| 摘要 |
A device has a tag. The device is connected to the Internet and runs a web server. The device controls sensors or machinery. The tag encodes an URL whose address is the device. A person scans the tag with a mobile device, like a phone. The phone queries the server. The page sent to the phone lets her control various aspects of the device. The device lets a maximum number of users actively control it at the same time. Extra users go into a queue with a maximum length. When the queue is full, if the tag is active, it is turned off. The device can have several tags or speakers distributed over different locations, where the speakers emit audio encoding an URL giving a similar control of the device. A tag can be reconfigured if the device changes its Internet address. Or the tag can be periodically reconfigured to favour giving control to users who are currently near it. The URL format can be used by the phone to decide not to make a wireless query to the server. Saves energy on the phone. |
