Tetsuya Kawai

Learn More
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)
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)
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)
— In wireless sensor networks used as a social infrastructure , urgent information, such as a fire alarm, is needed to be transmitted as fast and reliably as possible. In this paper, we propose design methodology for a sensor network which provides preferential control of urgent information over other non-urgent information. In our methodology, several(More)
In a wireless sensor network used as a social infrastructure, priority control is essential to prefer transmission of urgent information over other non-urgent information. In our previous report, we proposed UMIUSI (aUtonomous Mechanisms Integrated for Urgent Sensor Information) architecture, in which several simple mechanisms are combined to enable(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)
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)
— A fast and reliable transmission mechanism of urgent information is essential for establishing a wireless sensor network infrastructure for a safe and secure living environment. In this paper, we propose a transmission mechanism where high reliability and low latency in transmitting urgent information are achieved by making an " assured corridor " where(More)
  • 1