| 摘要 |
There is provided a monitoring system for monitoring a plurality of mobile devices at a server, the system comprising the server and the plurality of mobile devices, the plurality of mobile devices including a first mobile device, the system configured such that:(i) each mobile device acquires location data; (ii) each mobile device sends the acquired location data to the server via a telecommunications network; (iii) the first mobile device is operable to provide a first message to the server which indicates a high alert level from a user of the first mobile device, and (iv) the first mobile device is operable to provide a second message to the server which indicates a lower level of alert from a user of the first mobile device than the high alert level. |
