Nippon Telegraph and Telephone Corporation

Yokogawa Electric Corporation

Shinya Otsuki

Kazuyoshi Saito

Satoru Aikawa

Tomoaki Kumagai

Kengo Nagata

Tomoaki Ogawa

Hiroyuki Nakamura

Atsushi Ohta

Junichi Iwatani

Makoto Umeuchi

Masayoshi Nabeshima

Hiroshi Sakamoto

Akinori Hirukawa

Tomoki Murakami

Takeo Tanaami

Yasuhiko Inoue

Yasushi Takatori

Takafumi Hayashi

Masashi Iwabuchi

Nobuhiro Tomosada

Yasuhito Kosugi

Kengo Nataga

A wireless transmission device transmits a radio signal with a plurality of beam patterns and outputs transmission beam identifiers corresponding to the beam patterns to an object detection device, a wireless reception device receives the radio signal transmitted by the wireless transmission device with a plurality of beam patterns, measures received signal strength for each of the beam patterns and outputs reception beam identifiers and the received signal strength to the object detection device, and the object detection device detects an object within a detection area on the basis of the transmission beam identifiers, the reception beam identifiers and the received signal strength. This enables device-free object detection by utilizing a beamforming function, so that it is possible to achieve high detection accuracy while preventing increase in cost.

Object detection method, object detection device, and object detection system

A predetermined radio base station and subordinate radio terminals detect signals (beacons) regularly transmitted by other radio base stations, transmit information about radio channels and base station identifiers of the detected signals, and position information about the radio terminals to an interference area detection device to aggregate the information and the position information as a base station-base station detection list and a terminal-base station detection list. The interference area detection device compares the lists, determines, for each of positions of the subordinate radio terminals to the predetermined radio base station, whether both of the signal of the predetermined radio base station and a signal of another radio base station, which cannot be detected by the predetermined radio base station, are detected or not, and determines that a position where both of the signals are detected is within an interference area if the predetermined radio base station and the other radio base station detected at the position use the same radio channel.

Interference area detection method for wireless communication system, interference area detection system, interference area detection device, and interference area detection program

A plurality of access points configured to communicate with a subordinate wireless LAN terminal, an information collecting device configured to collect a frame respectively transmitted and received between the plurality of access points and the wireless LAN terminal, and extract information on communication quality of an access point of the plurality of access points from a header of the frame, and an information collecting server configured to acquire the information on the communication quality of the access point from the information collecting device, analyze the information to determine whether the communication quality is good or bad for each of the plurality of access points, and execute processing of externally displaying or notifying a result that is determined are included.

Wireless LAN communication system, access point communication quality determination method, and information collection server

There are provided a plurality of radio devices detecting an interference source signal transmitted by an interference source and generating pieces of air time information showing whether the interference source signal exists or not for each predetermined time unit; and an aggregation device estimating air time of the interference source by acquiring the pieces of air time information from the plurality of radio devices and aggregating/integrating the acquired pieces of air time information for each predetermined unit time, matching timings.

Wireless communication system, aggregation device, interference source air time acquisition method, and interference source air time acquisition program

A wireless base station and a first wireless terminal include means for collecting first wireless performance information regarding wireless communication in both a downstream direction and an upstream direction and transmitting the first wireless performance information to a wireless performance measurement device. The wireless base station and a second wireless terminal include means for collecting second wireless performance information regarding wireless communication in both the downstream direction and the upstream direction and transmitting the second wireless performance information to the wireless performance measurement device. The wireless performance measurement device includes means for obtaining a first comparison result by comparing the first wireless performance information regarding the upstream direction and the downstream direction, obtaining a second comparison result by comparing the second wireless performance information regarding the upstream direction and the downstream direction, and determining the location where an abnormality occurred in accordance with a result of a comparison of the first comparison result and the second comparison result. The location is determined from among the wireless base station, the first wireless terminal, the second wireless terminal, and a wireless propagation environment between the wireless base station and the first wireless terminal and between the wireless base station and the second wireless terminal.

Radio performance measurement system, radio performance measurement method, radio performance measurement device, and radio performance measurement program

Provided is an antenna placement method in a system for detecting an object in a detection area between at least one set of a transmission station and a reception station by a wireless signal. The antenna arrangement method includes: making the transmission station having a plurality of antennas transmit a measurement signal for measuring channel state information; making the reception station having a plurality of antennas measure the channel state information based on the measurement signal and notify a detection server of a result of the measurement; and making the detection server perform processing where the detection server detects an object based on the channel state information, calculates at least one of a channel capacity and an eigenvalue distribution based on a propagation channel matrix between the transmission station and the reception station, and determines an antenna arrangement where the channel capacity becomes a largest or an antenna arrangement where spreading of the eigenvalue distribution becomes a smallest.

