TiPb Answers: Why over-the-air iOS updates matter

TiPb Answers: Why over-the-air iOS updates matter

With rumors that Apple might be exploring over-the-air (OTA) updates for iPhone, iPad, and iPod touch in iOS 5, we're going to take the opportunity to go over how OTA updates work, what the advantages and disadvantages are (there's always a mix of both), and why they should matter to you.

For the answer, follow on after the break.

Currently if you want to update iOS, you need to plug your iPhone, iPod touch, or iPad into iTunes via the USB dock cable, hit the Update button, and watch as your iOS device is backed up, a roughly 500MB firmware file downloads to your Mac or Windows PC, the firmware completely replaces the contents of your iOS device, and then your data is restored from the previous backup and your content is synced back from your iTunes library. It's a great, tested and true process that results in backups for users, fresh installs for Apple (which are typically more reliable), and a device that is completely updated and restored to exactly its previous data state for the user.

The OTA advantage

If the current iTunes-based update process just works. So why OTA? What's wrong with the current process?

  1. It requires you to get to a PC with iTunes. And not just any PC, but the "one" PC that contains your iTunes library or you won't be able to re-sync your content (thanks Hollywood!). If that PC with iTunes isn't handy, you can't properly update.
  2. It requires full firmware replacements. That means even if Apple only needs to fix a single Safari exploit or location database bug, you need to download a roughly 500MB firmware and go through the same update process, detailed above, as if you were updating to a completely new OS, like going from iOS 3 to iOS 4.

OTA updates would mean you could update anytime, from anywhere, without having to tether to your iTunes PC. If you're at work -- or on vacation -- you don't need to wait until you're home.

It also means that Apple could, if they chose to, do smaller and more frequent patches when security issues arise or when critical bugs are found.

In fact, Apple's already doing them in 2 instances:

  1. Apple TV (2010). It runs iOS, but rather than plugging into iTunes, it handles iOS updates right on the device. However, it is always plugged into AC power, and it's always on Wi-Fi or Ethernet. (We'll address why that's important later.)
  2. Carrier Setting Files. Since iOS 4, Apple has been updating the files that determine, for example, tethering and mobile hotspot availability, group SMS functionality, and other carrier-specific settings.

Competitors like Google's Android and HP/Palm's webOS based phones have been doing OTA updates as well. But it's not without its problems.

The OTA disadvantage

Since other smartphones have been doing OTA, we can see some of the problems that have arisen:

  1. 3G/cellular data. Once you start allowing OTA updates, users might really expect them to be available everywhere, including when they're away from Wi-Fi and on 3G connections. If Doing them over 3G can mean longer download times, the possibility of hitting up against data caps (if you're on a 250MB plan, you couldn't even download the firmware once), and carriers refusing to allow large downloads (like they do now with the 20MB iTunes/App Store limits.) Apple's install base scares the network out of them. Likewise, If 3G updates are allowed, and if someone accidentally does a large update while roaming, their bill could be excessive. Conversely, if someone doesn't have 3G but gets stuck on EDGE, GPRS, or 1xRTT (see our networking glossary) they could be painful to the point of impossible.
  2. Delays/rollouts. When Google or HP roll out an Android or webOS update, not everyone seems to get it at once. Indeed, it took my Nexus One a couple weeks to pop up the OTA update for Gingerbread. iTunes delivers updates the instant Apple releases them. Why other platforms have used rollouts instead of just releasing their updates all at once, I'm not sure, but if the same factors (and/or carrier demands) force rolling updates for iOS, people who aren't used to waiting may not be happy about waiting.
  3. Restores/Re-syncs. As mentioned above, currently iTunes backs up and restores your iOS device while updating the full firmware. (Apple TV OTA updates don't do this because it's streaming-only and so doesn't have to worry about local content). Handling a roughly 500MB firmware update is one thing. Handling up to 64GB of content backup and restore is another. Of course, Apple might switch from full firmware backups to a patching system, or require iTunes for major updates (iOS 4 to iOS 5) and do patches for minor ones (iOS 4.1 to iOS 4.2, or iOS 4.1.1 to iOS 4.1.2). This would result in smaller updates and remove the need to backup and restore. Except for...
  4. Failed updates. If something goes wrong and you're connected to iTunes, in the worst case scenario you can just restore (or even go into DFU mode and restore). If you're out and about, doing an OTA update, and something goes wrong, your device is effectively dead unless and until you can get back to your iTunes PC.

