Originally Posted by The U
huh. i guess maybe I never noticed. My phone appears to stay on for the duration of my call. I never made any changes to it. The only thing that DOES happen, is the screen turns off when the phone is up to my head, but it comes right back on when I take the phone away from my head. It doesn't actually go to sleep unless I hit the power button. I've used it multiple times for multi-hour conference calls at work. Mine is a Sprint HTC One. Wouldn't think it would be different for other carriers, but maybe it is.
That doesn't preclude there being some option for that, but I don't know what it is, and never set it. This was the default behavior from the first day I got my phone.
I wonder if it is related to what kind of lockscreen behavior you have? I don't use a password or PIN or anything to unlock. I just swipe to unlock. I know that a lot of times, if you sync to some Exchange servers, they can force security policies onto your phone. Several co-workers have that on their various Android phones. Even though they are personal phones, because they connect to the Exchange server, certain security policies are pushed down, one of which requires the use of an actual lock screen with PIN or password.