| 摘要 |
<p>A communication system (18,19,21) has a server which prompts a user selection of a response from a set of candidate responses, and downloads a message to a user device according to the selection. The server sends an instruction to the user device (19) to generate a message containing at least some of the contents of the downloaded message, including a control command derived from the user selection. The device (19) generates an upload message with at least some of the contents of the download message and also additional data (h) and the control command. The upload message is processed by the server (18) to perform an activity. The server may include one of a number of possible return paths for the upload message, and indeed it maybe to an access controller to open a barrier. <Figure 1></p> |
