[Update: Toggle coming in Q Beta 5] Android Pie’s throttling of Wi-Fi scans is crippling some network tools
Android Pie is still fresh on everyone’s mind and we’re only starting to experience some of the changes that Google has made with its latest update. Android has always been criticized for having poor battery life compared to other mobile operating systems, but this was a double-edged sword. Sure, Android used more battery life than others, but it allowed for a lot more unique and diverse applications to be exclusive to the platform. Google has done a lot to help improve the overall battery life usage on Android, but this latest change to WiFi scanning is interfering with a number of network applications.
So, with the introduction of Android Pie, Google has put a limitation on the frequency that an application can use the platform’s WiFi Scanning feature. Google has responded to the report in their issue tracker and confirmed this latest update to Android limits this functionality for both foreground applications as well as all background applications. For foreground applications, the feature is limited to 4 scans every 2 minutes while applications in the background are restricted to only 1 scan every 30 minutes.
On the surface of it all, this seems like a decent way to alleviate some unneeded battery usage, but there are some circumstances where this has had a negative effect. For instance, popular network applications such as WiFi Analyzer and WiGLE (a Wardriving app) need more frequent access to the WiFi scanning than your standard application. This change has essentially made these types of applications useless as it reduces their scan rate by at least 30x even though they are active applications meant to be used in the foreground.
As you can see, these outlier circumstances have had a negative effect on some popular networking applications. Google has been active in this issue tracker thread and even went as far as to explain how the throttling is determined. As of right now, there hasn’t been a solution provided by Google themselves, but they have gone ahead and deferred this issue “for consideration” in a future Android release.
Update 1: Still in Android Q
According to a comment on the Google Issue Tracker (via AndroidPolice), Wi-Fi throttling is here to stay. However, Android Q allows users to turn off throttling on a local device with the following ADB command:
adb shell settings put global wifi_scan_throttle_enabled 0
Despite what the comment says, sending this command does not require root access.
Update 2: Toggle coming in Q Beta 5
A Google employee posted a comment in the Google Issue Tracker thread saying a toggle is coming soon. Starting with Android Q Beta 5, which is scheduled for Q3 2019, there will be a toggle to turn scan throttling off in the developer options. You won’t need to use the ADB command mentioned in the previous article update.