One question for iOS 7.1 beta users.

It's supposed to disconnect from WiFi when the phone is locked and then reconnect when you unlock. This has been the case for awhile now, even before iOS 7.

 

If you're not using it, what's the big deal? Of course if it's downloading an app or something while locked, WiFi will be on.

 

Battery drain.

It's done this since at least iOS4. It is not new for iOS7. Probably since the original iPhone OS 1.

 

Except WiFi consumes much less power than 3G/LTE. Would be better if the phone stayed on WiFi and just turned off cellular data.

 

It does it on my 4S running ios 6.1.3 as well. As far as i know, its always disconnected from wifi when locked unless there's an active download or something. As far as why, idk. I would think as long as theres no active dowload, battery drain would be no issue on 3G or wifi...

 

Usure if serious or troll...

You realize you would not receive sms, calls, or push... There defining functions of a mobile phone.

 

Calls and SMS do not use cellular data.

 

So you're saying you will still receive calls and texts if Airplane Mode is on?

 

Lol cellular data doesn't have anything to do with calling or texting. And push would still go through WiFi.

So no I'm not a troll. Just educated, I guess.

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Research more.

 

Nobody said that ...

But again, you will receive SMS even if cellular data is OFF.

http://support.apple.com/kb/HT4146?viewlocale=en_US&locale=en_US

 

Turning off cellular data != airplane mode. I'm surprised just how little you guys know about the phones you use. It's one thing to not know and therefore question and another entirely to call me a troll and poke fun at me for discussing something you know clearly very little about.

 

One question for iOS 7.1 beta users.

You mean the function to stop iOS from using IP traffic, so you can prevent going over data limits... But leaves the cellular radio and amplifiers on active and linked? Why would that conserve battery?

 

Because with data disabled the phone doesn't have to maintain an IP address by talking to the switches/servers every few seconds. In contrast, with no data connection (IE an old flip phone or with the setting off) normal calls and texts are pushed to the phone as they occur without the need for constant back and forth pinging, and the connection is otherwise nearly completely idle. It's not a HUGE difference compared to airplane mode killing the entire thing, but there is a difference.

 

It was a little ambiguous...

 

No it would turn off the LTE/3G radio. That's what's called the data connection and cellular data gets it's own hardware entirely. Turning off cellular data would power down this hardware, which is by far the most power hungry among all data peripherals, and instead use WiFi hardware which don't use nearly as much power.

It wouldn't just "stop IP traffic," it'd stop the entire data portion of the radio/antenna. Huge power savings.

 

No, no it doesnt. The hardware components are the same. The mdm9615 processes all voice/hspa/edge/lte, and so does the wtr1605 rf transceiver as well as any associated Skyworks amplifiers. All pass through the same hardware. These parts will be in operation to some degree for the phone to act like a phone.

With wifi, it can shutdown the broadcom chipset entirely and separately.

 

If you cease using LTE/3G/cellular data in general, the chip uses up far less power. I'm not familiar with the internal workings of the chip but I'd be willing to bet it internally shuts down segments of itself when cellular data is turned off. Either way the power savings are massive and it's kind of common knowledge that using WiFi (and turning off cell data during WiFi use) offers a huge savings in power consumption. I'm not really sure how somebody can argue this.

 

It's actually not necessarily/always true that push would go through Wi-Fi, and that might play some role in all of this as well: http://support.apple.com/kb/TS4264

 

That's only if you have proxies and such, or a router that has blocked internet access in some way.

 

http://www.apple.com/uk/batteries/iphone.html

"Enable Wi-Fi: Having Wi-Fi enabled helps consume less power when doing activities that access data. Go to Settings > Wi-Fi and log in to a Wi-Fi network."

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I don't think this conflicts with the idea that, when idle, shutting off wifi will improve battery life. The above advice just says that wifi consumes less than 3G when accessing data. What I get from this is, e.g. if you download lots of data over 5 minutes, it's more efficient to do this over wifi. But if you are downloading no data over 5 mins, shutting down wifi will use less battery during that 5 mins than if you left it on.

Push notifications you might receive during idle are probably so small that there are more gains in turning off wifi than leaving it on (assuming a long enough idle period and not many notifications).

Who knows what sort of intelligent stuff is built into the OS management of radios- it's quite hard to tell when the screen is off! But here are some ideas just to stretch your imagination.

Perhaps if you receive a lot of push notifications when idle, Apple learns from this and keeps wifi active during times when it thinks lots of notifications might come in.

Perhaps when an email header is pushed to the phone over 3G, it connects to wifi to download the body.

Perhaps during idle when apps are refreshing in the background (new iOS 7 feature), it connects to wifi to download/upload any data.

But if your phone is not actively doing anything, and if the only data activity might be the odd notification (which are only a few kb), it probably pays off to turn off wifi. They are also so small that they probably won't even upset people with little data on their contract.

 

The short answer is if not using it then turn it off. If not using bluetooth... Turn it off. It out and about turn WIFI off.

If on WIFI I leave cellular on as it should put the cellular data in a standby state but I keep it ready incase the WIFI drops or Cellular would be faster.

The 2 things about this I hate is the insistence to have WIFI on to download if over a certain file size even though some people ( a lot ) will have not only ample data packages but the cellular data is faster than their WIFI network.

The other is people who leave WIFI on all the time when not on a network thinking it's not draining the battery. In theory by my understanding anyway is it's like Bluetooth... It is using power because by being on it is trying to constantly establish a connection.

So just be smart, if your not using it or not likely to need it then don't have it on.

 

Unless you perhaps have it set to ask to join networks it shouldn't be looking for them all the time if you leave it on.