The Wireless Drain
By default, Ubuntu’s NetworkManager service is configured to aggressively scan for available Wi-Fi networks in the background, even when you are already securely connected to a router. It does this to quickly populate the network dropdown menu when you click the system tray icon, ensuring the list of nearby SSIDs is always up-to-date. However, this continuous background polling can cause micro-stutters during online gaming, drain laptop batteries slightly faster, and create unnecessary radio interference in dense wireless environments like apartment buildings.
Disabling Background Polling
If you primarily use a desktop computer or if you connect your laptop to the same network every day, you can force NetworkManager to stop scanning the airwaves in the background. You must edit the network configuration file using a terminal text editor.
Open your terminal (Ctrl+Alt+T). You will need to edit or create a specific NetworkManager override file. Type the following command and press Enter: sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf. When the text editor opens, you will likely see a section labelled [connection]. You need to add a new line immediately below it to explicitly disable the background scanning. Type exactly: wifi.bgscan=empty. Press Ctrl+O then Enter to save your changes, and Ctrl+X to exit the editor. Finally, you must restart the network service to apply the new rules by typing sudo systemctl restart NetworkManager. Your wireless card will now only scan for networks when you explicitly open the Wi-Fi menu.