Today I made a completely unscientific, but still using somewhat of the scientific method in determining why there is data use when on wi-fi. There was an article shared on Facebook from The Theresa Dixon of The Plain Dealer newspaper in Cleveland by two of my friends and I just had to see for my own. NOTE: I am grandfathered into AT&T’s unlimited plan, so I don’t normally care about data limits. I tested with an iPhone 6S+ with iOS 9.
Here are my test scenarios and results:
- Wi-fi assist turned off but connected to wi-fi. Result: As soon as I got to one bar on the wi-fi, it turned to cellular data and I was charged. I was still on wi-fi two bars and higher. When my phone used cellular data, it said LTE at the top of the phone and not wi-fi.
- Wi-fi assist turned on but connected to wi-fi. Result: Same result as #1. Except, it still showed wi-fi at the top on one bar and sometimes two bars but was using cellular data.
- Phone in airplane mode with wi-fi turned on. (This is like what you’d do when on an airplane using the airplane wi-fi). Result: Pages would not load if I was not within wi-fi range. Pages loaded slower in low wi-fi range.
- Phone with cellular data turned off. Result: No cellular data. Can still make phone calls.
- Phone with airplane mode. Result: No cellular data. Cannot make phone calls.
I only tested on one phone in one location, but it appears to me that the iPhone uses cellular data with wi-fi assist on or not. The only difference appears that you’ll see the cellular data icon at the top of your screen and know you’re using data. My recommendation is to turn off wi-fi assist so you at least can see on the screen that you’re using data. I’d also recommend you turn off cellular data if you just want to use wi-fi data or just a cellular phone without data if you’re not on wi-fi.
To make changes to your settings, go to SETTINGS > CELLULAR on your iPhone. Cellular data is at the top of the page. Wi-fi assist and the reset button for testing is at the bottom. I hope this helps. Let me know if you have any questions.
Original article: http://www.cleveland.com/business/index.ssf/2016/09/verizon_data_overages_may_stem.html#incart_river_index