Denver Dev Blog » Apple

iPhone 4: Excessive nightly 3G Data Usage while on WiFi

Matthew McCullough — Wed, 21 Jul 2010 17:40:31 +0000

With my new iPhone 4, I thought “I’ll just switch to a 200MB data plan” since I mostly use WiFi and have rarely had a month of greater than 150MB data usage.

What a mistake. With no apps running in the background, Push turned off and Notifications turned off, according to the myWireless AT&T app, my phone is using between 5 and 50 MB of data per night. The usage occurs between 11pm and 3am MT. Upon waking the phone up, it shows it is connected to WiFi, but I get a momentary flicker of the 3G icon. That’s what makes me suspicious it is using 3G instead of WiFi when it goes to sleep. That behavior is contrary to documentation.

Articles and Links

There’s no shortage of material to point at extolling variations of this problem. Some are old — as far back as 2008 — but the post frequency and number of new threads has increased, centered around the iPhone 4 launch and anyone transitioning to a 200MB data plan.

An Apple forum 3+ page post on iPhone 4 using Cellular Data when on standby and connected to wifi.

A MacRumors thread that states “it’s speculated that it’s being sent via 3G because the phone typically is sleeping when this occurs, and iPhone (at least until iOS 4.0) never connects via WiFi while asleep – only via 3G”

The 10 page Apple discussion entitled “Unknown data usage early morning”.

An AT&T forum thread entitled “iphone 2am unauthorized data usage”

Another AT&T thread from 2009 stating similar complaints on iPhone OS 3.0

A claim that it is just a usage tally (which still doesn’t explain the days I never leave the office WiFi).

“iPod touch can stay connected to Wi-Fi when asleep so you can receive incoming VoIP calls and notifications from compatible third-party apps.” So, WiFi should stay connected.

“There’s no word on whether this applies to the iPhone as well (since cellular data is typically persistent anyway), but it would be a nice feature to have in all iOS devices — including iPad, especially when roaming with data turned off, or even just to prevent the delays that usually accompany reconnecting to Wi-Fi based remote control apps.”

Older, 2008 post claiming “Wi-Fi is usually turned off a little while after in standby.”

Conclusion

The only logical explanation is that everyone is just holding it the wrong way, thereby causing it to use more data on 3G than it should.

iPad, iPhone Certified Developer Program – A Wild Idea

Matthew McCullough — Fri, 14 May 2010 20:10:51 +0000

As much as we (the Software Engineering industry) detest testing and certification, Ben Ellingson and I were wondering if it would be useful to have an Apple iPhone skills-certified developer program. The idea would be that a developer would pass a certain skills test and then be permitted to directly publish bug-fix updates to the store without the usual review waiting period. I realize this is controversial and further cements Apple’s importance in a software release process where many think they should not be involved.

iPhone 2G Network Switching from 850Mhz to 1900Mhz?

Matthew McCullough — Mon, 05 Jan 2009 01:18:00 +0000

Here’s an interesting, though only lightly cross verified fact. AT&T might be moving the 2G network over to the 1900Mhz band (your phones are practically tri-band, nowadays) and using 850Mhz for more of the 3G network. 850Mhz penetrates barriers more easily, thereby yielding, in most cases, a better signal reach and strength. I have noticed and commented to co-workers (prior to this article) an lessened ability to get 2G signal in many of my normal locations around Denver. So to me, this is a consumer scientific same-data-point test, and I’m seeing reduced throughput and signal strength (in some cases, 0 bars now at places I used to be able to get 2 or 3). Comments from anyone with a 1st Gen iPhone?

MacBook Pro (late 2008) “Hot Laptop In Bag” Troubles

Matthew McCullough — Thu, 11 Dec 2008 04:27:00 +0000

As an owner of two “MacBook Pro (late 2008)” units (gotta love the Apple official model title), I’ve experienced an overheating issue quite frequently. It’s becoming known as “hot laptop in bag, syndrome, v2″. Here’s a quick tour of the problem with a bunch of the news articles published in just the last few days.

There’s a quick description of the problem by Gizmodo then, the actual thread on the Apple site, followed by a suggestion to use SmartSleep to turn on Hibernate mode only, or reset your SMC, or reset your PRAM, or actually get a firmware fix. Take your pick.

And if you don’t find that enough, go ahead and check out the electron microscope pictures and spectrograph of the bump composition that says NVidia is not being transparent about the failing video chip problem.

Does this just make you want to run out and buy one of these new units?

Lest you think I’m switching back to PCs, these Macs are still way better than my last Dell D600 that required 4 complete overhauls for failed components in a 90 day period.