An integrated gateway for various PHDs in U-healthcare environments

We propose an integrated gateway for various personal health devices (PHDs). This gateway receives measurements from various PHDs and conveys them to a remote monitoring server (MS). It provides two kinds of transmission modes: immediate transmission and integrated transmission. The former mode operates if a measurement exceeds a predetermined threshold or in the case of an emergency. In the latter mode, the gateway retains the measurements instead of forwarding them. When the reporting time comes, the gateway extracts all the stored measurements, integrates them into one message, and transmits the integrated message to the MS. Through this mechanism, the transmission overhead can be reduced. On the basis of the proposed gateway, we construct a u-healthcare system comprising an activity monitor, a medication dispenser, and a pulse oximeter. The evaluation results show that the size of separate messages from various PHDs is reduced through the integration process, and the process does not require much time; the integration time is negligible.