Patents by Inventor Roberto Rojas

Roberto Rojas 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).

  • Publication number: 20110026437
    Abstract: Techniques are generally disclosed for disseminating link state information to one or more nodes of a network of nodes, the network of nodes interconnected via a plurality of communication channels.
    Type: Application
    Filed: July 30, 2009
    Publication date: February 3, 2011
    Inventors: Roberto Roja-Cessa, Nirwan Ansari, Zhen Qin
  • Publication number: 20110026539
    Abstract: Examples are disclosed for forwarding cells of partitioned data through a three-stage memory-memory-memory (MMM) input-queued Clos-network (IQC) packet switch. In some examples, each module of the three-stage MMM IQC packet switch includes a virtual queue and a manager that are configured in cooperation with one another to forward a cell from among cells of partitioned data through at least a portion of the switch. The cells of partitioned data may have been partitioned and stored at an input port for the switch and have a destination of an output port for the switch.
    Type: Application
    Filed: July 29, 2009
    Publication date: February 3, 2011
    Inventors: Roberto Rojas-Cessa, Ziqian Dong
  • Publication number: 20110026532
    Abstract: Examples are disclosed for forwarding data partitioned into one or more cells through at least a portion of a three-stage memory-memory-memory (MMM) input-queued Clos-network (IQC) packet switch. In some examples, each module of the three-stage MMM IQC packet switch includes a virtual queue and a manager that are configured in cooperation with one another to forward cells through at least a portion of the switch. The cells may have been partitioned and stored at an input port for the switch and destined for an output port for the switch.
    Type: Application
    Filed: July 29, 2009
    Publication date: February 3, 2011
    Inventors: Roberto Rojas-Cessa, Ziqian Dong
  • Publication number: 20100316061
    Abstract: Examples of are disclosed for configuring one or more routes through a three-stage Clos-network packet switch.
    Type: Application
    Filed: June 16, 2009
    Publication date: December 16, 2010
    Inventors: Roberto Rojas-Cessa, Chuan-Bi Lin
  • Patent number: 7843908
    Abstract: A configuration scheme for IQC switches that hierarchizes the matching process reduces configuration complexity by performing routing first and port matching afterwards in a three-stage Clos-network switch. This scheme applies the reduction concept of Clos networks to the matching process. This, in turn, results in a feasible size of schedulers for up to Exabit-capacity switches, an independent configuration of the middle stage modules from port matches, a reduction of the matching communication overhead between different stages, and a release of the switching function to the last-stage modules in a three-stage switch. The switching performance of the proposed approach using weight-based and weightless selection schemes is high under uniform and non-uniform traffic. The number of stages of a Clos-network switch can be reduced to two.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: November 30, 2010
    Inventors: Roberto Rojas-Cessa, Chuan-Bi Lin
  • Publication number: 20100277837
    Abstract: The present invention relates to a device arranged for converting an AC input voltage to a DC output voltage, comprising a bridgeless boost converter; and a surge protection system. The surge protection system comprises a first protection diode (Dprot1), where the anode is connected to a first AC input terminal and the cathode is connected to a positive boost output terminal (Obp); a second protection diode (Dprot2), where the anode is connected to a negative boost output terminal (Obn) and the cathode is connected to the first AC input terminal; a third protection diode (Dprot3), where the anode is connected to a second AC input terminal and the cathode is connected to the positive boost output terminal (Obp); and a fourth protection diode (Dprot4), where the anode is connected to the negative boost output terminal (Obn) and the cathode is connected to the second AC input terminal.
    Type: Application
    Filed: October 30, 2008
    Publication date: November 4, 2010
    Applicant: Eltek Valere AS
    Inventors: Erik Myhre, Jan Tore Brastad, Knut-Ivar Gjerde, Roberto Rojas
  • Publication number: 20100260198
    Abstract: A Clos-network packet switching system may include input modules coupled to a virtual output queue, central modules coupled to the input modules, and output modules coupled to the central modules, each output module having a plurality of cross-point buffers for storing a packet and one or more output ports for outputting the packet.
    Type: Application
    Filed: April 8, 2009
    Publication date: October 14, 2010
    Inventors: Roberto Rojas-Cessa, Chuan-bi Lin, Ziqian Dong
  • Publication number: 20090089139
    Abstract: A method of scheduling tasks for active network measurement includes identifying a first measurement task for measuring a first network parameter and a second measurement task for measuring a second network parameter. It is determined whether there is a conflict between the first measurement task and the second measurement task. A first execution time of the first measurement task and a second execution time of the second measurement task are also determined. A task schedule is generated based at least in part on the first execution time, the second execution time, and whether there is the conflict between the first measurement task and the second measurement task. The task schedule is further generated based at least in part on a color graph.
    Type: Application
    Filed: August 29, 2008
    Publication date: April 2, 2009
    Inventors: Roberto Rojas-Cessa, Nirwan Ansari, Zhen Qin
  • Publication number: 20090059921
    Abstract: Multicast traffic is expected to increase in packet networks, and therefore in switches and routers, by including broadcast and multimedia-on-demand services. Combined input-crosspoint buffered (CICB) switches can provide high performance under uniform multicast traffic. However this is often at the expense of N2 crosspoint buffers. An output-based shared-memory crosspoint-buffered (O-SMCB) packet switch is used where the crosspoint buffers are shared by two outputs and use no speedup. An embodiment of the proposed switch provides high performance under admissible uniform and non-uniform multicast traffic models while using 50% of the memory used in CICB switches that has dedicated buffers. Furthermore, the O-SMCB switch provides higher throughput than an existing SMCB switch where the buffers are shared by inputs.
