Dynamically updatable UPnP service for device role management

UPnP is a networking protocol that allows devices embracing personal computers, smartphones and tablet computers to discover other devices and control their services. Using portable smart devices, the UPnP services needed by these devices often vary. According to the locations or the situations of users, the required roles of the devices that support users´ activities change and the services needed for achieving the roles also vary. However, it is difficult to dynamically add or update UPnP services and change the roles of the devices. We propose a new dynamic update method of UPnP services in this paper. `Service-updater service´, one of UPnP services, is utilized in this method, which can update other UPnP services of its own device. Users do not have to install many services manually in advance. In addition, applying our method, it is also possible for smart devices to change their roles; according to users´ situations, the devices can be turned into UPnP controllers, which control UPnP services of other devices. We have developed a prototype to which this method is applied and we have confirmed through the experiment that this technique effectively supports users´ activities.