Patents by Inventor Inwoong Kim

Inwoong Kim 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: 10097376
    Abstract: In one or more embodiments, one or more systems of a physical optical network that may implement and/or manage a virtual optical network (VON) that interconnects multiple data centers. Virtual nodes based the multiple data centers to be interconnected may be determined, and each of the virtual nodes may be mapped to at least two physical nodes of the physical optical network. Virtual links for pairs of the virtual nodes may be determined, and each virtual link may be mapped to at least one optical network connection of the physical optical network. At least one of a physical node impairment and an optical network connection impairment that is associated with a first physical node implementing a first virtual node may be detected, and the first virtual node may be implemented via a second physical node.
    Type: Grant
    Filed: February 2, 2017
    Date of Patent: October 9, 2018
    Assignee: Fujitsu Limited
    Inventors: Xi Wang, Paparao Palacharla, Qiong Zhang, Inwoong Kim, Tadashi Ikeuchi
  • Patent number: 10090961
    Abstract: A method and system for multi-channel optical XPM compensation may include a DCM to improve performance of a feed-forward control loop in an optical path in an optical network. Additionally, various spectral overlap schemes may be used with multi-channel WDM optical signals using XPM compensators in parallel, such as at a ROADM node. Polarization diversity may also be supported for XPM compensation including a DCM.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: October 2, 2018
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Olga Vassilieva, Takeshi Hoshida, Paparao Palacharla, Tadashi Ikeuchi
  • Patent number: 10063317
    Abstract: A method and system for selective and per-node XPM compensation may separate wavelengths into short traveling wavelengths (STW) and long traveling wavelengths (LTW) based on transmission distance over their respective optical paths. XPM compensation at ROADM nodes may be selectively performed for the LTW, while the STW may be passed through without XPM compensation, among other functionality at the ROADM nodes.
    Type: Grant
    Filed: August 25, 2017
    Date of Patent: August 28, 2018
    Assignee: Fujitsu Limited
    Inventors: Olga Vassilieva, Inwoong Kim, Tadashi Ikeuchi
  • Publication number: 20180227243
    Abstract: Systems and methods for performing distributed virtual network embedding are disclosed. A resource orchestrator may receive a virtual network request specifying a set of virtual nodes, a set of virtual links, each connecting two virtual nodes in a mesh topology, and resource requirements for some virtual nodes. The orchestrator may partition the virtual network request into multiple sub-requests, each specifying a linear topology for a subset of the virtual nodes and links within the mesh topology. The sub-requests may collectively include all virtual links within the mesh topology with no overlapping links. Resource orchestrators may collaborate to compute, independently for each sub-request, a respective chaining solution in which each virtual node is mapped to a physical node having resources sufficient to implementing the virtual node. A resource orchestrator may combine the respective chaining solutions for each of the sub-requests to generate a mapping solution for the virtual network request.
    Type: Application
    Filed: February 3, 2017
    Publication date: August 9, 2018
    Inventors: Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi, Xi Wang, Inwoong Kim
  • Patent number: 10038496
    Abstract: Methods and systems for determining optical network utilization efficiency include generating a random demand set and calculating a demand fill ratio (DFR) based on the random demand set. The random demand set includes network demands for a given optical network topology that provide 100% of the wavelength slots in the optical network topology. The DFR may be calculated using different wavelength assignment algorithms, such as a first fit wavelength assignment algorithm, from the randomly generated demands in the random demand set. The DFR may be calculated without and with wavelength conversion nodes.
    Type: Grant
    Filed: March 14, 2017
    Date of Patent: July 31, 2018
    Assignee: Fujitsu Limited
    Inventors: Xi Wang, Inwoong Kim, Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20180167142
    Abstract: A method and system for selective and per-node XPM compensation may separate wavelengths into short traveling wavelengths (STW) and long traveling wavelengths (LTW) based on transmission distance over their respective optical paths. XPM compensation at ROADM nodes may be selectively performed for the LTW, while the STW may be passed through without XPM compensation, among other functionality at the ROADM nodes.
    Type: Application
    Filed: August 25, 2017
    Publication date: June 14, 2018
    Inventors: Olga Vassilieva, Inwoong Kim, Tadashi Ikeuchi
  • Publication number: 20180167157
    Abstract: A method and system for multi-channel optical XPM compensation may include a DCM to improve performance of a feed-forward control loop in an optical path in an optical network. Additionally, various spectral overlap schemes may be used with multi-channel WDM optical signals using XPM compensators in parallel, such as at a ROADM node. Polarization diversity may also be supported for XPM compensation including a DCM.
