Different iPhone 5 owners are complaining about slow or inconsistent Wi-Fi connection. In some cases, the iPhone 5 Wi-Fi connectivity download speeds managed to reach few kb per second. what is causing this problem is not known at the moment: in some cases it seems to help to switch from WPA2 to WEP security on a wireless network, but this encyption methode is much less safe. In addition, this trick does not seem to work for everyone
How large the Wi-Fi problems occur is not yet clear. On both the MacRumors forum and the official Apple support forum several people complaining about the issue and some reported that a replacement phone solved the issue. A visitor to the Apple support forum says Apple Care aware of the problem and the slow download speeds and WPA2 problems seem related software according to their part, while problems connecting via Wi-Fi can be caused by hardware. Apple has not officially responded. Do you suffer from Wi-Fi problems on the iPhone 5, we advise you to contact Apple.