It appears that most of the times it dropped WiFi to 3G was coming out of sleep mode (and perhaps a couple of times going into sleep mode). When coming out of sleep mode, it sometimes immediately captures the WiFi again and sometimes it takes a couple of minutes before reconnecting to WiFi. There has also been a few times I have been holding the phone and it switched from WiFi to 3G and I laid it down for a couple of minutes and it went back to WiFi, but I don't think that has happened often but I am keeping an eye on it because I don't want to send or receive a big file on 3G when I could be on WiFi.
My iPhone 3G is doing the same exact thing. It looses the wi-fi every five minutes. It, always comes up either saying, incorrect password, or just asking me to join it all together.
It, never did that while I was living with my parents and now since I've moved it's happens all the time.
Sometimes I can hit cancel and hit our network name and it connects that way, but other times I have to re-enter the password to get it to log back on to the wi-fi.
It is really frustrating me.
I reset my network settings but that doesn't help.
Are your house phones cordless? Are they 2.4 GHz? Many cordless telephones work on the exact same frequency as wifi.
I used to have an issue where whenever my landline cordless phone would ring, my wifi would drop on all the devices in the house.
There is 1 wireless house phone (don't know the frequency) but no wireless business phones or headsets at work. Today at work, I noticed it taking a while to go from 3G to reconnect to our Wi-Fi. It eventually switches over but seems to take longer than it should considering I am 10-15 feet from the transmitter and not moving around the building with the phone, etc. Since the iPhone 4 has antennae issues for phone calls, I wonder if other parts of the antennae have problems connecting to WiFi if you touch a certain part of the antennae?
I have been having some issues with the iPhone 4 and Wifi on my home systems.
My Orange 2G connection (don't get 3G here at all) is weak and the phone drops from 5 bars (IOS 4.0.1.) to Searching with depressing ease, somewhat reduced now I am keeping it in a case.
When my iPhone 4 goes to 'sleep' for 5 mins or more and is woken up it does not re-establish a wifi connection for up to 4 minutes. Checking Settings Wifi shows it is connected to the router at full strength signal. (not surprising considering the router is 2ft away from it). The connection details revealed it had no IP address DNS Gateway etc etc.
The router is a Draytek Vigor 2820Vn.
The problem could also be repeated on a TC with all the latest updates.
After, many many hours of diagnosis with Apple then Orange and then back to Apple it was decided to swap the phone out.
I am still seeing the same problem, need to do more testing to determine if it is consistent.
I'll update in a couple of days.
The best is was doing was re-connect
My wifi does this constantly at home and at work. It says connected but i cant access anything online, i can go to settings and kill the wifi and reconnect and it works everytime within a few seconds, dont know why it goes to sleep or whatever it is doing but its annoying for sure.Note that i can be on the phone or have used the pone within a minute or two when this is happening so it reallyshouldnt be in "sleep" node.
The post after my initial question made some sense--that the iPhone is saving some battery life going from WiFi to 3G when it goes to sleep mode. There are many times when the phone goes back immediately to Wifi from 3G when coming out of sleep, but there are times when it takes a while for it to re-connect to Wifi and it is usually when I really need to use it, which is probably why I noticed it in the first place. Over the last week or so, I have been testing the connection coming out of sleep mode and it seems to be a little better at going back to Wifi out of sleep.
By the way, I am not using a case on my phone yet. The one I wanted was out of stock. I will be interested to see if the connection to WiFi out of sleep mode is perfect once I get my case.
At first, I thought it might be the antenna on the stainless steel band around the phone (similiar to the problems with phone antenna). But the issues I have had with the Wifi hasn't been when I am holding the phone; it's been laying flat on my desk. Has anyone called Apple about it? I thought about it but haven't yet. Does Apple read the forums?
"Forget this network" doesn't have any real effect.
Neither does "Reset Network Settings"
Neither does "Restore to Factory"
Neither does "Replace iPhone"
Tried them all.
Having said that I tried setting the DHCP server to Bind iPhone MAC address to an IP address seems to have reduced occurrence of the problem, still testing.
Glad to see others have this problem. Issue I have is when iphone 4 charging at night close to the wifi, it seems to be fine. Yet as soon as I take it out of sleep and walk around the house, I get data charges. Either it's loosing the wifi connection, or AT&T is bypassing it and sending data directly to the phone. Arrived at our house in Maine yesterday afternoon. TURNED OFF DATA CONNECTION, AND HAVE NOT GOT DATA BILLS SINCE. Wifi works perfectly, I have checked my computer, and have received all my e-mail messages. I'd be interested what happens in your case if you turn data connection off in your home. I will test this as well when I return to Boston.
I have the iPhone 4 and upgraded to 4.0.1, while my wife has the iPhone 4 but has not upgraded. Never had wifi issues before in our house with the 3G, but now there are spots in the house with no coverage.
But what makes it weirder is that her phone has no problems picking up wifi in the same place in our house where I get no signal. Holding the phones right next to each other and she has a signal and I don't.
It's getting a bit annoying, and I have been looking online to see if others have the same issue and this thread is all I've found