Wake up the app even if it is not running in the background

This shouldn't be the first question on the matter, but after reading a lot of articles and docs, I still doubt the possibility.

According to Apple document .

Preservation and restoration of the state
Since state save and restore is built into Core Bluetooth, your application can take part in this to ask the system to save the state of your applications in the center and peripheral managers, and continue to perform certain Bluetooth-related tasks on their behalf, even if your application is not longer. move. When one of these tasks completes, the system reloads your application in the background and gives your application the ability to restore its state and handle the event accordingly. In the case of the home security application described above, the system will monitor the connection request and restart the application again to control the central manager: didConnectPeripheral: delegate callback when the user is back home and the connection request is complete.

Does this mean that we can wake up the application even if it is not running in the background? and on what BT event and code implementation can we wake up our application and run it in the background?