The Android Wi-Fi framework helps users connect to a good Wi-Fi network when networks are available and needed. Android does that in two ways:
- Turn on Wi-Fi automatically: Re-enabling Wi-Fi when the user is near a previously saved network
- Notify for public networks: Informing users about available good open Wi-Fi networks
The features described are implemented by AOSP code and you don't have to explicitly enable or configure them.
Turn on Wi-Fi automatically
Users may disable Wi-Fi for a variety of reasons (e.g. a connection to a bad network) and can then forget to re-enable it when arriving back home, resulting in a bad experience (e.g. not being able to control home automation devices). The Turn on Wi-Fi automatically feature, introduced in Android 9, solves this issue by automatically re-enabling Wi-Fi whenever the device is near a Wi-Fi network that is both a saved network (i.e. one which the user explicitly connected to in the past) and has a sufficiently high RSSI.
The feature can be enabled or disabled by the user using the Settings app at:
Settings > Network & internet > Wi-Fi > Wi-Fi preferences > Turn on Wi-Fi automatically
Figure 1. Turn on Wi-Fi automatically feature.
Wi-Fi Scanning (for Location) must be enabled for this feature to function. If Wi-Fi Scanning is not enabled the user is prompted for permission to enable it. Wi-Fi Scanning is required because scan results are used to determine whether the device is in the vicinity of a Wi-Fi network that meets the criteria to re-enable Wi-Fi connectivity.
The feature avoids re-enabling Wi-Fi immediately after a user disables it, even if the device observes a saved Wi-Fi network of sufficient quality. For example, if the user is in the office and is connected to the office Wi-Fi (a saved network) and then disables Wi-Fi, the feature won't re-enable Wi-Fi until the user arrives at a different environment with a different saved network that meets the re-enabling criteria.
Notify for public networks
The Open network notification feature raises a notification to the user whenever:
- Wi-Fi is enabled
- The device is not connected to a Wi-Fi network
- A Wi-Fi network that is both open and has a sufficiently high RSSI (the same RSSI threshold as used by the internal Wi-Fi selection algorithm) is available
The feature can be enabled or disabled by the user using the Settings app at:
Settings > Network & internet > Internet > Network preferences > Notify for public networks
Figure 2. Notify for public networks feature.