Patents Assigned to NEC Communication Systems, Ltd.
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Publication number: 20170231030Abstract: A communication device includes a wireless communication unit, an in-transmission information generating unit, and a neighboring signal presence information generating unit. The wireless communication unit transmits and receives wireless frames via an antenna. The in-transmission information generating unit generates in-transmission information representing whether or not a wireless frame is being transmitted from the antenna. The neighboring signal presence information generating unit generates neighboring signal presence information representing whether or not a signal of a predetermined level or higher is present on a wireless channel that is the same as a wireless channel of the wireless frame.Type: ApplicationFiled: August 3, 2015Publication date: August 10, 2017Applicant: NEC Communication Systems Ltd.Inventors: Akira MATSUMOTO, Peng SHAO, Yuki BABA
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Publication number: 20170093470Abstract: The solution of the present invention is a precoding that allows an optimal use of multiple-antennas in a MIMO system. The precoding uses codebooks that are optimized for long-range wireless transmissions. A modified Kerdock codebook {wkmi} allows further improvement of the precoding gain. The modified Kerdock codebook {wkmi} contains new codewords wkmi that have been modified in order to further improve the transmit bit error rate (BER). The modified codebook {wkmi} allows a precoding gain that is between 2-3 dB. The present invention improves the transmit bit error rate (BER) of a wireless system. It allows a longer range in outdoor MIMO systems. Less signal outage is the result which allows that wireless signals can be transmitted over several kilometers.Type: ApplicationFiled: May 23, 2014Publication date: March 30, 2017Applicant: NEC Communication Systems, LtdInventor: Stefan AUST
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Patent number: 9554330Abstract: A wireless communication device 81 operates in either a ROD mode or a non-ROD mode. The non-ROD mode sets the state of the device to an active state that the device can perform wireless communication compliant with a first communication scheme with a communication destination device 82. The ROD mode: sets the state of the device to either the active state or a sleep state that the device can receive an activation instruction signal compliant with a second communication scheme requiring smaller electric power to receive a signal than the first communication scheme and cannot perform wireless communication compliant with the first communication scheme with the communication destination device; sets the state of the device to the sleep state when a predetermined sleep condition is satisfied; and sets the state of the device to the active state when the device receives the activation instruction signal.Type: GrantFiled: November 16, 2012Date of Patent: January 24, 2017Assignee: NEC Communication Systems, Ltd.Inventors: Stefan Aust, Toshiyasu Tanaka, Tetsuya Ito
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Publication number: 20170013556Abstract: In order to solve a problem that, when a plurality of wireless communication modes are simultaneously used, interference between the plurality of wireless communication modes cannot be effectively prevented, a wireless communication control device according to the present invention includes a first communication mode control unit performing wireless communication in a first wireless communication mode, and a second communication mode control unit performing wireless communication in a second wireless communication mode. The second communication mode control unit detects a start of wireless communication in the first wireless communication mode, operates not to perform wireless communication in the second wireless communication mode during a wireless communication period in the first wireless communication mode, and operates to perform wireless communication in the second wireless communication mode outside a wireless communication period in the first wireless communication mode.Type: ApplicationFiled: February 23, 2015Publication date: January 12, 2017Applicant: NEC Communication Systems, LtdInventors: Toshiyasu TANAKA, Stefan AUST
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Publication number: 20170006540Abstract: A wireless base station (1) includes a wakeup device (13) and a main device (14). When the main device (14) is in a sleep mode, the wakeup device (13) is connected to the antenna (11). Then, when the wakeup device (13) receives a wakeup signal for activating the wireless base station (1) from a terminal device assigned to the wireless base station (1) in a communication band used for wireless communication with the terminal device and when the information for identifying a wireless base station to be activated contained in the received wakeup signal is identical with the identification information of the wireless base station (1), the wakeup device (13) outputs a driving signal to the main device (14). The main device (14) transitions from the sleep mode to an operating mode in response to the driving signal from the wakeup device (13).Type: ApplicationFiled: September 16, 2016Publication date: January 5, 2017Applicants: ADVANCED TELECOMMUNICATIONS RESEARCH INSTITUTE INTERNATIONAL, NEC COMMUNICATION SYSTEMS, LTD.Inventors: Hiroyuki Yomo, Yoshihisa Kondo, Suhua Tang, Sadao Obana, Tetsuya Ito, Akira Matsumoto, Koichi Yoshimura
