Patents by Inventor Shinsuke Fujisawa

Shinsuke Fujisawa 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: 10848262
    Abstract: In an optical communication network using the wavelength division multiplexing system, the accommodation efficiency for the optical paths decreases, and it becomes difficult to use the optical communication network efficiently, if the optical frequency slots are used concentrically in a specific optical fiber; therefore, an optical path design apparatus according to an exemplary aspect of the present invention includes route candidate selection means for searching for a route of an optical path to accommodate a communication demand and selecting a plurality of route candidates; optical path candidate selection means for selecting a plurality of optical path candidates by allocating an optical frequency band required to accommodate the optical path to each of optical fibers on the plurality of route candidates; and optical path determination means for determining the optical path from among the plurality of optical path candidates based on an optical frequency band utilization rate in the optical fibers.
    Type: Grant
    Filed: September 20, 2017
    Date of Patent: November 24, 2020
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Akio Tajima
  • Publication number: 20200344533
    Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.
    Type: Application
    Filed: July 9, 2020
    Publication date: October 29, 2020
    Applicant: NEC CORPORATION
    Inventors: Hitoshi TAKESHITA, Shinsuke FUJISAWA, Tomoyuki HINO, Akio TAJIMA
  • Publication number: 20200313765
    Abstract: If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.
    Type: Application
    Filed: June 17, 2020
    Publication date: October 1, 2020
    Applicant: NEC Corporation
    Inventors: Tomoyuki HINO, Akio TAJIMA, Hitoshi TAKESHITA, Shinsuke FUJISAWA
  • Patent number: 10750259
    Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.
    Type: Grant
    Filed: June 18, 2019
    Date of Patent: August 18, 2020
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
  • Patent number: 10715249
    Abstract: If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: July 14, 2020
    Assignee: NEC CORPORATION
    Inventors: Tomoyuki Hino, Akio Tajima, Hitoshi Takeshita, Shinsuke Fujisawa
  • Publication number: 20200136743
    Abstract: It is difficult in the elastic optical network to achieve a balance between the improvement in the frequency utilization efficiency and the increase in the probability of opening an optical path; therefore, an optical path controller according to an exemplary aspect of the present invention includes route selection means for searching for a route candidate being a candidate for a route to accommodate an optical path, and selecting a best possible route with a minimum route selection index serving as an index for route search; use rate collecting means for collecting a use rate serving as an index to indicate a usage condition of an optical frequency band in an optical fiber transmission line included in the route candidate; and route selection index judgment means for determining the route selection index based on the use rate.
    Type: Application
    Filed: July 6, 2017
    Publication date: April 30, 2020
    Applicant: NEC Corporation
    Inventors: Shinsuke FUJISAWA, Akio TAJIMA, Hitoshi TAKESHITA
  • Patent number: 10542335
    Abstract: In the elastic optical network, there has been the problem that processing steps increase that are required to re-optimize client signals to be concentrated; therefore, an optical network controller according to an exemplary aspect of the present invention includes reallocation detection means for monitoring an operation status of at least one of an optical communication channel and an optical node device that constitute an optical network, and determining, based on the operation status, whether or not to reallocate a client signal accommodated in an optical path set in the optical network; design-candidate exclusion means for designating, as a design exclusion object, at least one of the optical communication channel and the optical node device that are associated with an optical path targeted for reallocation that accommodates the client signal that the reallocation detection means has determined to reallocate; optical path design means for determining an alternative route for the optical path targeted for
    Type: Grant
    Filed: February 8, 2017
    Date of Patent: January 21, 2020
    Assignee: NEC CORPORATION
    Inventors: Shinsuke Fujisawa, Akio Tajima, Hitoshi Takeshita, Tomoyuki Hino
  • Patent number: 10447419
    Abstract: In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for dividing an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, and setting a plurality of optical frequency regions; and an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: October 15, 2019
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
  • Publication number: 20190306597
    Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.
