Advanced Telecommunications Research Institute International

Nec Communication Systems, Ltd.

Nec Corporation

Nec Communications Systems, Ltd.

Peter Davis

Tetsuya Ito

Akira Matsumoto

Satoko Itaya

Sadao Obana

Naoto Kadowaki

Jun Hasegawa

Akio Hasegawa

Stefan Aust

Naoki Yoshinaga

Rie Tanaka

Yoshihisa Kondo

Shinichi Doi

Peng Shao

Taku Konishi

Kenichi Abe

Akira Yamaguchi

Hiroyuki Iizuka

Yuichiro Ezure

Hisato Iwai

Ryutaro Suzuki

Yasuhisa Takizawa

Makoto Kawai

An assessment device () includes: a request acquirer () that accepts an evaluation target from a user terminal (); a model acquirer () and a data acquirer () that select a main model for evaluating the evaluation target accepted by the request acquirer () from a plurality of models and select supplemental data to be supplemented for using the main model (data to be input into the main model, a sub-model, or data to be input into the sub-model) when the data to be input into the main model is insufficient; an executor () that evaluates the evaluation target based on the main model and supplemental data selected by the model acquirer () and the data acquirer (); and a transmitter () that provides a result of the evaluation by the executor () to the outside.

Assessment device, assessment system, assessment method, and computer-readable storage medium

A communication information registering unit () acquires communication information that contains a sender, a receiver, and a sending time of information communicated between users that are communicating, and stores the communication information in a storage unit (). A response time calculation unit () finds response time of the users from the communication information. A threshold value setting unit () finds a threshold value for determining the statuses of the users from distribution of frequencies of the response time. A current status determination unit () determines the status of a counterpart user from the response time by using the threshold value. A notification unit () notifies a user of the current status of its counterpart user.

Communication support system, communication support method, and recording medium

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.

Wireless communication terminal

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.

Wireless communication device that is capable of improving data transmission efficiency, associated network, and method

Wireless communication device that is capable of improving data transmission efficiency

When wireless communications are made between a first wireless device and a second wireless device along a route, two wireless devices which exist between the first and second wireless devices each determine the lowest maximum transmission rate (11 Mbps) in the wireless intervals on the route from themselves to the second wireless device to be their own transmission rate txRate (11 Mbps) and two other wireless devices which exist between the first and second wireless devices each determine the lowest maximum transmission rate (54 Mbps) in the wireless intervals on the route from themselves to the second wireless device to be their own transmission rate txRate (54 Mbps).

Wireless device which can improve stability in wireless communications and wireless network using the same

Radio apparatuses each has a plurality of channels and, when data is to be transmitted, selects a specific channel having relatively low signal interference from the plurality of channels. Each radio apparatus spreads transmission data with a prescribed spread code arbitrarily selected from a plurality of spread codes, and modulates the spread spectrum signal with the frequency of the specific channel to transmit. As a result, delay in an autonomously established wireless network can be reduced.

Radio apparatus

In wireless communication using links with neighbor wireless devices, a wireless device calculates ratios of throughput to maximum throughput for the links and calculates the costs of the links using the calculated ratios. Then the wireless device finds, for each destination, a route in which the sum of such calculated link costs is the minimum, and sends a packet to the destination using the route. As a consequence, routing can be done according to an isotonic, easy-to-implement routing protocol.

Wireless device which selects routes excluding loop routes and a mesh network including the same

Radio devices (to) receive a prescribed number of Hello packets from each of n radio devices existing within one hop from each radio device, detects six pairs of maximum and minimum values MAX[] and MIN[] to MAX[] and MIN[] based on the plurality of reception signal strengths of the plurality of received Hello packets, detects two adjacent maximum values having the largest difference among six pairs of maximum and minimum values D_MAX[] and D_MIN[] to D_MAX[] and D_MIN[] when the six maximum values MAX[] to MAX[] are in descending order, and determines the average of two minimum values corresponding to the detected two maximum values as a threshold. The radio devices (to) each produce a routing table including routes having reception signal strengths equal to or more than the threshold.

Radio device

A radio apparatus forming a radio network system calculates a calculated distance, based on a tentative self-position and tentative positions of a plurality of radio apparatuses existing in the vicinity. The radio apparatus successively and autonomously corrects the tentative self-position so that the calculated distance comes closer to the measured distance, relying more heavily on the calculated distance than the measured distance between itself and each of the plurality of radio apparatuses, and determines the position of itself. Other radio apparatuses also successively correct the tentative self-positions by the same method as the radio apparatus, and determine the positions of themselves.

Radio network system capable of autonomous estimation using position correction

A radio device is located far from other radio devices in a radio network system. The radio device determines a threshold WIth for detecting a strength equal to or more than the minimum strength of radio waves transmitted/received in a stable radio wave environment based on a plurality of reception signal strengths of Hello packets received from radio devices adjacent to the radio device. Then, if the number of radio devices adjacent to the radio device when the threshold WIth is introduced is less than a standard value (such as five), the radio device stores the adjacent radio devices in the neighbor list without introducing the threshold WIth, and then, maintains in the routing table the routing information of routes passing through the adjacent radio devices based on the neighbor list.

Radio device for preventing isolated radio devices in network

The route maintenance unit outputs a period setting request to the period setting unit when the communication unit normally receives a Hello packet for the first time. The period setting unit sets a link connection confirmation period in response to the period setting request and outputs the set period to the route maintenance unit. The route maintenance unit maintains a radio link between the radio device in which the route maintenance unit is provided and an adjacent device upon receiving a data packet other than a Hello packet from the adjacent radio device even if a Hello packet is not received in the link connection confirmation period. Consequently, route disconnection or switching occurs less often.

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Kyoto, Japan

Peter Davis