Nippon Telegraph and Telephone Corporation

Ntt Broadband Platform, Inc.

Makoto Umeuchi

Tomoaki Ogawa

Hiroshi Sakamoto

Hiroyuki Nakamura

Shinya Otsuki

Junichi Iwatani

Masayoshi Nabeshima

Tomohiro Tokuyasu

Toshihiro Manabe

Takefumi Hiraguri

Tomoki Murakami

Masaru Miyamoto

Kengo Nagata

Masahiro Umehira

Masamichi Hosoda

Tadashi Mori

Hiroshi Hojo

Tadao Kobayashi

Yasushi Hanakago

Masamitsu Nakura

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

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

An object is to enable high-accuracy position estimation of a wireless terminal station by efficiently performing connection between a wireless base station and the wireless terminal station using multiple distributed antennas. A position estimation apparatus configured to estimate a position of a wireless terminal station between a wireless base station that can perform transmission and reception by switching between a plurality of distributed antennas arranged in a distributed manner via cables with known lengths, and the wireless terminal station configured to communicate with the wireless base station, includes: a means 1 for measuring a no-delay RTT or measuring a statistical processing RTT when the wireless base station exchanges a measurement signal and a response signal with the wireless terminal station in each of the distributed antennas and measures an RTT, which is a round trip time between the wireless base station and the wireless terminal station, a delay time having been removed from the no-delay RTT using a reception time of the measurement signal and a transmission time of the response signal, and the statistical processing RTT being measured using statistical processing for making the delay time constant using a plurality of instances of exchanging a measurement signal and a response signal; and means 2 for estimating the position of the wireless terminal station based on the no-delay RTT or the statistical processing RTT of each of the distributed antennas.

Position estimation method and position estimation apparatus

An application to be booted is selected and operation of the application is controlled according to status of a link between an access point and a station. A station (STA) which can be connected to an access point (AP) includes a link information obtaining procedure which obtains link information including an identifier of the AP to which the STA is connected while the STA is connected to the AP and an application control procedure which selects an application to be booted according to the link information by referring to an action profile in which an identifier of the link information and an application to be booted are related and registered.

Station, station control method, and station control program

A probe request for an access point scan is transmitted over a specified radio channel according to an order of scanning, a connection candidate AP list including information indicating an access point which transmits a probe response and a received signal strength indication is generated when the probe response is received, the connection candidate AP list is referred to, one access point is selected from access points whose corresponding received signal strength indications exceed a predetermined threshold, connection processing is performed on the one access point being selected on the specified radio channel, and scanning is repeatedly performed by specifying a radio channel which is second in the order until scanning on all radio channels for which the order of scanning is set is completed when no probe response is received or the connection candidate AP list includes no received signal strength indication which exceeds the threshold.

Access point scan method, access point scan apparatus, and storage medium storing access point scan program

In an access point scan method by which a station disconnected from an access point scans for a next access point to which the station can be connected at a predetermined scan interval, the station sets a shorter scan interval when a possibility of connection to the next access point to which the station can be connected is presumed to be high or a need for connection is presumed to be great, and sets a longer scan interval when the possibility of connection is presumed to be low or the need for connection is presumed to be small, based on one of information on the access point to which the station being connected just before disconnection and information on the station.

Access point scan method, storage medium storing scan program, and station

A wireless relay device connecting a wireless terminal to one of a plurality of access networks with different wireless interfaces and performing relay processing between the wireless terminal and one of the plurality of access networks being connected, the wireless relay device including a wireless interface on local side to be connected to the wireless terminal, a plurality of wireless interfaces on network side to be connected to the plurality of respective access networks, and a connection control section which boots the plurality of wireless interfaces on network side when the wireless interface on local side receives a signal from the wireless terminal, connects a wireless interface on network side establishing a fastest connection and the wireless interface on local side, and connects the wireless terminal to an access network corresponding to the wireless interface on network side establishing the fastest connection.

Wireless relay device and wireless communication system

In an ATM transmission system in which a plurality of ATM cells are grouped to a packet with an end of ATM cell having an EOP (End Of Packet) flag, a transmitting station comprises a transmit buffer for storing temporarily ATM cells to be transmitted, a transmit cell process means which discards all the ATM cells in the group in case that a NAK response indicating loss or wrong reception of an ATM cell is received from a receiving station, and an EOP cell generator for transmitting an EOP cell which has said EOP flag in stead of the discarded ATM cells. As no ATM cell in a packet is transmitted after an erroneous ATM cell is detected, no useless ATM cell which would be discarded in a destination terminal equipment because of an erroneous ATM cell occupies a transmission line when an erroneous ATM cell is detected, and traffic is saved.

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Yokosuka, Japan

Makoto Umeuchi