So I was searching about this problem today and here is a forum deidcated to it. Hopefully 2 days till iOS7 and we will be OK.
I got my son an iPhone 4S a couple of weeks ago and noticed his seems to have connection issues, yup, his wifi is dropping out when the screen is locked.
Now, I have a 4S also, from 2012 and I DO NOT have this problem. Perhaps I have more things that are keeping my connection alive?
It frustrates me because the 4S also has the problem where when you leave wifi the 3G disconnects, which then you have to go to Airplane mode and toggle off/on to restore (not all the time, but enough).
Two phones, one has the issue and one does not.
Tried many of the tricks here without much resolve.
I take that back....I see now if it is unplugged the connection goes to sleep..what I do not understand then is why my sons phone seems to be slow with iMessage and stuff when he is home unless he is just bouncing between Wifi and 3G. This would theoretically mean he could not get Facetime when his phone is locked, that stinks.
IOS 7 *****! 1) the battery drains faster than before. 2) wifi disconnects when screen is locked. for issue number 2, prior to ios 7,my 4s didn't experience that problem. now,my imessages get delayed and i can't be contacted cia facetime unless i press my phone.
wth apple?! i bet android users don't experience issue #2.
please apple, send a fix for ios 7. please respond to the needs of your users. we need to be connected even if our phone's asleep (and disconnected from power). i was happy with my 4s until i updated to ios 7 (which i'm regretting now).
I suggest actually reading messages in a thread that you post a message to. The answer has been repeated many times in the thread.
All iPhones, since the beginning of iPhone time (June 27, 2007), have turned off WiFi when the screen is locked to preserve battery life. If you want WiFi to stay active when the screen is locked connect the phone to power.
i found a solution to the wifi problem! i noticed that in some routers,my 4s (running ios7) DOESN'T disconnect when locked. what i did was, in my linksys basic wireless settings, i switched it to manual wireless configuration and i changed the wifi signal name from the default "linksys" to a unique name.
i surely hope this works for everyone.
of course prior to this discovery,i did the reset network settings countless times. maybe you should do that first before you try my router method.
I think I've found the solution, as you'll seee below.
At work, my phone (iphone5 with ios7) was keeping wifi on when lock screen. At home the opposite. So the conclusion was, logically, that I had a problem with my router (Dlink 605L). After 2 days of googling, I fonud this post:
So I changed my router's name from "dlink" to other name (no matter which kynd of name) and the problem is solved now!!