Patents by Inventor Sahan Gamage

Sahan Gamage 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: 20190188050
    Abstract: Examples provide two-tiered scheduling within a cluster. A coarse-grained analysis is performed on a candidate set of hosts to select a host for a virtual computing instance based on optimization of at least one resource. A host is selected based on the analysis results. The identified virtual computing instance is placed on the selected host. A fine-grained analysis is performed on a set of communication graphs for a plurality of virtual computing instances to generate a set of penalty scores. A set of communicating virtual computing instances are selected based on the set of penalty scores. A first virtual computing instance from a first host is relocated to a second host to minimize a distance between the first virtual computing instance and a second virtual computing instance. Relocating the first virtual computing instance reduces at least one penalty score for the set of communicating virtual computing instances.
    Type: Application
    Filed: February 11, 2019
    Publication date: June 20, 2019
    Inventors: Po-An Tsai, Sahan Gamage, Rean Griffith
  • Patent number: 10320706
    Abstract: A management server and method for performing resource management operations in a distributed computer system utilizes interference scores for clients executing different workloads to create an interference affinity-type rule for at least some of the clients contending for a resource based on the interference scores for that resource. The interference affinity-type rule can then be used to recommend a target host computer to place a client.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: June 11, 2019
    Assignee: VMware, Inc.
    Inventors: Kalyan Saladi, Madhuri Yechuri, Xiaoyun Zhu, Sahan Gamage, Puneet Zaroo
  • Patent number: 10318323
    Abstract: A management server and method for performing resource management operations in a distributed computer system utilizes interference scores for clients executing different workloads, including a client to be placed in the distributed computer system, as utilization values of resources, which are assigned continuously variable weights to produce weighted resource utilization values. The weighted resource utilization values are used to generate overall selection scores for host computers of the distributed compute system, which are then used to recommend a target host computer among the host computers of the distributed computer system to place the client.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: June 11, 2019
    Assignee: VMware, Inc.
    Inventors: Xiaoyun Zhu, Madhuri Yechuri, Kalyan Saladi, Sahan Gamage, Puneet Zaroo
  • Patent number: 10241840
    Abstract: Examples provide two-tiered scheduling within a cluster. A coarse-grained analysis is performed on a candidate set of hosts to select a host for a virtual computing instance based on optimization of at least one resource. A host is selected based on the analysis results. The identified virtual computing instance is placed on the selected host. A fine-grained analysis is performed on a set of communication graphs for a plurality of virtual computing instances to generate a set of penalty scores. A set of communicating virtual computing instances are selected based on the set of penalty scores. A first virtual computing instance from a first host is relocated to a second host to minimize a distance between the first virtual computing instance and a second virtual computing instance. Relocating the first virtual computing instance reduces at least one penalty score for the set of communicating virtual computing instances.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: March 26, 2019
    Assignee: VMware, Inc.
    Inventors: Po-An Tsai, Sahan Gamage, Rean Griffith
  • Publication number: 20180095776
    Abstract: Examples provide two-tiered scheduling within a cluster. A coarse-grained analysis is performed on a candidate set of hosts to select a host for a virtual computing instance based on optimization of at least one resource. A host is selected based on the analysis results. The identified virtual computing instance is placed on the selected host. A fine-grained analysis is performed on a set of communication graphs for a plurality of virtual computing instances to generate a set of penalty scores. A set of communicating virtual computing instances are selected based on the set of penalty scores. A first virtual computing instance from a first host is relocated to a second host to minimize a distance between the first virtual computing instance and a second virtual computing instance. Relocating the first virtual computing instance reduces at least one penalty score for the set of communicating virtual computing instances.
    Type: Application
    Filed: September 30, 2016
    Publication date: April 5, 2018
    Inventors: Po-An Tsai, Sahan Gamage, Rean Griffith
  • Publication number: 20160380918
    Abstract: A management server and method for performing resource management operations in a distributed computer system utilizes interference scores for clients executing different workloads to create an interference affinity-type rule for at least some of the clients contending for a resource based on the interference scores for that resource. The interference affinity-type rule can then be used to recommend a target host computer to place a client.
    Type: Application
    Filed: June 29, 2015
    Publication date: December 29, 2016
    Applicant: VMware, Inc.