    Type: Application
    Filed: December 8, 2016
    Publication date: June 14, 2018
    Inventors: Inwoong Kim, Olga Vassilieva, Takeshi Hoshida, Paparao Palacharla, Tadashi Ikeuchi
  • Patent number: 9998563
    Abstract: Systems and methods for performing vertex-centric service function chaining in multi-domain networks are disclosed. A resource orchestration framework of a multi-domain network may include vertices representing physical nodes and edges representing physical links in the network. A sole resource orchestrator (in a centralized system) or multiple resource orchestrators (each associated with a respective domain in a distributed system) may coordinate execution of a common compute function on multiple vertices to identify candidate service function chain solutions to a service function chain request. The request may specify a fixed-ordered chain or a flexible-ordered chain. The compute function may, during each of multiple supersteps, determine whether a partially mapped chain can be extended on a given vertex, send a controller message to a neighbor vertex with which it has a qualified link, or return a completed chain, which may be selected for execution, dependent on applicable policies.
    Type: Grant
    Filed: June 7, 2016
    Date of Patent: June 12, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Qiong Zhang, Paparao Palacharla, Xi Wang, Inwoong Kim, Tadashi Ikeuchi
  • Publication number: 20180159629
    Abstract: Methods and systems enable amplifying optical signals using a Bragg reflection waveguide (BRW) having second order optical nonlinearity to generate an optical pump by injection locking. The BRW may also be used for parametric amplification of optical signals using the optical pump. Feedback phase-power control may be performed to maximize output power.
    Type: Application
    Filed: January 19, 2018
    Publication date: June 7, 2018
    Inventors: Inwoong Kim, Youichi Akasaka, Jeng-Yuan Yang, Motoyoshi Sekiya
  • Patent number: 9973383
    Abstract: Methods and systems enable optimized placement of wavelength shifters in optical networks. The wavelength shifters may include O-E-O regenerators for a single wavelength and all optical wavelength shifters for one or more wavelengths. An auxiliary graph is used to represent various links in a provisioned optical path. By applying cost values to each of the links, different types of optimizations for network resource utilization may be realized.
    Type: Grant
    Filed: October 12, 2015
    Date of Patent: May 15, 2018
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Xi Wang, Paparao Palacharla, Tadashi Ikeuchi
  • Patent number: 9967054
    Abstract: Methods and systems for optimizing the transmission of superchannels with different modulation formats may include pre-calculating different guardband (GB) values between superchannels and sets of power values for subcarriers to implement subcarrier power pre-emphasis (SPP). When a request for an optical path is received at a network management system, the spectral allocation of each superchannel, including a GB, is determined according to pre-specified rules based on co-propagation of the superchannels with different modulation formats.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: May 8, 2018
    Assignee: Fujitsu Limited
    Inventors: Olga Vassilieva, Inwoong Kim, Tadashi Ikeuchi
  • Patent number: 9967053
    Abstract: Methods and systems are provided for determining a shortest minimum regeneration path in an optical network. The method includes creating a virtual node at a source node, the source node communicatively coupled to a destination node through a plurality of nodes and links. The method includes traversing the virtual nodes, wherein traversing the virtual nodes comprises selecting an unvisited virtual node at a node; identifying a candidate virtual node from the unvisited virtual node; determining whether the candidate virtual node exceeds a maximum permitted weight; determining whether the candidate virtual node violates a shortest minimum regeneration path condition; and creating the new virtual node from the candidate virtual node if the candidate virtual node does not exceed the maximum permitted weight and if the candidate virtual node does not violate the shortest minimum regeneration path condition.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: May 8, 2018
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Xi Wang, Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi
  • Patent number: 9941994
    Abstract: Methods and systems are provided for wavelength shift elimination during spectral inversion in optical networks. The method includes receiving an input optical signal, and generating a combined optical signal by combining, by Bragg scattering, the input optical signal having an input wavelength with a first pump signal having a first wavelength. The method further includes converting the combined optical signal into an output optical signal, by phase-conjugation, using a second pump signal having a second wavelength. The output optical signal has the same wavelength as the input optical signal.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: April 10, 2018
    Assignee: Fujitsu Limited
    Inventors: Kevin Croussore, Inwoong Kim, Olga I. Vassilieva, Takao Naito
  • Patent number: 9923634
    Abstract: Methods and systems enable amplifying optical signals using a Bragg reflection waveguide (BRW) having second order optical nonlinearity to generate an optical pump by injection locking. The BRW may also be used for parametric amplification of optical signals using the optical pump. Feedback phase-power control may be performed to maximize output power.
