Design and implementation of a sensor network node for ubiquitous computing environment

"Smart" and "attentive" services using users' context are going to be realized in future ubiquitous computing environment. Sensor network is receiving considerable attention as one of the key technologies to keep track of the users' context in the real world. Conventional sensor network research mainly aimed at environmental monitoring. However requirements of the sensor network infrastructure for ubiquitous computing is different from the one for conventional environmental monitoring. We have developed a sensor network testbed named "U³" to investigate issues that could arise when developing novel applications in a ubiquitous computing environment. U ³ is a wireless sensor node that is capable of communicating with other nodes to carry sensing data and queries issued by users. In this paper we describe hardware and software architecture of U³ and present the performance evaluation of a sample application developed on U³.