Wifi drops when phone is locked after 10.3.3 update

This is not anecdotal. I have been testing it with every iOS release. Nothing has changed. Here is how to actually test it:

• On your phone go to Settings/Wi-Fi and tap on the i next to the network name
• Write down the IP address
• On your computer open a Terminal window (Mac) or CMD window (Windows)
• Enter "ping <the IP address you wrote down>" (Mac) or "ping /t <the IP address you wrote down>" (Windows)
• Note the phone responding to the ping command
• Press the SLEEP button
• Watch as the responses stop after about 30 seconds
• To stop the pings enter <CTRL>+C.

Every time a major version is released I do this again. The response has never changed in 10 years.

Repeat the test with the phone plugged in; it won't go to sleep. It may wake up for a few seconds if the phone receives a notification such as a Push email alert, which is an external stimulus, but apps that originate communications will not wake it and will use cellular data.

This issue plagued me for years. No help from Apple or anyone

I have solved this on my iPhone 6S and my iPad Pro

Both run iOS 11.1

This has worked for my since IOS 8

The issue is on your WiFi router and or access point.

Under your WiFi advanced / professional settings change:

DTIM interval to 2 or 3

Beacon Interval to 50-100 or less

Lowering these numbers will cause devices to stay connected longer when asleep so it may cause more battery drain.

Lowering beacon make the AP broadcast “I’m here” more often.

Lowering DTIM causes devices on sleep (locked) more to wake up and reconnect more often.

You may have to play with those numbers a bit. Lowering them fixed my WiFi / lock disconnect issue. But it does increase

Since I set my ASUS WiFi AP / router to DTIM 2, Beacon 50, my devices rarely drop WiFi when locked.

Similar symptoms fixed by simplifying my SSID (after a 2 week diagnostics path).

Symptoms: >10.3.3 after approximately 1 minute of phone-sleep upon reactivation the topbar WiFi symbol would dropout in preference of 3G/4G. It would re-establish a second or two later. Prior to (approx) 10.3.3 the WiFi symbols wouldn't do this. During sleep no incoming WiFi Calling calls could establish (which previously they did fine) - I got VMs. I can see, normally, ping responses are not continuous and intermittent when in sleep. During the fault condition - IIRC - ping responses just stopped a little after sleep and did not resume. Post fault-fix - I see them stop/start. I suspect the issue that's causing trouble wasn't the WiFi powersave feature itself, but perhaps the resume from that mode - but I have no logs/evidence for this supposition...needs to be something linking to the long SSID in my case.

I have two home WiFi networks - one on which the phone exhibited the issue - one on which it did not. After trying a lot of things (network resets; factory resets of one of the affected three iPhones; WiFi settings including the above; replacing the faulty AP with an Apple Airport Extreme off eBay), I transferred the SSID from the faulty to working router. That transferred the problem. It was the SSID - the only thing that transferred other than the PW.

My SSIDs were 31 and 32 characters respectively between the working (802.11n Thompson from ISP)/non-working AP (Asus RT-AC68U running latest from Merlin).

Obvious in retrospect - but I then reverted and changed the problematic 32-char SSID AP to an SSID of 'Bob' - same long password - and the problem has now gone. A simpler nine character SSID is also good (alphanumeric, inc caps). Solid the last few hours since doing.

Try simplifying your SSID if affected? HTHs.

Edit with some more diagnostics for Apple Engineering:

----

Similar symptoms fixed by simplifying my SSID (after a 2 week diagnostics path).

Symptoms: >10.3.3 after approximately 1 minute of phone-sleep upon reactivation the topbar WiFi symbol would dropout in preference of 3G/4G. It would re-establish a second or two later. Prior to (approx) 10.3.3 the WiFi symbols wouldn't do this. During sleep no incoming WiFi Calling calls could establish (which previously they did fine) - I got VMs.

I have two home WiFi networks - one on which the phone exhibited the issue - one on which it did not. After trying a lot of things (network resets; factory resets of one of the affected three iPhones; WiFi settings including the above; replacing the faulty AP with an Apple Airport Extreme off eBay), I transferred the SSID from the faulty to working router. That transferred the problem. It was the SSID - the only thing that transferred other than the PW.

My SSIDs were 31 and 32 characters respectively between the working (802.11n Thompson from ISP)/non-working AP (Asus RT-AC68U running latest from Merlin).

Obvious in retrospect - but I then reverted and changed the problematic 32-char SSID AP to an SSID of 'Bob' - same long password - and the problem has now gone. A simpler nine character SSID is also good (alphanumeric, inc caps). Solid the last few hours since doing.

Try simplifying your SSID if affected?

I can see, normally, ping responses are not continuous and intermittent when in sleep. During the fault condition - ping responses just stopped a little after sleep and did not resume (confirmed in a non-clinical way by a quick reversion). Post fault-fix - I see them stop/start - but the important thing is they restart of their own volition - presumably as a process needs WiFi up for a bit. I suspect the issue that's causing trouble wasn't the WiFi powersave feature itself, but perhaps the intermittent resume from that mode - although I have no logs/evidence for this supposition...perhaps someone has only allowed 32 chars for the SSID in the saveset?

