Associating users and devices using attention-correlated communication
Kurt Partridge, Gaetano Borriello · 2005
Traditionally, a computer operating system supports its applications by providing several common services. The set of services typically includes mechanisms for storing user-specific customization information and for performing coordination between applications. But customization and coordination are typically not supported in embedded devices and appliances, because these systems have no way to appropriately identify the user. This dissertation investigates how embedded systems can support customization and coordination using a new approach, called user-device association, which is implemented by a new technique called attention-correlated communication. With user-device association, information about the user is automatically communicated to a device when that device is used. This information enables customization and coordination without performing identification, thereby better preserving users' privacy. This dissertation makes four contributions to user-device association. First, it presents the results of a survey of potential users. The results show broad interest in user-device association applications, and respondents' willingness to regularly wear the devices required for them. The second contribution is a model of system architectures that support user-device association applications. One architecture, Facile, is implemented and described in detail. The third contribution is an in-depth study of body-coupled communication, which uses imperceptible low-power electrical signals to send data through the human body. This study includes an implementation that set a new data throughput record when it was originally published (though it has since been superseded). The study also identifies design parameters that affect whether body-coupled communication is well-correlated with touch. The final contribution is an experiment measuring performance of three user-device association mechanisms on two applications. The experiment shows that for these two applications, users could complete tasks faster than they could manually. The post-experiment interviews also identify several design issues for user-device association systems. This work concludes that user-device association is viable, and that although many physical communications media are suitable, in the short-term RFID provides the best physical-layer communication mechanism.