Answer.
Depending on how you have your TV connected to the Q Active Hub, there are different methods which can wake the Hub from standby.
If using HDMI (ARC), this connection type uses what are known as CEC (Consumer Electronic Codes), these are two way commands going between the two devices and include On/Off/Volume+/Volume-/Mute, the CEC commands can be turned on/off on the TV and are implemented under different names, here are some of the common ones
Panasonic - Viera Link
Samsung - AnyNet+
Sony - Bravia Sync
Please refer to the TV manufacturers instruction manual on how to turn them on/off.
If using the 'Digital Optical' to connect between the TV and Q Active Hub, the connection is sensed using the light from the optical cable. This method does rely on the TV manufacturer implementing optical circuit off when in standby, beware, some manufacturers do not always do this. To check this, attach a digital optical cable to the TV, put the TV into standby and check the unplugged end, if there's a red light present, the 'auto on/off' will not work.