Apple Engineering - if you can hear me are listening - please check the sleep-resume bit of your WiFi codebase for SSID-length limitations.

HTHs.

Well after months of having this issue even after upgrading to IOS 11.1 I have finally sorted it. Some of the message replies on this thread have been downright rude, and as for people saying this is the way it is supposed to work you are so wrong. Since the first iPhone my wifi never disconnected at all when I left the phone for more than 2 minutes unless I disabled it right up until my iPhone 7 this was the case. Maybe its a fluke who knows but what I know is that my phone encountered this issue and It was a royal pain in the ***, because some apps needed to be connected to my network and they would say Out of home connection and try reconnecting until it found the network again. Anyhow my solution try and see if it works for you. Settings----Wi-Fi----- click your Network and deselect the Auto-Login. Never had a drop of wifi since.

Regards

Scoop

Asfuq wrote:

Thanks for the respond. But actually i need a solution.

There is no "solution". It is working exactly as it was designed to work.

If you want to maintain a constant WiFi connection when the phone is in standby, it must be connected to an external power source.

Notwithstanding Lawrence Finch's inevitable rebuttal, the solution Silverteem posted worked for me. Thanks, Silverteem! The facts on the ground where I'm standing are:

My WiFi would disconnect when my phone went idle. I know this, because if I were in the middle of either uploading pics to Dropbox or downloading updates from the App Store (both of which I've set to work ONLY on WiFi, not data/network) and my phone went idle, when I would "wake" the phone from idle, the 4G icon would appear in the upper-left of the screen for 3-6 seconds before the WiFi icon would appear, and during those 3-6 seconds I would get a "no connection" message from either the Dropbox app or from the App Store, depending on which one was active on the screen when it went idle. The ONLY reason for getting the "no connection" message from either of the apps whose settings ONLY allow it to work when connected to WiFi is, of course, if at the moment of "waking" my phone, it was NOT connected to WiFi, it WAS connected to data. So obviously in those 3-6 seconds upon waking my phone, I wasn't connected to WiFi. I was connected to my data network. (Whether that is or isn't how Apple intended iOS and the iPhone to work is irrelevant to this discussion. So don't bother saying "Yes, WiFi disconnects, because that's what it's supposed to do." I don't GAS. The issue is whether that behavior can be altered. The answer is "Yes.")

So I did what Silverteem recommended: With my phone NOT connected to an outside power source, I turned off/disabled "auto-login" in my WiFi network just now. Luckily I have 10 apps that need to be updated. I went to the App Store and told it to Update All apps. Then I set the phone down and didn't touch it for more than a minute. With it NOT being connected to an outside power source. Just battery power (45%).

When I "woke" the phone, the App Store was STILL updating the apps, the WiFi icon appeared instantly in the upper-left corner of the screen, and the App Store did NOT tell me that I need to connect to WiFi to continue updating my apps. (I also let it sit for more than 5 minutes while I drafted this reply, and when I woke the phone it was still connected to WiFi and the App Store was still actively downloading the updates, no "no connection" message to be found.)

Those are the facts on the ground. I don't give a rat's arse about the (alleged) history of iPhones or of iOS or of Apple.

The FACT is, I just did what Silverteem recommended, and my WiFi no longer disconnects when my phone goes idle while it's doing something (e.g. uploading to Dropbox, downloading App Store updates). You Apple fanboys and aficionados and techies can dispute this 'til the cows come home. The facts on the ground prove you wrong and prove Silverteem right, at least with regard to MY phone. QED

Here's what does demonstrate that WiFi was "on" when my iPhone locked:

My App Store is set to only update/download when connected to WiFi. It does not work unless WiFi is connected. And if I try to use it when I'm not connected to WiFi, I get a message telling me "Turn on cellular data or use Wi-Fi to access the App Store."

Last night I needed to update 10 apps. I disabled Auto-Login as Silverteem recommended, and then I began the updating process, while connected to my home WiFi but not connected to an outside power source.

The App Store updating process continued as the phone went from awake to asleep and back to awake. It would not have continued updating had the WiFi disconnected when it went to sleep (locked). When I woke it back up, it no longer showed the 4G icon for 3-6 seconds (as it has been doing for a few months now). It showed the WiFi icon immediately. That is a change from past behavior solely due to disabling Auto-Login, and it's silly to argue that "that only means that the WiFi icon is working." What, the WiFi icon didn't work for 3-6 seconds upon waking the phone in the past, but now that I've disabled Auto-Login the WiFi icon works immediately upon waking? Baloney.

Furthermore, the App Store did not briefly tell me that there was "no connection" upon my waking the phone, as it had in the past under identical circumstances other than disabling Auto-Login. When my phone would go to sleep in the past, App Store updating would stop (as would Dropbox pic uploads; I also have Dropbox set to work only when connected to WiFi).

