How to programmatically call in Android without the user noticing?

Question

Android

I work in mobile development, Android/IOS.
Recently I came across the question of how you can make a call in Android and immediately remove the standard Call Activity somewhere in the background.
I tried the solution, it works, although it's crooked. The time for which you need to set the timer jumps a lot, even within the same device.
Of course, the inner paranoid immediately woke up. The scenarios described in the question are pretty harmless. Rather for ease of use. But it is easy to understand that a long call without the knowledge of the user can easily hit, for example, in the pocket.
Therefore, the question is, how can you make a call from the application as discreetly as possible from the user, or even so that he does not notice at all?
And, if such a solution is found, then what needs to be entered into the demon, which would intercept it and beat it on the hands?
Maybe someone has experience?

Answer 1

Try to google for the phrase "android ril"
habrahabr.ru/post/183984

Answer 2

Here's something else - stackoverflow.com/questions/8307256/how-to-make-a-...