    Type: Application
    Filed: June 18, 2019
    Publication date: October 3, 2019
    Applicant: NEC CORPORATION
    Inventors: Hitoshi TAKESHITA, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
  • Publication number: 20190260474
    Abstract: In an optical communication network using the wavelength division multiplexing system, the accommodation efficiency for the optical paths decreases, and it becomes difficult to use the optical communication network efficiently, if the optical frequency slots are used concentrically in a specific optical fiber; therefore, an optical path design apparatus according to an exemplary aspect of the present invention includes route candidate selection means for searching for a route of an optical path to accommodate a communication demand and selecting a plurality of route candidates; optical path candidate selection means for selecting a plurality of optical path candidates by allocating an optical frequency band required to accommodate the optical path to each of optical fibers on the plurality of route candidates; and optical path determination means for determining the optical path from among the plurality of optical path candidates based on an optical frequency band utilization rate in the optical fibers.
    Type: Application
    Filed: September 20, 2017
    Publication date: August 22, 2019
    Applicant: NEC Corporation
    Inventors: Hitoshi TAKESHITA, Shinsuke FUJISAWA, Akio TAJIMA
  • Patent number: 10382135
    Abstract: In an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid, it is difficult to improve the usage efficiency of an optical frequency band owing to the occurrence of fragmentation of the optical frequency band; therefore, an optical network controller according to an exemplary aspect of the present invention includes an optical frequency region setting means for setting a plurality of optical frequency regions in an optical frequency band used in an optical network based on a dense wavelength division multiplexing system using a flexible frequency grid; an optical path setting means for setting optical paths having a common attribute in at least one of the plurality of optical frequency regions; and an optical frequency region control means for changing an optical frequency width of the optical frequency region, and instructing the optical frequency region setting means to reconfigure, as the plurality of optical frequency regions, a plurality of optical frequ
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: August 13, 2019
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
  • Patent number: 10375460
    Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.
    Type: Grant
    Filed: February 20, 2017
    Date of Patent: August 6, 2019
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Tomoyuki Hino, Akio Tajima
  • Publication number: 20190238451
    Abstract: An optical network control device includes: a path setting unit that sets, based on topology information including a connection relationship among a plurality of nodes and a first route selection index value of routes each connecting the plurality of nodes, a first path for a route having the first route selection index value being minimum from among route candidates linking a start point node and an end point node of a requested traffic; a topology information modification unit that calculates a second route selection index value acquired by increasing the first route selection index value of the route that accommodates the first path; and a path selection unit that selects a second path for a route having the second route selection index value being minimum from among the route candidates.
    Type: Application
    Filed: October 4, 2017
    Publication date: August 1, 2019
    Applicant: NEC Corporation
    Inventors: Shinsuke FUJISAWA, Hitoshi TAKESHITA, Akio TAJIMA
  • Patent number: 10230487
    Abstract: It is made possible to accommodate a plurality of services and transmit each of the accommodated services to a corresponding transmission device. An optical transmitter according to an exemplary aspect of the present invention includes sub-carrier adjusting means for outputting sub-carriers to a plurality of output ports according to a control signal; encoding processing means for mapping client data on a plurality of output lanes according to the control signal; a plurality of modulation means for modulating the sub-carriers inputted through the output ports by client data inputted through the output lanes and outputting modulated signals; and control means for generating and outputting the control signal based on transmission information.
    Type: Grant
    Filed: March 11, 2015
    Date of Patent: March 12, 2019
    Assignee: NEC CORPORATION
    Inventors: Tomoyuki Hino, Shinsuke Fujisawa, Hitoshi Takeshita, Akio Tajima
  • Patent number: 10211923
    Abstract: In an optical network system based on a wavelength division multiplexing system using a flexible frequency grid, with the diversification of optical modulation methods, the management burden on an optical network management device increases, and its control becomes complicated; therefore, an optical network system according to an exemplary aspect of the present invention includes an optical network management device configured to receive a traffic demand, design an optical path capable of accommodating the traffic demand, and create optical path design information of a design result; and an optical node device configured to be used for creating the optical path, wherein the optical node device calculates an allocable bandwidth from the optical path design information and optical node device information on a configuration of the optical node device, and the allocable bandwidth is an optical frequency bandwidth of a generable optical path that the optical node device is capable of generating, and the optical ne
    Type: Grant
    Filed: November 11, 2015
    Date of Patent: February 19, 2019
    Assignee: NEC Corporation
    Inventors: Hitoshi Takeshita, Tomoyuki Hino, Shinsuke Fujisawa, Akio Tajima
  • Publication number: 20190037289
    Abstract: It is difficult to improve the usage efficiency of an optical communication network due to the passband narrowing effect in a wavelength selection process in an optical communication network using a wavelength division multiplexing system; therefore, an optical network management apparatus according to an exemplary aspect of the present invention includes wavelength selection information generating means for generating wavelength selection information on a wavelength selection process through which an optical path accommodating an information signal goes, with respect to each optical path; and wavelength selection information notifying means for notifying an optical node device through which the optical path goes of the wavelength selection information.