    Inventors: Kalyan Saladi, Madhuri Yechuri, Xiaoyun Zhu, Sahan Gamage, Puneet Zaroo
  • Publication number: 20160380907
    Abstract: A management server and method for performing resource management operations in a distributed computer system utilizes interference scores for clients executing different workloads, including a client to be placed in the distributed computer system, as utilization values of resources, which are assigned continuously variable weights to produce weighted resource utilization values. The weighted resource utilization values are used to generate overall selection scores for host computers of the distributed compute system, which are then used to recommend a target host computer among the host computers of the distributed computer system to place the client.
    Type: Application
    Filed: June 29, 2015
    Publication date: December 29, 2016
    Applicant: VMWARE, INC.
    Inventors: Xiaoyun Zhu, Madhuri Yechuri, Kalyan Saladi, Sahan Gamage, Puneet Zaroo
  • Patent number: 8982724
    Abstract: A system and method are provided for implementing a peak-to-average power ratio (PAPR) reduction scheme for Orthogonal Frequency-Division Multiple Access (OFDMA) modulation. A unique PAPR reduction scheme for OFDMA modulation for systems operated according to a DOCSIS standard achieves results similar to those attributable to tone reservation schemes in a manner that does not negatively affect an amount of available data capacity, particularly in implementations with limited numbers of subcarriers. The disclosed systems and methods are particularly adaptable to next generation cable gateways and/or next generation cable modems. These next generation cable gateways and/or cable modems may find particular utility in advanced hybrid fiber/coaxial cable systems. The adaptable cable gateways/modems may include a cable gateway system-on-chip (SOC) configuration. The disclosed schemes may be applicable to OFDM modulation. For OFDM, however, the known tone reservation algorithms also may be employed.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: March 17, 2015
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8929471
    Abstract: Methods and systems to mitigate impulse interference in an OFDM QAM signal. A per-symbol noise measure, or quality measure (QM) is computed for a symbol k as a MSE of distances between carriers in the symbol and points of corresponding QAM constellations. MSE(k) is averaged over multiple symbols to compute a background signal QM, AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a moderate amount, symbol k may be moderately affected by impulse interference, and per-carrier SNR estimates are downgraded for all data carriers in symbol k, prior to LLR computation. SNR downgrading may be linear or step-wise based on an extent to which MSE(k) exceeds AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a significant amount, symbol k may be significantly affected by impulse interference, and LLRs may be set to indicate that all data carriers are erased in symbol k.
    Type: Grant
    Filed: October 26, 2012
    Date of Patent: January 6, 2015
    Assignee: Intel Corporation
    Inventors: Thushara Hewavithana, Bernard Arambepola, Sahan Gamage
  • Patent number: 8908810
    Abstract: A system and method are provided for implementing a soft Reed-Solomon (RS) decoding scheme, technique or algorithm to improve physical layer performance in cable modems and cable gateways. The algorithm is implemented in a forward error correction (FEC) module connected to a QAM demodulator. The RS decoding scheme is implemented without significantly complicating hardware or processing overhead. The soft Reed-Solomon (RS) decoding scheme extracts candidate RS symbols and their Log Likelihood Ratios (LLRs) from QAM symbols. The set of highest probable candidate blocks are then chosen and these are decoded using a variant of the Chase algorithm until a valid codeword is detected at the decoder output.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: December 9, 2014
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Murat Badem, Parveen K. Shukla, Sahan Gamage, Thushara Hewavithana, Naor Goldman
  • Patent number: 8817195
    Abstract: An embodiment of the present invention provides a method for digital television demodulation, comprising using adjacent-channel power dependent automatic gain control (AGC) for the digital television demodulation, wherein an AGC technique takes into account a total power as well as power of adjacent channels to control gain of a gain control amplifier.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: August 26, 2014
    Assignee: Intel Corporation
    Inventors: Parveen K. Shukla, Bernard Arambepola, Thushara Hewavithana, Sahan Gamage
  • Publication number: 20140185657
    Abstract: A system and method are provided for implementing a soft Reed-Solomon (RS) decoding scheme, technique or algorithm to improve physical layer performance in cable modems and cable gateways. At 1024-QAM, a receiver is provided in which a signal to noise ratio is reduced by at least about 1 dB relaxing design considerations and specifications for other components in the system including for the tuner. A soft-RS-symbol generation scheme is provided to enable soft-input RC decoding in a forward error correction (FEC) module connected to a QAM demodulator. The RS decoding scheme is implemented without significantly complicating hardware or processing overhead. A typical receiver hardware requirement in an FEC module to implement the disclosed scheme may be comparatively modest, e.g., on an order of approximately 50K gates.
