Thread: Question re Iphone

When on WiFi the "3G" up in the top left is replaced by the WiFi symbol (a series 4 curved lines - almost triangular)

A '3G' sign for internet, or a curved fan shaped sign for wi fi at the top of the screen.
Don.

As the above answers. But you can also turn off cellular data temporarily when purely surfing the web at home, so that even if your WIFI signal dropped out, you wouldn't be using your iPhone's data allowance. You obviously not be able to make/receive calls however.

This is easily found in Settings - General.

As long as your WIFI signal is stable, this is unnecessary - but as an example, depending on how far away from my router I am, my WIFI signal can drop out momentarily and then any web use then gets pulled from my phone's data allowance. Just something to consider to cover all possibilities here.

I've had 3G data get used from my 4s overnight even though I was asleep, the phone was not in use, and wifi was active. This seems to be a pretty common problem if a google search is any indication.

I've since closed off all the apps using the apps switcher (double click home button), and I played with the cellular settings. It seems to have stopped mystery data use.

You probably should download a free data monitor app so you can check on it daily. You can set the date a billing period starts and it will reset the counter automatically. Most also allow you to set notifications at specified data usage levels. Alternatively the phone has its own cellular usage counter, but it must be manually reset on the 1st day of each billing period.