Patents by Inventor Masahiko Mizutani
Masahiko Mizutani 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).
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Patent number: 9407389Abstract: In an extensive distribution system with no delay guarantee network used as a relay network, an influence of a fluctuation of a communication delay time is avoided to conduct a high-precision time synchronization. First and second delay control devices installed in junctions between communication networks and a relay network, respectively, have functions of retaining first and second time information, and setting a first relay network passing time of a first communication signal directed from a time dissemination device toward a time receiving device through a relay network, and a second relay network passing time of a second communication signal directed from the time receiving device toward the time dissemination device, respectively. In measurement of communication delay time of the first communication network and the second communication network prior to time synchronization, the first and second relay network passing times are unified in advance to exclude uncertainty of the communication time.Type: GrantFiled: August 7, 2014Date of Patent: August 2, 2016Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Hiroaki Nakazawa, Yoshihiro Ashi, Daiji Mitsunaga, Hideyuki Nakanishi
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Patent number: 9379877Abstract: A transmission device uses transmission delay time of reciprocation with the terminal and time information of the transmission device to create a correction value of time information of the terminal and transmits it to the terminal. The terminal includes expected arrival time information based on the time information of the terminal and the correction value received from the transmission device in a frame transmitted to the transmission device. The transmission device compares reception time of the frame with the expected arrival time information in the frame. If they match, the time information of the terminal synchronizes with the time information of the transmission device. If they do not match, the transmission device transmits a new correction value to the terminal. The terminal transmits a frame including expected arrival time information using the new correction value to the transmission device.Type: GrantFiled: November 16, 2012Date of Patent: June 28, 2016Assignee: HITACHI, LTD.Inventors: Masahiko Mizutani, Yoshihiro Ashi
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Patent number: 9350746Abstract: A transmission network system includes a network terminating device connected to a user terminal and an authentication information device connected to the network terminating device through a transmission network. The transmission network is connected to a reference clock that holds a reference time. The network terminating device includes a terminating internal clock that synchronizes with the reference clock, when receiving a first frame from the user terminal, generates a second frame including a time outputted from the terminating internal clock as a request time on the basis of the first frame, and transmits the second frame to the authentication information device. The authentication information device generates time authentication information based on the request time included in the received second frame, generates a third frame including the generated time authentication information, and transmits the third frame to the transmission network.Type: GrantFiled: January 23, 2014Date of Patent: May 24, 2016Assignee: Hitachi, Ltd.Inventors: Shinya Fujioka, Yoshihiro Ashi, Masahiko Mizutani
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Patent number: 9166874Abstract: A redundant path configuration method and a control method are disclosed. An intercommunication path for mutually transmitting and receiving a signal is provided among the BHEs each of which is a top of a tree. When failures occur in an active system path in certain AE, a standby system path (BHE) relays communication between the AE and the (active system) BHE so as to secure continuity of communication. The intercommunication path through which a data signal does not flow in a normal operation is used as a traffic accommodation path in an emergency among the BHEs. By setting a bypass between the tops of the trees, when a failure occurs in one tree, a signal is transferred from the active system BHE to the standby system path in which another BHE is a top to build a sub-tree bypassing the failure point and to secure a communication path.Type: GrantFiled: October 28, 2011Date of Patent: October 20, 2015Assignee: HITACHI, LTD.Inventor: Masahiko Mizutani
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Publication number: 20150103643Abstract: A transmission network is comprised of a network management system for collectively managing and controlling a plurality of transmission devices coupled mutually through transmission routes and the transmission network as well. The network management system includes a plane management table adapted to manage transmission planes defined as a set of paths in the transmission network, and the plane management table has the function to set and manage a transmission plane (working plane) applied during normal operation and besides, a single or a plurality of transmission planes (protection planes) applicable in the event of occurrence of a fault in the transmission network. Then, when a fault occurs in the transmission network, the network management system changes the applied plane to a suitable transmission plane.Type: ApplicationFiled: December 18, 2014Publication date: April 16, 2015Applicant: Hitachi, Ltd.Inventors: SHINYA FUJIOKA, Yoshihiro ASHI, Masahiko MIZUTANI, Hideki ENDO
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Publication number: 20150085852Abstract: In an extensive distribution system with no delay guarantee network used as a relay network, an influence of a fluctuation of a communication delay time is avoided to conduct a high-precision time synchronization. First and second delay control devices installed in junctions between communication networks and a relay network, respectively, have functions of retaining first and second time information, and setting a first relay network passing time of a first communication signal directed from a time dissemination device toward a time receiving device through a relay network, and a second relay network passing time of a second communication signal directed from the time receiving device toward the time dissemination device, respectively. In measurement of communication delay time of the first communication network and the second communication network prior to time synchronization, the first and second relay network passing times are unified in advance to exclude uncertainty of the communication time.Type: ApplicationFiled: August 7, 2014Publication date: March 26, 2015Applicant: HITACHI, LTD.Inventors: Masahiko MIZUTANI, Hiroaki NAKAZAWA, Yoshihiro ASHI, Daiji MITSUNAGA, Hideyuki NAKANISHI
