1. Field of Invention
The present invention relates to a remote wake-up technology in mobile communication system, in particular, to a remote wake-up system based on a WWAN (Wireless Wide Area Network) module, a WWAN module and a terminal.
2. Description of Prior Art
Connections between mobile terminals, such as mobile phones and notebooks, and Internet are becoming more convenient with the continuous development of mobile communication technology. With plugging of a communication card, i.e., a WWAN module (such as a wireless network card for GPRS, CDMA or 3G) to an interface in a notebook (such as a USB, a PCMCIA/Cardbus or a MiniPCIE), mobile networking in the notebook can be achieved. In addition, a SMS (Short Messaging Service) and a phone call can be carried out by the notebook.
As can be seen, a WWAN module is becoming a part of a standardized configuration of a notebook. Nowadays, a series of applications arise which remotely wakes up or starts a notebook using a WWAN module. There are many approaches for remotely waking up or starting a notebook using a WWAN module, the basic methods of which, however, are all based on a detection of the fluctuation of working current of the WWAN module.
However, the accuracy and stability of this method is rather poor. Generally, the reason is that the WWAN module itself will periodically search for base station during its sleep state, and its working current will increase during the search, which may cause the misoperation of waking up a terminal by the WWAN module. Also, this misoperation may occur due to a change in a power supply of the terminal or an external electromagnetic interference.
Additionally, the security of this method cannot be guaranteed. A power-on or wake-up signal will be generated once a phone call or short massage arrives, regardless of whether it is an actual power-on or wake-up signal. That is, there are no actual security validations on these signals.
Therefore, it is a technical problem to be solved how to provide an accurate and secure remote wake-up system based on a WWAN module and such a WWAN module.