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Patent number: 9532379Abstract: A receiver has an ID that includes three signal detection intervals (S1, S2, S3). The three signal detection intervals (S1, S2, S3) are detected as the receiver detects a signal consisting of a value larger than a threshold at each of the detection timings (DT1 to DT4). The transmitter transmits four radio frames (FR1 to FR4) such that each of the radio frames straddles the corresponding one of the detection timings (DT1 to DT4) in the receiver.Type: GrantFiled: March 4, 2013Date of Patent: December 27, 2016Assignees: ADVANCED TELECOMMUNICATIONS RESEARCH INSTITUTE INT, NEC COMMUNICATION SYSTEMS, LTD.Inventors: Yoshihisa Kondo, Hiroyuki Yomo, Suhua Tang, Takatoshi Kimura, Masahito Iwai, Tetsuya Ito
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Publication number: 20160366702Abstract: A wireless communication terminal has: a wireless module part which transmits a radio frame signal; a transmission loss information detection part which detects transmission loss information representing whether or not the radio frame signal transmitted by the wireless module part has reached a transmission destination; a collision information detection part which detects collision information representing an aspect of collision between the radio frame signal transmitted by the wireless module part and another radio frame signal; and a transmission control part which controls a transmission process executed by the wireless module part, on a basis of the transmission loss information and the collision information.Type: ApplicationFiled: August 14, 2014Publication date: December 15, 2016Applicant: NEC Communication Systems, LtdInventors: Yuki BABA, Akira MATSUMOTO, Peng SHAO
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Patent number: 9521613Abstract: A wireless base station (1) includes a wakeup device (13) and a main device (14). When the main device (14) is in a sleep mode, the wakeup device (13) is connected to the antenna (11). Then, when the wakeup device (13) receives a wakeup signal for activating the wireless base station (1) from a terminal device assigned to the wireless base station (1) in a communication band used for wireless communication with the terminal device and when the information for identifying a wireless base station to be activated contained in the received wakeup signal is identical with the identification information of the wireless base station (1), the wakeup device (13) outputs a driving signal to the main device (14). The main device (14) transitions from the sleep mode to an operating mode in response to the driving signal from the wakeup device (13).Type: GrantFiled: February 16, 2012Date of Patent: December 13, 2016Assignees: Advanced Telecommunications Research Institute International, NEC Communication Systems, LTD.Inventors: Hiroyuki Yomo, Yoshihisa Kondo, Suhua Tang, Sadao Obana, Tetsuya Ito, Akira Matsumoto, Koichi Yoshimura
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Publication number: 20160295512Abstract: A base station includes a wakeup signal transmission part transmitting transmission signal information to a wireless terminal by wireless communication. The transmission signal information includes a wakeup signal starting a given function included by the wireless terminal. The wakeup signal transmission part transmits the transmission signal information including connection information in addition to the wakeup signal to the wireless terminal. The connection information is information for causing the wireless terminal of a destination of transmission of the wakeup signal to connect by wireless communication using the given function.Type: ApplicationFiled: September 5, 2014Publication date: October 6, 2016Applicants: NEC Communication Systems, Ltd, NEC CorporationInventors: Yukihiro HARA, Yohei MIYAMA, Tomonori KUMAGAI, Shinji MASUDA, Kenki TAKAGI
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Patent number: 9461772Abstract: A packet interval (a time difference between sequentially received packets) in a certain previous time is calculated and a cumulative distribution function of the calculated packet interval is obtained. Meanwhile, a function value-corresponding to-flow end that is a boundary value of the cumulative distribution function to be considered as a flow end (timeout) in the range of a cumulative distribution function value is stored. From the cumulative distribution function obtained as described above, a value of a packet interval mapped to a cumulative distribution function value that matches the function value-corresponding to-flow end is set as a threshold. That is, the threshold is dynamically set based on a previous packet interval. Therefore, a packet stop period from a last packet reception time to a current time is measured, and it is detected as a flow timeout at a timing when the measured value is equal to or greater than the threshold.Type: GrantFiled: July 24, 2012Date of Patent: October 4, 2016Assignee: NEC Communication Systems, Ltd.Inventors: Hiroyuki Iizuka, Toshiyasu Tanaka, Koichi Yoshimura, Masahito Iwai, Tetsuya Ito