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Patent number: 8864231Abstract: A bearing assembly for a worm drive supporting the worm of the worm drive with washer-shaped thrust slide bearings and bush-shaped radial slide (sintered oil-containing bearings) bearings. The thrust slide bearings are made of a resin containing 95 to 99.9 wt % of polyetheretherketone resin, which is an aromatic polyetherketone resin. Wear of the thrust slide bearings is reduced and its durability is improved, thereby preventing vibration and noise of the worm drive as well as improving its durability.Type: GrantFiled: October 8, 2009Date of Patent: October 21, 2014Assignee: NTN CorporationInventors: Masato Shimoda, Masahiko Mizutani
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Patent number: 8824894Abstract: When an ONU accommodating range is enlarged, and ONUs shorter and ONUs longer in a communication path to an OLT are accommodated in a PON at the same time, there is a need to change a light intensity at the time of transmitting a downstream signal in order that both of the ONUs receive a downstream signal from the OLT. When a near-end ONU receives a signal having a light intensity necessary to communicate between the OLT and a far-end ONU, there arises such a problem that the light intensity is as high as an ONU receiver fails. In order to eliminate the ONU failure of the above problem, prior to transmission of the downstream signal, a downstream signal transmission schedule (downstream light intensity map) is notified to all of the ONUs. An optical transceiver of the OLT has a function of adjusting an output light intensity, and adjusts the light intensity to values receivable by the individual ONUs when the signal arrives at the respective ONUs according to route distances to the respective ONUs.Type: GrantFiled: August 30, 2011Date of Patent: September 2, 2014Assignee: Hitachi, Ltd.Inventors: Masao Niibe, Masahiko Mizutani
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Publication number: 20140215566Abstract: A transmission network system includes a network terminating device connected to a user terminal and an authentication information device connected to the network terminating device through a transmission network. The transmission network is connected to a reference clock that holds a reference time. The network terminating device includes a terminating internal clock that synchronizes with the reference clock, when receiving a first frame from the user terminal, generates a second frame including a time outputted from the terminating internal clock as a request time on the basis of the first frame, and transmits the second frame to the authentication information device. The authentication information device generates time authentication information based on the request time included in the received second frame, generates a third frame including the generated time authentication information, and transmits the third frame to the transmission network.Type: ApplicationFiled: January 23, 2014Publication date: July 31, 2014Inventors: Shinya FUJIOKA, Yoshihiro ASHI, Masahiko MIZUTANI
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Patent number: 8667058Abstract: When data is disclosed to a plurality of users by using a transfer network and a transfer apparatus, data disclosure time control which cannot be adversely affected by the users is performed to reduce the difference in data disclosure time among the users. A transfer network system includes a distribution server serving as a data-distribution-source transfer apparatus, and a network terminal connected to distribution-destination user equipment. The distribution server and the network terminal each have a time keeping function and a time synchronization function for matching the time of the time keeping function with a master clock. The distribution server sends in advance disclosure data and disclosure time to the network terminal. When the time of the time keeping function of the network terminal matches the disclosure time, the network terminal sends the disclosure data to the user equipment.Type: GrantFiled: June 19, 2012Date of Patent: March 4, 2014Assignee: Hitachi, Ltd.Inventors: Shinya Fujioka, Yoshihiro Ashi, Masahiko Mizutani
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Publication number: 20140050078Abstract: In a redundant packet communication path including an active path and a backup path, user data that flows into the active path during a time when switching from the active path to the backup path is completed is transferred to a device at a protection zone receiving end to reduce a communication interruption time (traffic suspension time) in a user's point of view.Type: ApplicationFiled: March 7, 2013Publication date: February 20, 2014Applicant: HITACHI, LTD.Inventors: Aya SATO, Masahiko MIZUTANI, Masao NIIBE, Katsuyoshi SUZUKI
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Patent number: 8654766Abstract: An interconnection between fully synchronous networks and next-generation frame communications networks is disclosed. A means of bidirectional frame format conversion between a synchronous multiplexing system and a logical multiplexing system is provided, along with a method of transmitting data between different networks on a path as if it were being transmitted in the same network. Further, when converting network control information in an STM network into data suitable for a packet network, even across the boundary of a synchronous multiplexing system and a logical multiplexing system, a unified communication management means is provided over the whole path.Type: GrantFiled: May 7, 2012Date of Patent: February 18, 2014Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Yoshihiro Ashi, Masayuki Takase, Atsushi Iwamura, Akihiko Tanaka, Hideki Endo, Tohru Kazawa
