How can I check for 3G, wifi, EDGE, Cellular Networks in Windows Phone 7 using C#?
Unfortunately the api's don't provide very limited information about the kind of network connection you have. You can tell if you are on 3G, Cellular or Ethernet (i.e. USB connection to PC) but that is all the information you get.
Check out this for more info Better way to check for an network connection on WP7