Lol. I know. It won't.
I gave up so long ago, but still get the email alerts. I keep up on the posts, but haven't tried anything in quite some time. No one seems to have an idea that works more than briefly. Of course Apple knows about it. I take advantage of it when it works, curse it and use the cord when it doesn't.
Good Luck All!
I think the issue may be coming from an App installed on a iphone or Mac computer which is inhibiting the wifi. The software may be common to many users...or it may be a similar string of code within the program. If there was a way to create a user app database a trend may be identified.
My iphone or Mac wifi sometimes needs manual reset post a phone call. But most of the time it's good.
Also, please keep in mind that within iTunes is a 'click box' which enables wifi sync to iTunes. I found this troublesome at first as I could establish a wifi connection and then when I opened iTunes it would drop the wifi connection. I poked around in itunes and clicked the enable wifi sync box and it works as designed.
I was wondering if your wifi sync works after the computer has gone to sleep. In other words does the request for wifi sync wake the computer up?
In my case I am able to sync while the computer is awake. After the computer has gone to sleep it hardly ever works. If I press the sync now button I can tell that the harddrive wakes up but the sync does not happen. Also, after waking up the computer in that state the sync will usually not happen even with the computer awake. Restarting the router or computer or itunes or phone or sometimes combination of the above will restore the sync with the computer awake.
Wanted to see if anyone could comment on this. Apple calims it is my network and that it works in their pure Apple environment.
Wow, been a busy thread lately... Just to add my two cents to different posts...
I have an iOS 5 and iOS 6 device, and they both seem equally plagued by this issues, so I personally don't see this as an iOS 6 issue. I really thought many of us were agreeing it seemed to be an Exposé issue. With so many updates to iOS and iTunes, it's probably hard to narrow down exactly what the issue is.
I can never sync when my Mac is asleep, which doesn't surprise me.
I feel like the issue is much better lately. But whenever the problem arises, it seems simple enought to fix -- just disconnect your iTunes Mac (or PC?) from your network and connect it again (either turn off the wifi and then turn it back on, if that's how you connect, or unplug your ethernet connection and plug it back in). I know that easy fix works for many of us here.
This one issue certainly isn't going to make me change to a different phone or computer. Though I agree, the HTC One is a nice-looking device!
For whatever it's worth, I have an AppleTV device plugged in, which I have not used for the past year. So I unplugged it last night to power it off. And this morning my iPhone4 and iPad2 started to work again (I didn't restart the iTunes, or the devices, and WiFi sync wasn't working last night).
Not sure if the AppleTV had anything to do with this? I did notice that AppleTV showed up in Bounjour (as a air play device??), and WiFi sync is also based on Bounjour.
Mea culpa: I have an Apple TV 3. 3 months ago, I had an Apple TV 1. ATV 2/3 are streaming devices, so my ATV3 does not show up in iTunes as did my ATV 1 which did and it synchronized its internal drive to selected titles.
All that said, WiFi sync performance seems to be the same with ATV3 as with ATV1.
I use Connectify to share my Internet via wifi, from my cable modem, thru Ethernet to my laptop. No actual router. It all seemed to work fine syncing my 3GS to my laptop running Windows 7, 64 bit. Then around the time of iOS6 or the iTunes released around that time, my 3GS stopped being syncable reliably. My girlfriends 3GS and iPad 2 on her WinXP machine stopped also. She now has an iphone 5. No better. I got an ipad mini a lil over a month ago. It seems more reliable than any of the others, and often shows up to be synced when my phone doesn't. But sometimes the opposite occurs. Sometimes they both work, when not plugged into power, sometimes both when plugged in, sometimes one or the other, sometimes neither. I would say the mini works less than half the time, but still more an twice as often as the other devices. But this seems across the board, regardless of OS, Mac, Win, version, XP, 7, 10, iOS# and device seem to make no difference. Type of wifi, band, frequency, router or not, static IP or not, it seems to affect all. Everyone has a good day and thinks things are finally fixed, I am curious if anyone has had a single week of reliability since it al started.
I am making more progress now. WiFi sync has been working perfectly for more than 36 hours -- for the first time in more than 6 months!
 Unplug all Apple TV from network
 On my Mac, open Terminal and run "ping apple.com" continuously.
 Make sure iTunes is the active app on my Mac, and lock the screen by choosing "Login Window"
 Set all iOS devices to use static IP address
I suspect that my Mac (or my router) has trouble keeping its network connection up. By running the "ping", which sends one network packet per second, probably keeps the network up.
I also noticed that if iTunes is not the active app, it seems more "sleepy".
Now as soon as I plug my iPhone/iPad (both are 6.1.2) into charger, they start syncing immediately. Before, they would show the "looking for XXX's Mac" message for a few seconds, then start syncing (on a good day) or fail (usually).
I am running a Mac Mini basically as a file server and web server. It never sleeps. I rarely use it myself. But I allow my daughter to use it for 30 minutes per day. So she has a separate login session. So we have two login sessions on the Mac at the same time.
I also make sure that my daughter's account cannot launch iTunes or iTunesHelper (by making myself the owner of these 2 executables, and chmod og-rwx). In the past, whenever I plug in the iPhone onto the Mac, her account would start running a second copy of iTunes, and that probably confuses the whole wifi sync protocol).
Not sure if this will keep on going. I have my fingers crossed and will report any updates.
Tomei Ningen: I am impressed by your ingenuity! I am also chagrined that you had to go to such lengths to try to make WiFi sync work (Apple, please note.).
I would classify your arrangement as an extensive work around and is not something I'd be willing to do, except in a test environment that I could 'crash and burn' without any impact on my life.