Turning Your iPhone Into a Virtual Routerby David Weedmark
As long as you have cellular access and a service plan that allows it, you can use your iPhone as a virtual router so you can access the Internet from your computer or other device like a tablet. To access this feature, turn on the Personal Hotspot in the iPhone's settings. If the feature is not listed, your service plan doesn't include it. Contact your cell phone provider to find out how you can get it.
Using the Personal Hotspot
Turn on the Personal Hotspot feature by tapping "Settings," selecting "General," and then tapping "Cellular." If Cellular Data is off, tap the toggle to turn it on. You can then tap "Personal Hotspot" to turn it on and off. When a computer or other device is using the iPhone's Personal Hotspot, you see a blue band at the top of the iPhone screen. If you are connected to it with other Apple iOS devices like an iPad or iPod Touch, you see a Personal Hotspot icon in the status bar of that device.
When you activate the iPhone's Personal Hotspot, it automatically generates a password and displays it on the screen; enter this password on your computer or any other device trying to connect to the iPhone as a virtual router. To change the password, tap it on the Personal Hotspot screen to be prompted to enter a new password. Your password must be at least eight characters long.
Wi-Fi is just one way to access the Internet through the iPhone's Personal Hotspot. To connect to the iPhone using Bluetooth, first activate Bluetooth on your computer or other device, and then turn on Bluetooth on the iPhone through its Settings menu. You can also connect the iPhone to your computer using the USB cable it shipped with. Doing so makes your iPhone visible as an option in your computer's network preferences.
Using an iPhone as a virtual router can quickly drain its battery. Connecting it to a wall outlet or your computer can ensure that the battery stays charged. Using cellular data service to access the Internet can also take a toll on your wireless service bill, especially if you are streaming video or downloading files. Your iPhone can tell you how much cellular data has been streamed in its Settings: go to the General settings, select "Usage," and then tap "Cellular Usage." You can tap the "Reset" button at any time to put the data counter back to zero.
Information in this article applies to iPhones running iOS 6. It may vary slightly or significantly with other versions or products.