4 Replies Latest reply: Aug 4, 2007 9:25 PM by Matt Kulka
Peter000 Level 1 Level 1 (35 points)
Does wifi shut itself off when the iPhone is in sleep mode? I've noticed when I wake it up, the "EDGE" symbol up top is visible for a few seconds, then it flashes the wifi indicator (when I'm close to a wifi source, of course).

Hopefully this is not the case, because it would seem like background tasks like mail checking would be more efficient using wifi. Or does mail check over EDGE automatically anyway, even if wifi is connected?
  • 1. Re: Wifi disconnects when sleeping?
    Chas Hulme Level 4 Level 4 (1,130 points)
    I believe that WiFi does also snooze during iPhone sleep to save on battery life. The GSM radio of course needs to remain active to accept calls from the cellular net... Now, I had assumed that it will use WiFi as needed, during sleep. There's no reason I can think of why it wouldn't, and it would make sense. But, if you want a definitive answer on this, you might test it with the SIM removed. Or maybe someone else here has already investigated this.
  • 2. Re: Wifi disconnects when sleeping?
    bnbzone Level 2 Level 2 (405 points)
    if the sim is removed it wont work... but during sleep the wifi turns off and back on when needed or when you come out of sleep
  • 3. Re: Wifi disconnects when sleeping?
    Chas Hulme Level 4 Level 4 (1,130 points)
    "if the sim is removed it wont work..."

    Could you clarify what won't work with the SIM removed? All phone functions? ...I am curious because of the side discussion about airplane use where the carrier supports WiFi, and don't care to do testing on my iPhone... Someone suggested removing the SIM, to which I said that wouldn't meet federal regs. But I would welcome info from someone who has actually tested this.

    BTW, sorry for the unintentional and partial thread hijack... Another thread can be started depending on the response.

    Message was edited by: Chas Hulme
  • 4. Re: Wifi disconnects when sleeping?
    Matt Kulka Level 1 Level 1 (85 points)
    Yes, Wifi does sleep shortly after the device when on battery power. I've noticed that it doesn't (or at least as much) when plugged-in. The reason for this is, of course, power saving as the iPhone doesn't do anything on it's own (aside from checking your email at specified intervals and I believe checking for/fetching voicemails). It'd likely wake up the Wifi when those functions are needed.

    Despite what I've read others' hypothesize, it does not automatically update Safari, Weather, Stocks or Maps while it's sleeping.