I have an iPhone 4 with iOS 6.1.3. I turn on cellular data + 3G and Wi-Fi constantly.
I was at a site office today and my iPhone automatically connected to the office's Wi-Fi. The tech guy was not around to provide me with the Wi-Fi password to use on my Windows laptop. I then connected my iPhone to my Windows laptop using the USB cable and turned on Personal Hotspot on my iPhone.
At that point, is my laptop using cellular data through iPhone, or the Wi-Fi access point my iPhone is connected to?
I noticed that my iPhone has the 3G symbol in the status bar. But when I disconnect the cable from my laptop, it switches to Wi-Fi.