Tetsuya Kawai

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The wireless sensor network (WSN) is one of the most promising technologies which helps making our society safe, secure, and comfortable. A WSN as a social infrastructure must transmit critical information faster and more reliable than other information. In this paper, we propose an autonomous and distributed mechanism, called an " assured corridor "(More)
A wireless sensor network for automatic meter reading needs to satisfy two contradicting requirements, i.e., long lifetime and prompt detection and notification of emergency. We propose a sensor network protocol for this purpose , in which sensor nodes operate on a low duty cycle while the latency of transmission is guaranteed to be less than a certain(More)
Wireless sensor networks are expected to become an important social infrastructure which helps our life to be safe, secure, and comfortable. In this paper, we propose design methodology of a network architecture for fast and reliable transmission of urgent information in wireless sensor networks. In the methodology, several simple and fully-distributed(More)
SUMMARY Wireless sensor networks are expected to play an essential role as a social infrastructure to realize our safe and secure living environment. In such a network, critical information must be transmitted faster and more reliably than other information. We propose a distributed transmission mechanism which enables emergency packets to be carried with(More)
Wireless sensor networks used as a social infrastructure must be capable of differentiating and prioritizing transmission of urgent sensor information over other non-urgent information. In this paper, we developed a novel and simple network architecture, in which sensor information is classified into three traffic classes and each node activates one or more(More)
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