my Mac mini did wake up but remained 'Offline' on Teamviewer ...
I tried to wake up my Mac mini via a public address, and it seemed that I did succeed because the power light of my Mac stopped flashing and turned into a steady light.
But my problem is: when my mac woke up, it remained 'Offline' on the TeamViewer app in my iPad, if I hadn't pressed any key on my keyboard or clicked my mouse, my mac will go back to sleep very soon.
If I did press a key while my mac woke up, it would change its state from 'Offline' to 'Online' immediately on the TeamViewer app, and then I could remote control my mac without any problem. But this is not something I can do while I am not at home ^_^.
Under such circumstances, I can't remote control my mac over the internet in any way.