Electric Power Conservation Technology for Wireless Sensor Networks
Y. Kubo, Kentaro Yanagihara, Masanori Nozaki · 2009
Wireless networks comprised of sensors with wireless communication functions are called wireless sensor networks. Diverse research and development is being carried out for these networks, with applications anticipated for environmental monitoring, automated metering, structure monitoring and home security. Wireless sensor networks add wireless communication functions to sensors, comprise wireless multi-hop networks to broaden the scope of observations and make the installation process of the sensors easier. The requirements for such wireless sensor networks include battery driven operations and sensing periods that last over a long term, often lasting several years. Currently available wireless sensor network technologies, however, are restricted by the fact that the relaying sensor nodes are unable to be operated in an energy saving mode, thus it is difficult to operate battery driven sensor nodes over many years. Such restrictions narrow down the scope of application for wireless sensor networks creating a need for the development of a technology that enables all sensor nodes in a network to perform in an energy saving mode. People are becoming more and more aware of issues relating to the global environment and in such circumstances it is often said that it is important to understand the current status of the global environment. Wireless sensor networks have been considered for implementation as a means to understanding the current status. When environmental monitoring systems or energy conservation systems are being established using wireless sensor networks, the implementation of such systems may bring about an extremely high electric power conservation effect, but if electric power conservation of the system itself is not adequate or if wiring for the power source to the feed sensor nodes is necessary in order to install such electric power conservation systems, the value of such electric power conservation systems may be diminished. The electric power conserving technology for sensor nodes, developed through our research, converts nodes into electric power conserving types, conserving energy of the system itself and conserving electric power consumed by nodes, which made the wiring of the power supply to these nodes unnecessary, thereby improving the ease of installation. Therefore, this is expected to promote the popularization of systems for conserving energy using wireless sensor networks.