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Publication number: 20160262049Abstract: A transmission part transmits a packet by radio. A power detection part performs, at a given cycle, sampling of power of a spatial radio signal in a packet transmission period during which the transmission part transmits the packet. A collision detection part calculates, as an index value, at least one of the average value and the degree of variation of power of the spatial radio signal in the packet transmission period on the basis of sampled data obtained in the sampling by the power detection part. The collision detection part also determines a reference value on the basis of transmission power of the packet. Then, the collision detection part detects whether or not collision of the packet is present by comparing the index value with the reference value.Type: ApplicationFiled: September 5, 2014Publication date: September 8, 2016Applicant: NEC Communication Systems, LtdInventors: Peng SHAO, Akira MATSUMOTO, Ikumi WADA, Yuki BABA
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Patent number: 9408148Abstract: A terminal device (1) frame-length-modulates an identifier of the radio apparatus (3) to generate a plurality of frames having a plurality of frame lengths, and transmits the generated plurality of frames to an access point (2) over wire or wireless communication. The access point (2) transfers the plurality of frames transmitted by the terminal device (1) to the radio apparatus (3) in the IP or MAC layer. The radio apparatus (3) detects the plurality of frame lengths of the plurality of frames received from the access point (2) and decodes the detected plurality of frame lengths to obtain an identifier. If the obtained identifier matches the identifier of the radio apparatus (3), the radio apparatus (3) transitions to active mode.Type: GrantFiled: March 18, 2013Date of Patent: August 2, 2016Assignees: ADVANCED TELECOMMUNICATIONS RESEARCH INSTITUTE INT, NEC COMMUNICATION SYSTEMS, LTD.Inventors: Takatoshi Kimura, Yoshihisa Kondo, Hiroyuki Yomo, Tetsuya Ito, Yukihiro Hara
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Patent number: 9374784Abstract: A terminal device 2 transmits a wireless frame having a frame length or amplitude that represents the ID of a wireless base station 1 to be woken up to the wireless base station 1. The wireless base station 1 detects the wakeup ID from the frame length or amplitude of the wireless frame from the terminal device 2, and, if the detected wakeup ID is identical with its own ID, transitions from a sleep mode to an operating mode. In this case, the wireless frame is the same wireless frame as that transmitted and received by the wireless communication module of the terminal device 2 to and from the wireless base station 1.Type: GrantFiled: February 16, 2012Date of Patent: June 21, 2016Assignees: ADVANCED TELECOMMUNICATIONS RESEARCH INSTITUTE INTERNATIONAL, NEC COMMUNICATION SYSTEMS, LTD.Inventors: Yoshihisa Kondo, Hiroyuki Yomo, Suhua Tang, Sadao Obana, Tetsuya Ito, Koichi Yoshimura, Masahito Iwai, Toshiyasu Tanaka, Hiroyuki Iizuka
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Patent number: 9075676Abstract: An information processing terminal is provided with a data acquiring means for reading data from an external recording medium; a program storing means for storing a plurality of application programs; a program executing means for executing the stored application programs; and a program selecting means for selecting the application program to be executed by the program executing means. The program selecting means selects the application program to be executed from the programs stored in the program storing means, corresponding to the data acquired through the data acquiring means, and processes the data acquired through the data acquiring means by the application program selected by the program selecting means.Type: GrantFiled: May 11, 2007Date of Patent: July 7, 2015Assignees: NEC CORPORATION, NEC Communication Systems Ltd.Inventors: Tomoharu Yamaguchi, Mie Noda, Yuichi Nino
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Patent number: 9037117Abstract: A wireless communication terminal includes a communication status measurement element for measuring communication status data representing a communication status of the self terminal at the time of wireless communications; a reference data storage element for storing respective pieces of preset reference data representing communication statuses of a terminal which can be measured at respective locations at the time of wireless communications, in association with respective pieces of location data identifying the respective locations, and a location specifying element for comparing the communication status data measured by the communication status measurement element with the respective pieces of reference data stored in the reference data storage element, and based on the comparison result, specifying a location corresponding to the location data associated with a particular piece of reference data as a location of the self terminal.Type: GrantFiled: August 28, 2010Date of Patent: May 19, 2015Assignee: NEC COMMUNICATION SYSTEMS, LTD.Inventors: Stefan Aust, Tetsuya Ito, Akira Matsumoto, Peter Christopher Davis
