If you have an iPad third generation / iPad with Retina display and 30pin Sync port then you can in fact activate internet tethering.The trick is described her:http://forum.ifun.de/threads/54799-iPad-(3.-Gen.)-Internet-Tethering-mit-Simyo/page2

• Make Sure you have at least iOS 6.1
• Go to: Settings > Cellular Data > APN Settings
• You should see two sections: "Cellular Data" and "Internet Tethering"
• Make sure in both sections there is just the following entry:
• internet.eplus.de
• (no additional passwords etc.)
• Then even tethering should work (exit settings app) .. go into Personal Hotspot activate personal hotspot and connect with a device of your choosing. The top bar should color blue. If that does not work immediately check APN settings again exit settings app again and try hotspot feature again.