The Jailbreak factor

When Apple began doing carrier file updates OTA, it became an immediate concern for unlockers. While that hasn't turned out to be a real-world problem yet, it doesn't mean it won't.

Since Jailbreak depends on exploits to inject code, and updates patch exploits, more frequent and more targeted updates could kill existing Jailbreak exploits faster.


OTA updates are a bright, shiny future for iOS. It would further dismantle the iTunes tether, give more freedom to users, and more flexibility to Apple. But with great power comes great responsibility -- to make it an easy, robust, and mainstream friendly solution. Apple is usually great at solving these riddles, but online has never been their forte. And OTA device updates need to be nailed.

(Yes, we really made it all the way through this article without once mentioning the giant new Apple Data Center in North Carolina -- can you believe it? Oh, wait...)

Have something to say about this story? Leave a comment! Need help with something else? Ask in our forums!

Rene Ritchie

EiC of iMore, EP of Mobile Nations, Apple analyst, co-host of Debug, Iterate, Vector, Review, and MacBreak Weekly podcasts. Cook, grappler, photon wrangler. Follow him on Twitter and Google+.

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Reader comments

TiPb Answers: Why over-the-air iOS updates matter


OTA updates suck. Well at least on Android. Or it could be that the software just sucks in general.

It's just rumors anyways. Verizon iphone is unique in that its only cdma iphone. This can be done more efficiently with one carrier.

Yep, go to Verizon, and while your phone is updating, you get a call. Oh, well, you can always hope that the phone still functions so you can try again. On the second try, you get another call (of course I AM assuming you have 2 friends)and there goes your update again. At this point, I bet 'ol ATT will be looking pretty good.

Good Point!!
Or, it'll just disable your phone for an hour and take half your battery like OTA updates do on blackberry

Wah wah wah. I had a BlackBerry on Verizon, which thrives on OTA (I practically never plugged it in) and this was NEVER a problem. Though by all means, keep whining... everyone cares what someone who's never tried it has to say :P

I would love this because I wouldn't have to download 3 updates of 500mb area in the last 2 months. It should be like OSX its a patch. That might be a bit nicer on jailbreakers. And if it just comes over the air I would have to worry less about it.

I didn't see one advantage to be honest. None of the updates are worth having on the go with too much risk something could go wrong and no backup.
Using a PC or Mac to manage a mobile device isn't a disadvantage. It's desired.

The amount of data used would depend on the size of the update, assuming Apple doesn't stick to MB + update files (and there's no reason they would) expect between 20~ MB. I have done OTA updates over 3G, and it's fine but if you are on a plan or hate waiting WiFi is desirable (note that OTA updates shouldn't force you to update ASAP on whatever network you are on at that moment).

I like the tethered iOS updates. If you aren't home when they do an iOS update, it's not the end of the world. Just wait until you get home. I don't know what the big deal is. Tethered iOS updates work and are proven. Additionally, if you save the old restore file that iTunes replaces with the new one for the new iOS version, then you have the ability to downgrade the iOS if needed. This would not be possible with OTA. If they are so hung up on alleviating the iTunes dependency, then allow untethered content and back-up syncs within your own WiFi network. Leave something as important as a firmware update to the proven and reliable tethered method. The relationship my iOS device has with iTunes through syncing, updating, and backing up is one the best advantages iOS has over Android in my opinion.

You keep painting the DRM on iDevices as something Apple uses only because evil Hollywood forces them to. That is simply false; Apple requires DRM on iBooks even when both the author and the publisher specifically request there be no DRM on the book. ( http://goo.gl/G3vpq )
That is not Hollywood locking you out of your paid content -- that is ALL Apple.

