As stated clearly in Apple docs, beacon ranging can be done in background for a short period of time only, say up to 10 seconds by default or up to 3 minutes with the help of background task expiration handler. As per my app's use case, app needs to do beacon ranging for every 15 mins until user exits the region. I am thinking of using background push notification(silent push notification) for this purpose(assuming data connection is available on the device always). So the flow goes like this, upon user entering the region, app calls the server with device token, server sends silent push notification for every 15 minutes. Once app received push notification, it does beacon ranging within allowed period of time if needed. Question I have here is whether using push notification in background mode to do ranging is legal, will I face any issues during app store submission.
Note: Also I need to enable BLE background mode for the app, to read some characteristics from some BLE devices.
If you misuse one of the background modes, the app will probably be rejected, saying that, I don't think silent push notifications were meant for: keep an iOS app in "Background" state by sending it a silent push notification every few minutes.
another thing is that silent push notifications are rate limited as described http://asciiwwdc.com/search?q=push+notification, so I'm not sure if they will be sent every few minutes.
Apple says that;
Silent notifications are not meant as a way to keep your app awake in the background, nor are they meant for high priority updates. APNs treats silent notifications as low priority and may throttle their delivery altogether if the total number becomes excessive. The actual limits are dynamic and can change based on conditions, but try not to send more than a few notifications per hour.