title: Detect GPS in iOS device with CoreTelephony
body: <p>I was looking for a way to detect whether an iOS device has a GPS unit or not, and I ran into <a href="https://stackoverflow.com/questions/2004689/detect-gps-hardware-in-iphone">this question</a>. I found the last answer very interesting:</p>
  
  <pre><code>CTTelephonyNetworkInfo* netInfo = [[CTTelephonyNetworkInfo alloc] init];
  if(netInfo) {
      CTCarrier* carrier = [netInfo subscriberCellularProvider];
      if([[carrier carrierName] length] &lt;=0) {
          //NO operator=&gt;NO 3G and no real GPS  
      }
  }
  </code></pre>
  
  <p>I was looking for some confirmation as the the validity of this technique/whether or not it is entirely accurate. I don't have enough devices to test it myself.</p>