queue (XQ), which can store one or more packets to be touted. Traffic rates to be realized between all Input/Output (IO) pairs of the switch are specified in an N×M traffic rate matrix, where each element equals a number of requested cell transmission opportunities between each IO pair within a scheduling frame of F time-slots. An efficient algorithm for scheduling N traffic flows with traffic rates based upon a recursive and fair decomposition of a traffic rate vector with N elements, is proposed. To reduce memory requirements a shared row queue (SRQ) may be embedded in each row of the switching matrix, allowing the size of all the XQs to be reduced. To further reduce memory requirements, a shared column queue may be used in place of the XQs.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: August 6, 2013
    Inventor: Tadeusz H. Szymanski