    Type: Grant
    Filed: September 23, 2015
    Date of Patent: March 20, 2018
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Youichi Akasaka, Jeng-Yuan Yang, Motoyoshi Sekiya
  • Patent number: 9912435
    Abstract: Methods and systems may estimate nonlinear penalties for optical paths using spectral inversion in optical transport networks. Certain values of nonlinear transfer functions for nonlinear penalty estimation may be pre-calculated for optical paths between given nodes. When an optical path computation for using spectral inversion between a given source node and a given destination node is desired, the pre-calculated values may be concatenated for improved computational efficiency.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: March 6, 2018
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Olga Vassilieva, Paparao Palacharla, Motoyoshi Sekiya
  • Patent number: 9843410
    Abstract: Methods and systems for amplifying optical signals include generating idler signals for input signals using an optical pump at a first Bragg reflection waveguide (BRW) having second order optical nonlinearity. Phase and amplitude regulation is performed using the output from the first BRW. Optical power monitoring of the input signals may be used for power equalization. The phase-sensitive amplified signal is generated at a second BRW using the optical pump. Optical power monitoring of the input signals may be used for power equalization.
    Type: Grant
    Filed: November 18, 2015
    Date of Patent: December 12, 2017
    Assignee: Fujitsu Limited
    Inventors: Jeng-Yuan Yang, Inwoong Kim, Youichi Akasaka, Motoyoshi Sekiya
  • Patent number: 9838253
    Abstract: Object-oriented network virtualization may involve creating and operating virtual network objects (VNO) using a software-programmed networking operating system (SPN OS). A VNO may be a complete representation of a virtual network service provided under the SPN OS. A VNO may have a unique identity and properties, along with an internal set of methods for executing functionality encapsulated by the VNO. A VNO may exhibit persistence and autonomous control to enable improved virtual network services.
    Type: Grant
    Filed: December 18, 2014
    Date of Patent: December 5, 2017
    Assignee: Fujitsu Limited
    Inventors: Xi Wang, Motoyoshi Sekiya, Paparao Palacharla, Qiong Zhang, Inwoong Kim
  • Patent number: 9838123
    Abstract: Methods and systems may mitigate nonlinear noise (NLN) penalties for optical paths using spectral inversion in optical transport networks. Using a tunable dispersion compensator with an optical amplifier at each span in an optical path, the dispersion along the optical path may be modified to a normalized dispersion for each span. In this manner, the dispersion associated with NLN accumulation may be balanced by NLN compensation to reduce overall NLN levels for the optical path.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: December 5, 2017
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Olga Vassilieva, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20170346719
    Abstract: Methods and systems are provided for determining a shortest path with a constraint in an optical network. The method includes identifying a permitted number of events defined by the constraint. The method further includes creating virtual nodes for each node in the optical network, the virtual nodes corresponding with the permitted number of events. The method also includes traversing the virtual nodes from a source node to a destination node with a shortest path algorithm, wherein traversing the virtual nodes comprises creating virtual links between the virtual nodes when the constraint is not violated, the virtual link corresponding with a physical link; and identifying a shortest path between the source node and the destination node from the virtual links, the shortest path not violating the constraint.
    Type: Application
    Filed: May 31, 2016
    Publication date: November 30, 2017
    Inventors: Inwoong Kim, Xi Wang, Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20170346594
    Abstract: Methods and systems for optimizing the transmission of superchannels with different modulation formats may include pre-calculating different guardband (GB) values between superchannels and sets of power values for subcarriers to implement subcarrier power pre-emphasis (SPP). When a request for an optical path is received at a network management system, the spectral allocation of each superchannel, including a GB, is determined according to pre-specified rules based on co-propagation of the superchannels with different modulation formats.
    Type: Application
    Filed: December 22, 2016
    Publication date: November 30, 2017
    Inventors: Olga Vassilieva, Inwoong Kim, Tadashi Ikeuchi