Single library was a recording industry/Hollywood demand for iTunes deal. You're much more fun when you read before griping at me :)

Right back at you -- my point was that Apple has embraced DRM all on their own, without any Hollywood prompting, and the same restrictions you dismiss with a "(Thanks Hollywood)" also apply to non-Hollywood content areas, at Apple's insistence.

And as my father once told me, when I remarked on his own penchant for griping...
"Other people bitch -- I educate"
;) :) ;)

You're blaming Hollywood for Apple not giving us file system access, which is all we'd need to deal with that issue of "the one to rule them all" media syncing. Sorry but Hollywood isn't that powerful. That's all Apple.

I think the will start offering, but hope they also allow us to continue to do so through iTunes as well

The current process you outlined in the article is not quite right. Updating does not wipe out the contents of the device. Updating simply replaces the OS files on the device with the new OS. All content and settings remain.
I've had to restore an iPhone or two from backup before, and it's not a quick process, updating is a painless and relatively quick process.

@TJ Draper, thanks for pointing this out. I was going to mention the same thing. Here's hoping the author corrects the error in the piece to reflect the proper procedure.

I like to think if it like the OS is a sheet and your files are a glass of water.
Apple are like ninjas and pull out the sheet and replace it the glass doesn't even move(sorta like your files are in a box, and apple are just changing the rug)

Yeah, but a successful update does not delete your data and can be performed on any PC with iTunes.

We as long as they also have the option to download and install the update ... it should be fine.. I dont trust Verizon on OTA updates.

The biggest problem with this is dependency upon the carriers for the update. It is the single largest area of dissatisfaction with Android. The iPhone has always been free of this carrier shackle and this is a step backwards.

Apple only sells one type of phone (two if you count the Verizon as a subtype) and doesn't allow anyone to change even the tiniest fragment of the "experience". So long as Apple sticks with this policy this is not an issue, because the carriers don't need to be any more involved than they currently are.

You fail to include the possibility that after iOS 5.0... ALL of our data may be syncing perpetually to the iCloud "Castle" thus negating the possible horrorshow outcome of accidentally wiping your phone while attempting an update abroad before taking the time to backup! HOLLA!

How does an OTA update affect the JB? I would think that it would allow me to still have it, unless of course it is the JB that has been patched?

The worst thing about tethered updates is when my computer (running Windows) goes to sleep trying to download the ridiculously large file. When I wake it up, it has to start downloading all over again. Why? How can a company get some stuff so right and other stuff so wrong?

The rolling updates is the part that seems very un-Apple. I would love to see them switch to patching just what has changed, but I cannot imagine Apple would put themselves in a situation where anybody else had control of when their software was available to their customers.
Somewhat ironic, considering that is exactly what they demand of App Store developers, but Apple has far more leverage over carriers than any App Store dev has over Apple.
I could see Apple allowing an OTA push as an optional convenience, while keeping the iTunes based one so there is always one Apple->customer direct route available.

OTA updates are awesome on Android. The device notifies you when the file has already downloaded to the device, so the wait time is transparent to the user.
I have received updates while traveling in Europe, Canada, and even got Gingerbread while I was in St. Lucia. None of these updates dinged me for roaming data, I assume that Google has an arrangement with the carriers to push data during the off peak hours.
I know a couple of older 3GS users who are still running iOS 3.x because they never connect to iTunes.

Here's MY problem with that scenario, how many times will you or I be able to re-sync to the cloud before data caps kick in? Due to my iPhone 3G dying in april last year, and me not wanting to "upgrade" to a 3GS, I lost my unlimited data. It's ok, I almost never come close to 2GB in a month, but if I sync music thru the cloud I could easily run up several hundred dollars in overages with my 16Gb iPhone 4. Now add in a couple 500Mb os updates...

OTA update for iOS would be disastrous, I just updated my Verizon iPhone to 4.2.8 and it was a 650 megabyte download, that's over half a gig and they want to send over 3G? That's insane!
OTA updates on Android are fine because they're 60 megabytes at the most and Blackberry updates aren't that big either. Why are iOS updates so huge even when it's such a minor update?

