Currently Being ModeratedNov 11, 2012 6:32 PM (in response to aggiechen)
If this is just with your home WiFi reboot your router by turning it off for a few seconds. If there are additional symptoms please post them to aid in the diagnosis.
Currently Being ModeratedNov 11, 2012 7:12 PM (in response to Lawrence Finch)
It is my home network, has been intermittently total to reconnect wifi to Internet, but my wife the iphone4 is good can connect to the Internet, she is iso5.0.1 version
Currently Being ModeratedNov 12, 2012 3:21 PM (in response to aggiechen)
Have you rebooted your router yet?
Currently Being ModeratedNov 12, 2012 3:41 PM (in response to Lawrence Finch)
Rebooting the router makes a huge difference. Apple made some changes to how the iPhone connects to a wifi network in iOS 6.0 and 6.0.1 as well. Hopefully in iOS 6.1 they will get the changes to actually work. In the mean time you have to reboot the router to get it to pick up the latest ip address from your provider. I did this at home and my phone, 4S running iOS 6.0.1, connects no problem. At work I need to really fuss with my phone to connect to the network. They tell me that they have restarted the routers on a regular basis, but as I mentioned it is a royal pain to connect and stay connected.
They seem to have also set the firmware up so that when you put your phone to sleep/locked wif disconnects. So if you are doing a wifi download you need to chang the autolock settings to never and plug your phone in.
Currently Being ModeratedNov 12, 2012 3:51 PM (in response to Thom_D)
WiFi has always disconnected when the phone goes to sleep, unless it is plugged in. All iPhones have done this for the 5+ years iPhones have been around. If you don't believe me you can search older threads that describe this behavior, such as this one: https://discussions.apple.com/thread/2450738
Rebooting the router solves a router problem - most cheap routers have flakey DHCP server daemons. That's the app that assigns IP addresses. Eventually the DHCP server dies, and stops assigning IP addresses. This doesn't affect devices that are continuously connected like other computers on your network, but the iPhone, which connects and disconnects several times a day eventually times out its lease and needs a new IP address. If the DHCP server in the router is not running it can't get one. The symptom of this problem is when you open Settings/WiFi and tap on the arrow to the right of the network name the IP address will beging 169.254, the self-assigned IP address range reserved for ad hoc networks.