Push notification enable server side send data to client side without client request.
However, I want an opposite way.
I want the client side send data back to server by regular time, even thought client side doesn't activate the mobile app.
I searh this function for long time. Is there any existing function can help?
You should use the Android Services for this. You can use AlarmManager system service to schedule your service to run at specific intervals. Check the tutorial below. http://www.vogella.com/tutorials/AndroidTaskScheduling/article.html
Hope this helps -Raghu