Does Wi-Fi turn off when locked

Guybrush-Threepwood wrote:
In 4.0 and 4.0.1 the wifi was persistent on the iphone.

In 4.0.2 they changed it to disconnect after being in sleep for 10 seconds.

However, if your data connection is turned off in the settings the wifi will remain on when in sleep.

This was confirmed by a member of Applecare.

What I notice on my iPhone 4 is that wifi is off when the screen is locked. If I try to facetime to my phone from my wife's ipod touch, then my iPhone doesn't ring at all unless I wake it and the screen is on. I think that this is a problem. If I try the other way and facetime from the phone to the touch, that works fine. When the touch screen is off the touch still "rings".

I had a battery draining problem after i had add another e-mail account so i'd put fetching off, but it deedn't seem to put off wifi at first on lock. only after i'd seen there's an advanced option that goes with fetch new data the problem was solved

if you'd like to save battery, and auto turn wifi off when locked:

(BTW) I'm running ios 4.2.1 on ipod touch 2g, couldn't tell about whether this works on iphone

Settings --> Mail, Contacts, Calendars --> Fetch New Data

turn Push Off --> set Fetch to manually (applications will go through fetching data only when opened or manually updated, NOT on a timely basis)

scroll down and press Advanced

(make sure all accounts are set to Manual, if one is on Fetch, Wifi will be ON all the time and drain your battery anyway)

Brilliant! Thanks erijkgabriel. Clicking through to the Advanced screen reveals the culprit. No matter that you have Push "Off" and that you have Fetch "Ticked" as Manual, while any mail account is set to "Fetch" status it will force the phone to attempt to keep a connection active even while in sleep. (That is, if Data is Off, and have wifi switched to On.) Seems like an OS error to me. Setting Fetch to Manual should disable any associated tasks within the phone.

I have an iPhone 4S with iOS 5.0.1, and need to keep 3G off to save battery, so I keep my wifi on.

I've been doing a simple ping and realized that is not persistent, but it also wont stay off al the time.

The behavior is very random:

With the phone active Wifi is active (obvious)

When locked it maintains the wifi active for 20 secs

Wifi goes off for 20 secs

Wifi goes on for 20 secs

Wifi goes off for 20 secs

Wifi goes on for 20 secs

and keeps repeating that behavior...

Sometimes the cicles are longer or shorter than 20 secs, I've seen 5 secs cicles and 1 minute cicles, I really would like to know what services are waking up the wifi, or what this cicles depend on.

Hope this helps.

luis144 wrote:

I have an iPhone 4S with iOS 5.0.1, and need to keep 3G off to save battery, so I keep my wifi on.

I've been doing a simple ping and realized that is not persistent, but it also wont stay off al the time.

The behavior is very random:

With the phone active Wifi is active (obvious)

When locked it maintains the wifi active for 20 secs

Wifi goes off for 20 secs

Wifi goes on for 20 secs

Wifi goes off for 20 secs

Wifi goes on for 20 secs

and keeps repeating that behavior...

Sometimes the cicles are longer or shorter than 20 secs, I've seen 5 secs cicles and 1 minute cicles, I really would like to know what services are waking up the wifi, or what this cicles depend on.

Hope this helps.

That does not match my testing. I can monitor my wireless router activity on my laptop, and the IP used by my iPhone 4S goes inactive after 10-20 seconds after putting it in locked mode, and doesn't come back on until the phone is unlocked. This is a problem because any activity that needs to take place will then go to 3G, running up the data usage. It appears that the phone contacts someone twice a day and transmits something, on the order of up to 3MB each time. Assuming maximum transmissions twice a day for 31 days, I would be using up to 186 meg/month! Now I have an unlimited data plan, but my wife, and her sister are on my bill, and they have only 200MB data plans. I am quite curious what is being sent, and to whom, since I have all the 'system services' things turned OFF, and also diagnostics and data off. I am sure ATT loves this!

Running IOS 5.01.

erijkgabriel wrote:

I had a battery draining problem after i had add another e-mail account so i'd put fetching off, but it deedn't seem to put off wifi at first on lock. only after i'd seen there's an advanced option that goes with fetch new data the problem was solved

if you'd like to save battery, and auto turn wifi off when locked:

(BTW) I'm running ios 4.2.1 on ipod touch 2g, couldn't tell about whether this works on iphone

Settings --> Mail, Contacts, Calendars --> Fetch New Data

turn Push Off --> set Fetch to manually (applications will go through fetching data only when opened or manually updated, NOT on a timely basis)

scroll down and press Advanced

(make sure all accounts are set to Manual, if one is on Fetch, Wifi will be ON all the time and drain your battery anyway)

I had calendars set to fetch, but wi-fi was going off anyway. iPhone 4S with IOS 5.01. Turned fetch off anyway.

Ghostrider501 wrote:

wifi stays connected on the iPhone 4 when in sleep mode.

On my iphone4. Wifi switched off, 10hours later, mostly sleep mode, maybe 2or3 text sent, battery was down from 100% to 90%


Wifi switched on, 2hours later, in sleep mode it went from 90% to 79%

So for me, it stay on, which I find is very wrong and a major battery drain.

How are you determining that wi-fi is actually active?

this is true for all apple products all iphones ipods and ipads but for iphones if you are somewhere where you know you have a good wi-fi connection you can go into your settings and turn off cellular data and it will stay connected to wi-fi even when it goes into sleep mode but remember when you leave the wi-fi spot you will have to go back into settings and turn cellular data back on because it wont do it automatically