Last night I was still connected (and the App Store was still updating) immediately upon waking my phone. No 3-6 second delay to reconnect. That was not happening in the past. That is happening now that I've disabled Auto-Login. The only variable in my test was Auto-Login. Now that it's disabled, the App Store continues to update even when the phone goes to sleep, which it would not do prior to disabling Auto-Login.

My WiFi was connected when my phone went to sleep and my WiFi was still connected when I woke my phone a few minutes later, which I know for a fact because the App Store updating was still happening, which hadn't been the case in the past, before I disabled Auto-Login.

I don't know whether Silverteem and I have the only 2 phones out of the billion that do this. I do know that Silverteem's advice solved the problem for me.

Rayclod wrote:

1. Can anyone suggest me does iPhone X has the same issue

It's already been made clear here numerous times. ALL iPhones do this. It is by design. It is not an "issue" it's the way it's supposed to work.

2. Can anyone help me direct email address of iPhone support central.

All methods of contacting them can be found here: Contact Support

3. I have visited the local support here but they cannot help me on this.

That's because it is NOT broken.

I recommend following Silverteem's suggestion. I did, and it solved the problem for me. Maybe the "problem" is the way iOS and the iPhone are supposed to work, but just because something does what it's supposed to do doesn't mean it's not a problem for many users. Silverteem's suggestion "fixed" or solved the problem for me, and I didn't have to take the time and effort to jump through all the hoops of factory resetting, backing up, restoring, etc.

Just disable "Auto-Login" and see if that does the trick. It did for me. I did it five (5) days ago, and the "problem" has disappeared completely. It has not come back a single time since then. (Just tested it again this very moment, and the WiFi icon appeared immediately upon waking my phone, no delay and no 4G icon for the 3-6 seconds that it used to appear.)

OferL wrote:

Apple senior support advisor did run diagnostics on my phone last night, declared it fully OK and actually claimed wifi dropping is a feature not a bug.

So wifi drops intentionally to save power even though battery is full and device is on charger.

As has been mentioned numerous times already in this thread. People just refuse to believe it. Wifi has always cut out when the device is on battery and the screen locked.

And now we’ll get numerous further posts saying this is not so. But in fact it has always been so.

iCloud backups will occur automatically only when the device is plugged in, since when plugged in to an external power source, wifi stays on when the screen locks.

I had this problem too.

Device: iPhone SE iOS 10.3.1

The only solution that worked for me:

(found in Tanaza web site https://www.tanaza.com/blog/wifi-disconnects-sleep-mode-iphone-6s-ios-devices-pr oblem-solved/)

1. Turn wifi on (doesn’t matter if you connect to a wifi network now or later, but the wifi toggle must be on). If your ios device supports mobile data, turn it off for now.
2. Turn off the device (by keeping the sleep button pressed and then swiping)
3. Wait 30s
4. Turn it on
5. After the home screen loads, reset it (hold the home and sleep buttons down and keep holding until you see the apple logo)
6. That’s it.

I don't know why, but it worked.

Every one of the over 1 billion iPhones sold has always dropped WiFi when the phone goes to sleep, unless it is connected to power. It will reconnect for 30 seconds if the phone receives a notification or push email alert. However, it will NOT reconnect if an app on the phone attempts to use data; the app will use cellular data, or, if cellular data is not available, it will wait until the phone wakes up. It does this on 10.3.3 certainly, but it also did it with every version of iOS since 1.0. Your experience was not different before 10.3.3; you are misremembering, or didn't notice.

From the publicly available Apple iOS developers library - https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPho neOSProgrammingGuide/PerformanceTips/Per…

Using Wi-Fi

If your app accesses the network using the Wi-Fi radios, you must notify the system of that fact by including the

UIRequiresPersistentWiFi

key in the app’s

Info.plist

file. The inclusion of this key lets the system know that it should display the network selection dialog if it detects any active Wi-Fi hot spots. It also lets the system know that it should not attempt to shut down the Wi-Fi hardware while your app is running.

To prevent the Wi-Fi hardware from using too much power, iOS has a built-in timer that turns off the hardware completely after 30 minutes if no running app has requested its use through the

UIRequiresPersistentWiFi

key. If the user launches an app that includes the key, iOS effectively disables the timer for the duration of the app’s life cycle. As soon as that app quits or is suspended, however, the system reenables the timer.

Note: Note that even when

UIRequiresPersistentWiFi

has a value of

true

, it has no effect when the device is idle (that is, screen-locked). The app is considered inactive, and although it may function on some levels, it has no Wi-Fi connection.

iOS, on all iOS devices, has always behaved this way. I know that once again, the nay-sayers will simply post back saying the Apple "fan boys" are wrong, and all I can say keep on looking for your fabled fix to what has never been a bug but is the deliberate way iOS has been coded to function.