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Patent number: 9030945Abstract: A wireless communication device includes a data transmission and reception section that wirelessly transmits a plurality of test packets; a signal sensing section that senses a power of a spatial radio wave signal on a frequency channel that is the same as the plurality of test packets and outputs sample data of the sensed spatial radio wave signal; a calculation processing section that converts the sample data into time series sample data; a collision detection section that calculates a packet collision rate based on the number of packet collisions and the number of the plurality of test packets if there is a packet collision due to interference of the plurality of test packets with another communication; and a control section that adjusts a parameter that the data transmission and reception section uses based on a calculation result of the collision detection section.Type: GrantFiled: October 3, 2014Date of Patent: May 12, 2015Assignee: NEC Communication Systems, Ltd.Inventors: Peng Shao, Stefan Aust, Akira Matsumoto, Tetsuya Ito, Peter Davis
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Patent number: 9025697Abstract: A transmitter incorporates a table (TBL1) for assigning the frame lengths of 560 ?s and 600 ?s to the code “0” in a binary system and assigning the frame lengths of 600 ?s and 560 ?s to the code “1” in the binary system. The transmitter refers to the table (TBL1) and assigns the two frame lengths of 560 ?s and 600 ?s and the two frame lengths of 600 ?s and 560 ?s to the codes “0” and “1”, respectively, in the code sequences [0,0], [0,1], [1,0] and [1,1] representing the transmission information “0” to “3” represented using the binary system, and sequentially transmits four radio signals having the assigned four frame lengths.Type: GrantFiled: February 25, 2013Date of Patent: May 5, 2015Assignees: Advanced Telecommunications Research Institute International, NEC Communication Systems, Ltd.Inventors: Yoshihisa Kondo, Hiroyuki Yomo, Suhua Tang, Takatoshi Kimura, Masahito Iwai, Yukihiro Hara, Tetsuya Ito
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Patent number: 9009160Abstract: An information classification system 100 includes: a classified information storing part 101 for storing classified information having already been classified into a certain group and group specification information for specifying the group, in association with each other; and a confidence calculating part 102 for calculating confidence having a value depending on a probability that a group which is specified based on unclassified information as a target to be classified and classified information selected as reference information from among the stored classified information and into which the unclassified information should be classified is a true group.Type: GrantFiled: June 15, 2011Date of Patent: April 14, 2015Assignee: NEC Communication Systems, Ltd.Inventors: Stefan Aust, Akira Matsumoto, Tetsuya Ito, Koichi Yoshimura, Soshi Kuroshima
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Patent number: 8879402Abstract: A wireless communication device includes a data transmission and reception section that wirelessly transmits a plurality of test packets; a signal sensing section that senses a power of a spatial radio wave signal on a frequency channel that is the same as the plurality of test packets and outputs sample data of the sensed spatial radio wave signal; a calculation processing section that converts the sample data into time series sample data; a collision detection section that calculates a packet collision rate based on the number of packet collisions and the number of the plurality of test packets if there is a packet collision due to interference of the plurality of test packets with another communication; and a control section that adjusts a parameter that the data transmission and reception section uses based on a calculation result of the collision detection section.Type: GrantFiled: June 12, 2012Date of Patent: November 4, 2014Assignee: NEC Communication Systems, Ltd.Inventors: Peng Shao, Stefan Aust, Akira Matsumoto, Tetsuya Ito, Peter Davis
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Publication number: 20140226758Abstract: A packet interval (a time difference between sequentially received packets) in a certain previous time is calculated and a cumulative distribution function of the calculated packet interval is obtained. Meanwhile, a function value-corresponding to-flow end that is a boundary value of the cumulative distribution function to be considered as a flow end (timeout) in the range of a cumulative distribution function value is stored. From the cumulative distribution function obtained as described above, a value of a packet interval mapped to a cumulative distribution function value that matches the function value-corresponding to-flow end is set as a threshold. That is, the threshold is dynamically set based on a previous packet interval. Therefore, a packet stop period from a last packet reception time to a current time is measured, and it is detected as a flow timeout at a timing when the measured value is equal to or greater than the threshold.Type: ApplicationFiled: July 24, 2012Publication date: August 14, 2014Applicant: NEC COMMUNICATION SYSTEMS, LTDInventors: Hiroyuki Iizuka, Toshiyasu Tanaka, Koichi Yoshimura, Masahito Iwai, Tetsuya Ito