Fujitsu Corporation

Naoto Miyauchi

Shigemasa Matsubara

Hiroaki Tamai

Yasuaki Kamimura

Mitsuaki Yasuoka

Takafumi Kawakami

Kazuya Takeuchi

Satoshi Ikeda

Katsumi Kobayashi

Taiji Kondo

Akira Okubo

Satoshi Kurosawa

Hiroaki Kawasumi

Yoshihiko Shirokura

Takahiro Koharagi

Takao Ito

Yukio Hayashi

Kobun Nakajima

Yosuke Nishikata

Masahiro Machida

Tetsuhiro Murata

A node includes a time difference measurement unit and a time setting unit. The time difference measurement unit measures a time difference between a first time based on latest received time information and a second time based on second-latest received time information. The time setting unit calculates an adjustment time difference when the time difference exceeds an allowable range of error that is smaller than an allowable range of maintainable communication, sets a time obtained by adding the adjustment time difference and the second time to the time of the node when the adjustment time difference is within the allowable range of maintainable communication, and sets a time obtained by adding a time difference corresponding to the allowable range of maintainable communication and the second time to the time of the node when the adjustment time difference exceeds the allowable range of maintainable communication.

Node and method for communication control

A communication device is provided in a wireless multi-hop network. The communication device receives a sequence number, a divided time acquired by dividing a time width allocated for transmitting detected usage data by a division number, and the division number. The communication device calculates a remainder by dividing the received sequence number by the division number and calculates a transmission offset time based on the remainder and the divided time. The communication device transmits the usage data based on the calculated transmission offset time.

Communication device and communication method

The present invention increases accommodation efficiency in a wireless master station for wireless slave stations, and efficiently uses wireless resources while controlling traffic. In a communication system in which a plurality of wireless slave stations---, . . . , perform wireless communication with wireless master stations-and-directly or through another wireless slave station and which performs communication from the wireless master stations with a collection control deviceby means of wired communication or the like. The collection control devicestores first through fourth threshold values a, b, c, and d in memory, and makes efficient use while suppressing traffic by performing a 'connection suppression notification', a 'specific high-frequency communication stop notification', and an &#x201c;accommodation refusal notification&#x201d;, and performs functionality control through stages according to the number of accommodated wireless slave stations.

Communication system, congestion avoidance method thereof, and meter reading system using communication system

Growing community of inventors

Tokyo, Japan

Naoto Miyauchi