To answer a lot of mis-conceptions I'm seeing in this thread, I'll start with saying that some people here need to learn to use their brains to think a bit.
A) I think it's pretty obvious if this happened Apple would stop it's practice of forcing you to download the entire firmware every update, and instead just release it as patches similar to Android. To all the people saying "ZOMG 650 Meg updates on 3G end of world approaching!!!!", I respond with, durrrr.
B) As has been the case for a long time, carriers don't charge for data usage for updating phones. I think a little bit of rational thought would lead most people to the conclusion that this would probably also apply to Apple.
C) to the guy who said "there is more important updates needed to iOS". Again, durrr. That is the reason why companies like Apple hire more than one employee, so they can work on more than one thing at a time.
I don't know why I read forums..... I just get angry at stupid comments.

I would have thought that the number one ixx blog would know that you can update an iPhone / iPad from any computer running iTunes. You don't need the machine that you sync to, just access to iTunes.

I hate OTA because with the OTA they US carriers if they allow it are going to take their sweet sweet time testing the update. Also I prefer a complete OS update because that way it is more stable and robust. These updates better be free of data charges because 500MB is a lot I guess I am going to have to wait for the major updates to update or hopefully I can continue updating my phone the I do now chances are they will because the iPod touch needs to get the point updates via the PC.
I just hate OTAs and just look at HP web os, android and Windows Phone so many problems that I don't want and if an update is not important enough till I home then it is not a big deal.

Article isn't fully accurate. You can upgrade any iPhone on any computer, not just the one you sync to. I routinely upgrade my iPhone at work (and those of colleagues) when an upgrade comes out. I skip the backup because I do those at home. I don't want over the air backups because they would be slow and unreliable -- and Apple wants to perform a verification afterwards over the wire. I'm surprised people complain about or even notice this as a "problem," as it's not like we get an OS upgrade every week.

I really don't care whether they introduce OTA updates or stick with the old method -- updates only come along a few times a year, what's the big deal…?!
I'd rather have them introduce wireless syncing, that's something I do all the time and having to plug in my iPad and iPhone every time is a pain in the *ss…!

I believe OTA updates would be good. I have a Palm phone and all updates are OTA. These updates affect only the OS and do not ever change, modify, or delete any applications or related data, nor do they affect any other files and music stored anywhere on the phone so there is no such thing as having to backup and restore just to do an update. I am not sure why Apple never got on this sooner as it would make the backup and restore requirement a thing of the past. A simple OS update does not require any need to remove and restore applications as they are separate files stored on the device which have nothing to do with the OS file being updated. The OTA update concept will solve this and allow much more flexibility in device updates, and as for rollouts, Apple can choose to make their updates immediately available via the OTA update process just like they do using the current process. There is no requirement that they be "rolled out" over time or in any certain way, and there is no requirement that would force Apple to delay any updates to any devices. The OTA update process is a good thing, and I believe it would work very well.

I think we can all agree that OTA updates are pretty much useless, until Apple pegs them. The way they are handled now by the idiots at Google are laughable. Once again, Apple will show everyone how it should have been done from the start. That is, if it even can be done properly. If not, then we know that it can't be done. Besides, we already have a perfect system in place.

OTA updates are meh in my book. Sorry but it is so un-necessary to update OTA to me. I know all users are not like me, in fact I'm probably a minority. However by bundling new features Apple has now gotten everyone to think updates are a must even if it's a little point upgrade. I was JBen and unlocked on my 3G for years and I wouldn't update my firmware until there was a new Pwnage Tool out which means I skipped updates until 2 firmware versions sometimes. Guess what my phone and apps alwyas worked. I would sometimes update when apps started only being compatible with the newer firmware. I think instead they should concentrate on giving the ability to sync OTA how many times do you sync a day? How many times do you update/upgrade?

Couldn't Apple meet in the middle by releasing most of their native apps (safari, mail, clock, etc.) /though/ the app store so that they could be independently updated without requiring a full firmware update? That would allow Apple to keep up with the bugs and exploits (especially for Safari).