Background Location updates using Google API - Fused Location Provider not accurate

Question

I have been working and testing on background location updates using GoogleApiClient for Interval and Displacement based updates. On testing and analyzing for a few days I figured out some variations in the output which I did not expect.

1. While using setInterval and setFastestInterval for Interval based updates, say I have set an Interval as 15 mins and Fastest Interval as 10 mins , 90% of the time I am getting updates in the expected Interval (10 to 15 mins). But sometimes I noticed that the updates take much longer time than the specified Interval, like, the difference is around 30 mins and 60 mins. Any Idea about why is the difference?

2. While using setMinimumDisplacement for Distance based updates, say I have set a Displacement as 200 meters , I am getting updates only on stationary points (While travelling it doesn't give updates even if it is more than 200 meters) which are 200 meters and above. Is this how it works normally?

I am using PendingIntent type of location requests in order to receive location updates in BroadcastReceiver for location updates in background.

fusedLocationProviderClient.requestLocationUpdates(locationRequest, pendingIntent);

While testing, the Location Services were ON and Location Mode was HIGH_ACCURACY .

Answer 1

Please refer to the documentation to get the proper behavior of LocationRequest API.

LocationRequest Api documentation

From this documentation:

• Applications cannot specify the exact location sources, such as GPS, that are used by the LocationClient . In fact, the system may have multiple location sources (providers) running and may fuse the results from several sources into a single Location object
• Location requests from applications with ACCESS_COARSE_LOCATION and not ACCESS_FINE_LOCATION will be automatically throttled to a slower interval, and the location object will be obfuscated to only show a coarse level of accuracy.
• All location requests are considered hints, and you may receive locations that are more/less accurate, and faster/slower than requested

For more detail description read full documentation from above link.

Hope this explanation may help you.

Answer 2

I have found the answer to my second question. Documentation says that it's not recommended to setMinimumDisplacement to 0 but that's the actual trick. It works as expected when it's set to 0.

It's works correctly when having two different LocationRequest s (Based on Interval and Displacement) so that one's setting does not affect the other.

A Foreground Service is preferred for the above scenario so that the location updates doesn't get killed by the OS.