    Type: Application
    Filed: February 20, 2017
    Publication date: January 31, 2019
    Applicant: NEC CORPORATION
    Inventors: Hitoshi TAKESHITA, Shinsuke FUJISAWA, Tomoyuki HINO, Akio TAJIMA
  • Publication number: 20190037288
    Abstract: In the elastic optical network, there has been the problem that processing steps increase that are required to re-optimize client signals to be concentrated; therefore, an optical network controller according to an exemplary aspect of the present invention includes reallocation detection means for monitoring an operation status of at least one of an optical communication channel and an optical node device that constitute an optical network, and determining, based on the operation status, whether or not to reallocate a client signal accommodated in an optical path set in the optical network; design-candidate exclusion means for designating, as a design exclusion object, at least one of the optical communication channel and the optical node device that are associated with an optical path targeted for reallocation that accommodates the client signal that the reallocation detection means has determined to reallocate; optical path design means for determining an alternative route for the optical path targeted for
    Type: Application
    Filed: February 8, 2017
    Publication date: January 31, 2019
    Applicant: NEC CORPORATION
    Inventors: Shinsuke FUJISAWA, Akio TAJIMA, Hitoshi TAKESHITA, Tomoyuki HINO
  • Patent number: 10193651
    Abstract: It is difficult to improve the wavelength-band utilization rate of an optical network as a whole while operating the optical network stably; and therefore, an optical network controller according to an exemplary aspect of the present invention includes optical wavelength region setting means for setting a wavelength region in an optical transmission line between a plurality of optical nodes composing an optical network using wavelength division multiplexing system dividing the wavelength region into consecutive regions of a first wavelength region and a second wavelength region; optical path setting means for setting a first optical path in the first wavelength region and a second optical path in the second wavelength region, the second optical path differing from the first optical path in a route; and control unit for instructing the plurality of optical nodes on a central wavelength and a usable band of signal light for the optical node to transmit based on a setting by the optical path setting means.
    Type: Grant
    Filed: February 16, 2015
    Date of Patent: January 29, 2019
    Assignee: NEC CORPORATION
    Inventors: Hitoshi Takeshita, Shinsuke Fujisawa, Ryuichi Ikematsu, Akio Tajima, Tomoyuki Hino
  • Patent number: 9979468
    Abstract: It is difficult in an optical network to achieve fault recovery in case of multiple failures without decreasing the usage efficiency of the optical network; therefore, an optical communication system according to an exemplary aspect of the present invention includes an optical network management device including an optical path setting means for setting, to a physical route differing from each other, a backup path corresponding to each of a plurality of active paths on an identical physical route, and a failure-case optical path setting means for setting a failure-case backup path with a compressed band of the backup path, to a physical route without a failure in a case where failures arising on more than one physical route among the physical routes; and an optical node device including an optical transceiver means for transmitting and receiving optical signals using failure-case backup path information resulting from setting by the failure-case optical path setting means.
    Type: Grant
    Filed: September 15, 2015
    Date of Patent: May 22, 2018
    Assignee: NEC Corporation
    Inventors: Shinsuke Fujisawa, Hitoshi Takeshita, Tomoyuki Hino, Akio Tajima
  • Publication number: 20180083698
    Abstract: If wavelength defragmentation is performed during the operation of an optical network, an instantaneous interruption of a network arises; consequently, data are lost; therefore, an optical network control method according to an exemplary aspect of the present invention includes monitoring a data volume of a client signal to be transmitted using a plurality of optical subcarriers; and performing synchronously, depending on a variation in the data volume, an optical subcarrier changing process of changing an active optical subcarrier, of the plurality of optical subcarriers, to be used for transmitting the client signal, and a remapping process of remapping the client signal onto an active optical subcarrier after having been changed.
    Type: Application
    Filed: March 18, 2016
    Publication date: March 22, 2018
    Applicant: NEC Corporation
    Inventors: Tomoyuki HINO, Akio TAJIMA, Hitoshi TAKESHITA, Shinsuke FUJISAWA