i want to know whether Wi-Fi overrides mobile data connection in 8.1. which one is in use when both are turned on?
Yes. Wi-Fi overrides mobile data when you are actually connected to a Wi-Fi network. Otherwise, if you are not connected to a Wi-Fi network (even if Wi-Fi is turned on), or your Wi-Fi connection is limited, then the phone will revert to mobile data.
Is there a way to stop this? I don't want my Internet to work if my WiFi is down.
Is there a way to stop this? I don't want my Internet to work if my WiFi is down.
There is a setting under cellular that "for limited wifi connectivity" that will allow you not to use cellular data. I think it appeared in GDR3
Yes.
Settings > cellular+SIM > For limited Wi-Fi connectivity: don't use cellular data
You can turn your cellular data off here too.
unable to find that settings. i am using WP 8.1 DP
its still missing. that must have been changed in the WP 8.1