    Type: Application
    Filed: August 29, 2008
    Publication date: March 5, 2009
    Inventors: Ziqian Dong, Roberto Rojas-Cessa
  • Publication number: 20080303628
    Abstract: A configuration scheme for IQC switches that hierarchizes the matching process reduces configuration complexity by performing routing first and port matching afterwards in a three-stage Clos-network switch. This scheme applies the reduction concept of Clos networks to the matching process. This, in turn, results in a feasible size of schedulers for up to Exabit-capacity switches, an independent configuration of the middle stage modules from port matches, a reduction of the matching communication overhead between different stages, and a release of the switching function to the last-stage modules in a three-stage switch. The switching performance of the proposed approach using weight-based and weightless selection schemes is high under uniform and non-uniform traffic. The number of stages of a Clos-network switch can be reduced to two.
    Type: Application
    Filed: June 6, 2008
    Publication date: December 11, 2008
    Inventors: Roberto Rojas-Cessa, Chuan-Bi Lin
  • Patent number: 7046661
    Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: May 16, 2006
    Assignee: Polytechnic University
    Inventors: Eiji Oki, Hung-Hsiang Jonathan Chao, Roberto Rojas-Cessa
  • Patent number: 7006514
    Abstract: A Pipelined-based Maximal-sized Matching (PMM) scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with a maximal matching scheme. In the PMM approach, arbitration may operate in a pipelined manner. Each subscheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides the matching result. The subscheduler can adopt a pre-existing efficient maximal matching algorithm such as iSLIP and DRRM. PMM maximizes the efficiency of the adopted arbitration scheme by allowing sufficient time for a number of iterations. PMM preserves 100% throughput under uniform traffic and fairness for best-effort traffic.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: February 28, 2006
    Assignee: Polytechnic University
    Inventors: Eiji Oki, Roberto Rojas-Cessa, Jonathan Chao Hung-Hsiang
  • Patent number: 6940851
    Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: September 6, 2005
    Assignee: Polytechnic University
    Inventors: Eiji Oki, Hung-Hsiang Jonathan Chao, Roberto Rojas-Cessa
  • Patent number: 6757185
    Abstract: A synchronized control method for a three-phase three-level boost-type rectifier with reduced input current ripple and balanced output voltages is disclosed. The proposed control allows simplifying the control circuit as much as possible without compromising the rectifier performance. In fact, besides simplicity, the control method featured synchronized command signals to de switching devices, minimized input current ripple, full controllability of the output voltage, dynamic balance of the output center point, constant switching frequency, simplified design of EMC filters, good transient and steady state performance, and low cost. The invention described first the most important configurations that the three-phase three-level boost-type rectifier may assume and studied the converter's operation. The concept involved for output voltage, input current, neutral point balance and control system design was presented.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: June 29, 2004
    Assignee: E.E.S. Sistemas de Energia Ltda.
    Inventor: Manuel Roberto Rojas Romero
  • Publication number: 20030128563
    Abstract: A synchronized control method for a three-phase three-level boost-type rectifier with reduced input current ripple and balanced output voltages is disclosed. The proposed control allows simplifying the control circuit as much as possible without compromising the rectifier performance. In fact, besides simplicity, the control method featured synchronized command signals to de switching devices, minimized input current ripple, full controllability of the output voltage, dynamic balance of the output center point, constant switching frequency, simplified design of EMC filters, good transient and steady state performance, and low cost. The invention described first the most important configurations that the three-phase three-level boost-type rectifier may assume and studied the converter's operation. The concept involved for output voltage, input current, neutral point balance and control system design was presented.
    Type: Application
    Filed: October 18, 2002
    Publication date: July 10, 2003
    Inventor: Manuel Roberto Rojas Romero
  • Publication number: 20030021266
    Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.
    Type: Application
    Filed: July 23, 2001
    Publication date: January 30, 2003
    Applicant: Polytechnic University
    Inventors: Eiji Oki, Hung-Hsiang Jonathan Chao, Roberto Rojas-Cessa
  • Publication number: 20020181483
    Abstract: A Pipelined-based Maximal-sized Matching (PMM) scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with a maximal matching scheme. In the PMM approach, arbitration may operate in a pipelined manner. Each subscheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides the matching result. The subscheduler can adopt a pre-existing efficient maximal matching algorithm such as iSLIP and DRRM. PMM maximizes the efficiency of the adopted arbitration scheme by allowing sufficient time for a number of iterations. PMM preserves 100% throughput under uniform traffic and fairness for best-effort traffic.
    Type: Application
    Filed: June 1, 2001
    Publication date: December 5, 2002
    Inventors: Eiji Oki, Roberto Rojas-Cessa, Jonathan Chao Hung-Hsiang
  • Publication number: 20020110135
    Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.
    Type: Application
    Filed: July 23, 2001
    Publication date: August 15, 2002
    Applicant: Polytechnic University
    Inventors: Eiji Oki, Hung-Hsiang Jonathan Chao, Roberto Rojas-Cessa
  • Patent number: RE42600
    Abstract: A pipeline-based matching scheduling approach for input-buffered switches relaxes the timing constraint for arbitration with matching schemes, such as CRRD and CMSD. In the new approach, arbitration may operate in a pipelined manner. Each sub-scheduler is allowed to take more than one time slot for its matching. Every time slot, one of them provides a matching result(s). The sub-scheduler can use a matching scheme such as CRRD and CMSD.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: August 9, 2011
    Assignee: Polytechnic University
    Inventors: Eiji Oki, Hung-Hsiang Jonathan Chao, Roberto Rojas-Cessa