%0 Journal Article
%T A Three-Tier Architecture for User-Centric Ubiquitous Networked Sensing
%A Jin Nakazawa
%A Hideyuki Tokuda
%J ISRN Communications and Networking
%D 2012
%R 10.5402/2012/637134
%X In a sensor network, sensor data are usually forwarded from sensor nodes to a database. This tight coupling between the nodes and the database has been complicating user-centric applications that traverse multiple different sensor networks. To break this coupling, thus enabling user-centric applications, we propose a three-tier architecture for ubiquitous networked sensing. Its major feature is that it contains the ¡°core¡± device, which is assumed to be a terminal held by users between sensor nodes and sensor databases. This architecture supports the sensor data directly transmitted to and consumed by the core device, in addition to the classic ones that are transmitted to the sensor database first, and downloaded to the core. The major contribution of this paper are the following three-fold. First, we clarify the architecture itself. Researchers can leverage the architecture as the baseline of their development. Second, we show two types of prototype implementations of the core device. Industry is allowed to develop a new product for practical use of ambient sensing. Finally, we show a range of applications that are enabled by the architecture and indicate issues that need to be addressed for further investigation. 1. Introduction The recent research and productization of wireless sensor nodes have been enabling ubiquitous networked sensing environment where sensor nodes are densely embedded around users in homes, offices, parks, roads, and so forth. For example, home owners would manage their own sensor networks [1]. A university campus can install its own campus sensing network [2]. Opposing to the node-side, technologies towards sophisticated sensor database have been deeply investigated. Usually, sensor data are directly forwarded from sensor nodes to a database. In the above examples, there would be a sensor database at the home and the campus to store the data captured there. These two sides, sensor nodes and sensor databases, thus form a tightly coupled networked sensing architecture. This tight coupling has been complicating user-centric applications that traverse multiple different sensor networks. For example, suppose an application that records aerial pollution in the places where its user visits. Since aerial sensors are not small, it is not practical to assume that the user carries the sensors. This application thus needs to acquire data from the aerial sensors around the user. With the classic tightly coupled architecture, the application is required to identify the databases where the aerial pollution data are stored and query for the
%U http://www.hindawi.com/journals/isrn.communications.networking/2012/637134/