    Type: Application
    Filed: December 27, 2012
    Publication date: July 3, 2014
    Inventors: Bernard Arambepola, Murat Badem, Parveen K. Shukla, Sahan Gamage, Thushara Hewavithana, Naor Goldman
  • Publication number: 20140169188
    Abstract: A system and method are provided for implementing a peak-to-average power ratio (PAPR) reduction scheme for Orthogonal Frequency-Division Multiple Access (OFDMA) modulation. A unique PAPR reduction scheme for OFDMA modulation for systems operated according to a DOCSIS standard achieves results similar to those attributable to tone reservation schemes in a manner that does not negatively affect an amount of available data capacity, particularly in implementations with limited numbers of subcarriers. The disclosed systems and methods are particularly adaptable to next generation cable gateways and/or next generation cable modems. These next generation cable gateways and/or cable modems may find particular utility in advanced hybrid fiber/coaxial cable systems. The adaptable cable gateways/modems may include a cable gateway system-on-chip (SOC) configuration. The disclosed schemes may be applicable to OFDM modulation. For OFDM, however, the known tone reservation algorithms also may be employed.
    Type: Application
    Filed: December 17, 2012
    Publication date: June 19, 2014
    Inventors: Bernard Arambepola, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Publication number: 20140119420
    Abstract: Methods and systems to mitigate impulse interference in an OFDM QAM signal. A per-symbol noise measure, or quality measure (QM) is computed for a symbol k as a MSE of distances between carriers in the symbol and points of corresponding QAM constellations. MSE(k) is averaged over multiple symbols to compute a background signal QM, AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a moderate amount, symbol k may be moderately affected by impulse interference, and per-carrier SNR estimates are downgraded for all data carriers in symbol k, prior to LLR computation. SNR downgrading may be linear or step-wise based on an extent to which MSE(k) exceeds AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a significant amount, symbol k may be significantly affected by impulse interference, and LLRs may be set to indicate that all data carriers are erased in symbol k.
    Type: Application
    Filed: October 26, 2012
    Publication date: May 1, 2014
    Inventors: Thushara Hewavithana, Bernard Arambepola, Sahan Gamage
  • Publication number: 20140036157
    Abstract: An embodiment of the present invention provides a method for digital television demodulation, comprising using adjacent-channel power dependent automatic gain control (AGC) for the digital television demodulation, wherein an AGC technique takes into account a total power as well as power of adjacent channels to control gain of a gain control amplifier.
    Type: Application
    Filed: October 7, 2013
    Publication date: February 6, 2014
    Inventors: Parveen K. Shukla, Bernard Arambepola, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8532113
    Abstract: Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
    Type: Grant
    Filed: September 26, 2011
    Date of Patent: September 10, 2013
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Tony Cole, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8392802
    Abstract: Methods and systems to identify a codeword associated with samples of a signal from spectral content of the samples, and to estimate a frequency offset from the spectral contents. The samples may correspond to a physical layer header of a data frame. Modulation may be removed from the samples in accordance with each of a plurality of modulation sequences, each sequence associated with a corresponding codeword. Power levels in spectral contents of the modulation-removed samples are examined to identify a peak power level indicative of a match between a modulation sequence and the samples. The corresponding codeword is identified as being associated with the header, and transmission parameters associated with the identified codeword are used to decode a corresponding frame. An estimated frequency offset may be determined from a frequency associated with the peak power level.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: March 5, 2013
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Vinesh Bhunjun, Thushara Hewavithana, Parveen K. Shukla, Sahan Gamage
  • Publication number: 20120014372
    Abstract: Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
    Type: Application
    Filed: September 26, 2011
    Publication date: January 19, 2012
    Inventors: Bernard Arambepola, Tony Cole, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8059687
    Abstract: Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: November 15, 2011
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Tony Cole, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Publication number: 20110154148
    Abstract: Methods and systems to identify a codeword associated with samples of a signal from spectral content of the samples, and to estimate a frequency offset from the spectral contents. The samples may correspond to a physical layer header of a data frame. Modulation may be removed from the samples in accordance with each of a plurality of modulation sequences, each sequence associated with a corresponding codeword. Power levels in spectral contents of the modulation-removed samples are examined to identify a peak power level indicative of a match between a modulation sequence and the samples. The corresponding codeword is identified as being associated with the header, and transmission parameters associated with the identified codeword are used to decode a corresponding frame. An estimated frequency offset may be determined from a frequency associated with the peak power level.
    Type: Application
    Filed: December 23, 2009
    Publication date: June 23, 2011
    Inventors: Bernard Arambepola, Vinesh Bhunjun, Thushara Hewavithana, Parveen K. Shukla, Sahan Gamage