The Wi-Fi network is activated per default on a b-box 3. Turn off your Wi-Fi network and turn it back on by keeping the on-off button > next to the Wi-Fi LED pressed for 3 seconds.
If you look at the front of your b-box 3 modem, you will see that the Wi-Fi LED indicator has gone out. This confirms that the Wi-Fi network is now disabled.
How to deactivate or reactivate Wi-Fi