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Patent number: 8554075Abstract: Switching process at the occurrence of a path trouble is performed more quickly to reduce the number of packet discards during a traffic transition from a currently used system path to a standby system path within a section to be protected. An OLT (210-W) refers to the DBA information of a PON section and, if receiving no CCM frame at a timing at which the same should be received, then determines that some trouble has occurred on the path (S801) and transmits, to an OAM-compliant NE (200-Z), an application-for-switching frame (1501) to notify the OAM-compliant NE (200-Z) of the abnormal condition. The OAM-compliant NE (200-Z) monitors the occurrence of the trouble within the PON section nearly in real time, starts a switching process (S802) and generates and transmits a standby-system delivery request (321) (S302, S803). An OAM-compliant NE (200-A) switches the communication path to the standby-system passing through an OLT (210-P).Type: GrantFiled: January 13, 2009Date of Patent: October 8, 2013Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Yusuke Yajima, Nobuyuki Yamamoto, Yoshihiro Ashi
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Publication number: 20130258842Abstract: A redundant path configuration method and a control method are disclosed. An intercommunication path for mutually transmitting and receiving a signal is provided among the BHEs each of which is a top of a tree. When failures occur in an active system path in certain AE, a standby system path (BHE) relays communication between the AE and the (active system) BHE so as to secure continuity of communication. The intercommunication path through which a data signal does not flow in a normal operation is used as a traffic accommodation path in an emergency among the BHEs. By setting a bypass between the tops of the trees, when a failure occurs in one tree, a signal is transferred from the active system BHE to the standby system path in which another BHE is a top to build a sub-tree bypassing the failure point and to secure a communication path.Type: ApplicationFiled: October 28, 2011Publication date: October 3, 2013Applicant: HITACHI, LTD..Inventor: Masahiko Mizutani
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Publication number: 20130182559Abstract: A transmission network is comprised of a network management system for collectively managing and controlling a plurality of transmission devices coupled mutually through transmission routes and the transmission network as well. The network management system includes a plane management table adapted to manage transmission planes defined as a set of paths in the transmission network, and the plane management table has the function to set and manage a transmission plane (working plane) applied during normal operation and besides, a single or a plurality of transmission planes (protection planes) applicable in the event of occurrence of a fault in the transmission network. Then, when a fault occurs in the transmission network, the network management system changes the applied plane to a suitable transmission plane.Type: ApplicationFiled: July 19, 2012Publication date: July 18, 2013Inventors: Shinya Fujioka, Yoshihiro Ashi, Masahiko Mizutani, Hideki Endo
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Patent number: 8488965Abstract: It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems.Type: GrantFiled: December 18, 2008Date of Patent: July 16, 2013Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Toshiki Sugawara, Hiroki Ikeda
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Patent number: 8457495Abstract: It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems.Type: GrantFiled: December 18, 2008Date of Patent: June 4, 2013Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Toshiki Sugawara, Hiroki Ikeda
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Patent number: 8457493Abstract: In the communication system, a master station is coupled to slave stations by a fiber network comprising a splitter and a reach extender, the master station includes a first bandwidth control section which determines, based on a request from each slave station, a first data amount of a signal transmitted in a first cycle, the reach extender includes: a distance measurement section which measures a distance or a time between the reach extender and each slave station; and a second bandwidth control section which determines a second data amount and transmission timing of a signal based on a request from each slave station and the first data amount, and each slave station transmits a signal with a data amount, which the first bandwidth control section determined based on a data amount and transmission timing determined in second cycles, to the master station in the first cycle.Type: GrantFiled: October 13, 2010Date of Patent: June 4, 2013Assignee: Hitachi, Ltd.Inventor: Masahiko Mizutani
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Patent number: 8428457Abstract: In the configuration of an optical communication system interconnecting a parent station and a plurality of child stations via an optical fiber network equipped with an optical splitter, RE is provided having a measuring unit for measuring a transmission distance or time to a child station, a determining unit for determining a timing when a child station transmits a signal, in accordance with a transmission bandwidth request from the child station, and a signal processing unit for processing a signal received from a child station and transmitting the processed signal to the parent station. When a burst signal is received from each child station at the determined timing, a portion of the header of the burst signal is deleted, and a dummy signal is inserted into the deleted area and a gap area between received burst signals to convert the burst signals into a series of signals to be sent to the parent station.Type: GrantFiled: April 26, 2010Date of Patent: April 23, 2013Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Yusuke Yajima, Akihiko Tsuchiya
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Patent number: 8422375Abstract: Communication arrangements wherein each of ONUs of a first or second PON transmits data toward a connected first or second OLT after a wait time period designated by the connected first or second OLT; the first communication device of the first packet communication network sends a first frame for measuring communication time period, to the second communication device of the second packet communication network through the first PON, and sends a second frame for measuring communication time period, to the second communication device through the second PON; and the second communication device calculates a difference of communication time period between the received first and second frames, and instructs the first or second OLT of the first or second PON, for correcting a wait time period which is set to the one or plural ONUs connected to the first or second OLT, based on the difference between communication time periods.Type: GrantFiled: September 22, 2011Date of Patent: April 16, 2013Assignee: Hitachi, Ltd.Inventors: Masahiko Mizutani, Yusuke Yajima, Takayuki Kanno, Takeshi Yasuda