Antenna placement method and antenna selection method

There are provided an information collecting device configured to collect a frame A transmitted and received between a wireless LAN base station that is an evaluation target and a wireless LAN terminal subordinate to the wireless LAN base station that is the evaluation target and a frame B transmitted and received between a wireless LAN base station that is a non-evaluation target and a wireless LAN terminal subordinate to the wireless LAN base station that is the non-evaluation target, and extract radio information on communication quality of each of the wireless LAN base stations from a header of a corresponding one of the frames A and B, and a wireless LAN communication quality estimation device configured to acquire, from the wireless LAN base station that is the evaluation target, information on the number of currently connected wireless LAN terminals, acquire, from the information collecting device, the radio information on the communication quality of each of the wireless LAN base stations, and analyze the information to estimate whether the communication quality of the wireless LAN base station that is the evaluation target is good or bad.

Wireless LAN communication quality estimation method, wireless LAN communication quality estimation system, information collection device, and wireless LAN communication quality estimation device

In a wireless information collecting method executed by at least one user terminal device that measures wireless information used in a site survey and a server device that stores the wireless information and performs the site survey, the user terminal device performs a step of periodically measuring a current position and transmitting positioning information indicating the current position to the server device, and a step of measuring the wireless information in accordance with a wireless information measurement number instructed by the server device and transmitting wireless information including a position and time to the server device. The server device performs a step of associating a position of the user terminal device and time with the wireless information and creating and updating a condition map indicating a wireless information measurement number at a position and time at which a site survey is performed, and a step of collating the current position of the user terminal and the time with the condition map and transmitting an instruction for the wireless information measurement number based on the current position of the user terminal device and the time to the user terminal device.

Radio information collection method and radio information collection system

When a transmission rate of each of lines that transmit data simultaneously between two STAs by using a plurality of radio channels and/or MIMO can be set independently, one data frame is fragmented in accordance with the transmission rates of the respective lines so as to generate a plurality of data packets having the same packet time length and data sizes equal to or smaller than a maximum data size. Those data packets are transmitted simultaneously by using a plurality of radio channels, or one radio channel and MIMO, or a plurality of radio channels and MIMO.

Wireless packet communication method

In retransmission processing due to a failure of transmission of data packets, a plurality of data packets are simultaneously transmitted between two STAs by utilizing multiple wireless channels and MIMO, and the number of idle channels and the number of retransmission packets are compared. Then, when both of the numbers are different or only when the number of idle channels is larger than the number of retransmission packets, the retransmission packets are reconstructed according to the number of idle channels, and the reconstructed retransmission packets are simultaneously transmitted by using the idle channels.

Wireless packet communication method and wireless packet communication apparatus

Data packets are transmitted between two STAs capable of using plural radio channels and MIMO together, by using idle channels and MIMO. When at least one idle channel has been detected, plural data packets are generated in the same number as the sum of MIMO numbers of the respective idle channels, in which the data packets are generated from one or plural data frames, and plural data packets having the same packet time length are transmitted simultaneously between the two STAs by using the idle channels and MIMO.

A plurality of types of available transmission rates to be used for transmission of data packets are individually managed for each receiver terminal. When there are a plurality of data packets to be transmitted onto a transmission buffer and when it is possible to transmit said plurality of data packets simultaneously, the packet sizes representative of the data amounts of the respective data packets are referred to as well as the transmission rates of the respective data packets associated with the receiver terminals. The packet time lengths (transmission times) defined by the packet sizes and transmission rates are checked for the respective data packets. A plurality of data packets whose packet time lengths are approximately equal to each other are selected regardless of their receiver terminals. The transmissions of the plurality of selected data packets are commenced simultaneously by use of a plurality of radio channels.

For data packet transmission in special format generated by connecting or patching data frames, a request packet and reply packet receivable only by STAs supporting the special format are transmitted/received before the data packet transmission, to check and manage the STA supporting the special format. Based on management information in own station, the data packet is transmitted in the special or standard format according to a receive-side STA. For generating plural data packets in special format in which plural data frames are patched, the plural data frames having subheaders added are connected and divided to data blocks. A main header including information necessary to restore patched data frames are added to each data block, and a control information field and a frame check field of a data packet are added before and after the data block having the main header added thereto, respectively, to generate data packets.

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Kanagawa, Japan

Shinya Otsuki