I assume it would be effective just like other vendors who have a firewall built in. I do not use public networks so i cannot say for sure but Bitdefender's firewall seems to have a stealth option in settings.
SETTINGS
Users can now enable and disable Stealth Mode and Paranoid Mode from the Settings tab.
• In Paranoid mode, alerts are shown each time an application tries to connect to the internet. When Paranoid mode is turned on, the Autopilot and Profiles features are automatically switched off. Paranoid mode can be used simultaneously with Battery Mode.
• Stealth mode establishes whether you can be detected by other computers. Click the Edit stealth settings to choose when your device should or should not be visible to other computers.
Users can also choose a default application behavior, which will allow Bitdefender to apply automatic settings to applications with no defined rules. Click Configure applications to choose whether automatic settings should be applied or not.