iphone SDK detect Wifi and Carrier network

Question

my app accesses the internet and i just want to detect whether there is a connection either via wifi or via carrier data network or not

apple has made an example for

Answer 1

These techniques are useful, but keep in mind that the device's path to the Internet might consist of several different types of connections. For example, a iPhone or iPod touch might be using WiFi to connect to a mobile hotspot, which in turn has its own 3G wireless connection. So it is not safe to assume that the presence of a WiFi connection implies higher bandwidth than 3G.