Hmmm. I wonder if you have to have an app running on the wifi for it to stay on (EPSN radio, etc). I thought for sure I heard that it was supposed too though. Not a biggie, just the 1 thing I noticed.
When you put the iPhone to sleep, it turns the WiFi off to conserve the battery. When you awake it, it should turn back on and automatically reconnect with the network.
Push Notifications off, Push email off, no Apps running. Wake iPhone from sleep by pressing home button, then wait for screen to shut off (~7 seconds). Wi-Fi disconnects after ~20 seconds.
Jun 28 20:09:13 Severity:5 Associated with station xx:xx:xx:xx:xx:xx
Jun 28 20:09:13 Severity:5 Installed unicast CCMP key for supplicant xx:xx:xx:xx:xx:xx
Jun 28 20:09:34 Severity:5 Disassociated with station xx:xx:xx:xx:xx:xx
Same scenario, but with Push Notifications ON. After ~5 minutes I unlocked the phone, turned Push Notifications off, and relocked the phone.
Jun 28 20:13:24 Severity:5 Associated with station xx:xx:xx:xx:xx:xx
Jun 28 20:13:24 Severity:5 Installed unicast CCMP key for supplicant xx:xx:xx:xx:xx:xx
Jun 28 20:19:10 Severity:5 Clock synchronized to network time server time.apple.com (adjusted +0 seconds).
Jun 28 20:20:21 Severity:5 Disassociated with station xx:xx:xx:xx:xx:xx
It says right on their website that this is a feature for iPod Touch so that it can stay on for wi-fi VOIP calls and push notifications.
On the iPhone, this has been possible for quite some time on a per-app basis, not a global setting. I think I have at least two apps I've been using since 3.x.x that do this.
So if it's in sleep mode, and we get a beep indicating an email got pushed, that means it used cellular service, and is going against the data plan? For those of us that are new and are stuck with either 200 MB or 2 GB, that's something to keep in mind.
This is kind of a big issue as I see it. I just installed WiFi today (yeah i know...way behind the times right?) and I was hoping WiFi would just stay on... unfortunately I have to put in my password every time it goes on standby now.
I'm using Mobile Air Mouse and it doesn't keep WiFi on.