One of my favourite things about the iPhone is that it’s fairly painless to throw another SIM card into your iPhone, and have all of your carriers settings just work (internet, MMS, voicemail, and tethering if your carrier allows it). The way this magic works is that Apple actually has the settings for all of the official iPhone carriers preloaded into iOS. If you throw in a SIM from a supported carrier, the settings are simply loaded and away you go. These are referred to as carrier bundles (or, carrier settings according to Apple).
Carrier settings updates are small files (about 10 kb) that are installed on your iPhone or iPad (Wi-Fi + Cellular models). Carrier settings include updates to Access Point Names (APNs), MMS settings, features such as tethering, and default apps such as Stocks, Maps, and Weather.
On your iOS device, they live at
/var/mobile/Library/Carrier Bundles/ – bundles that have been updated with iTunes, or pushed over the air
/System/Library/Carrier Bundles/ – stock bundles that ship with iOS
On your computer side, they can be found at
~/Library/iTunes/iPhone Carrier Support/
If you haven’t ever had iTunes prompt you about a carrier update, this folder probably won’t exist.
Carrier bundles themselves are simply .zip archives, but with a .ipcc extension instead. They’re named after your carrier, and may also say whether they’re for your iPhone or iPad (Telstra_au_iPhone.ipcc)
Since there doesn’t seem to be an easy and straight through guide for unlocking your iPhone, thought I’d quickly throw something together.
Unlocking your iPhone is great. It allows you to put in other carrier’s SIM cards. This is great if your telco isn’t cutting it and wish to move networks and keep your phone. It’s also handy for when you travel; picking up an international SIM is much cheaper than using your local SIM card and then roaming overseas. Oh, and it increases the resale value; anybody on any carrier in the world can use it now!
Around the world, most telcos will allow you to unlock your iPhone. Here in Australia, all telcos will unlock a post-paid iPhone for free. If you’ve picked up an iPhone (3GS) prepaid, you’ll have to cough up an unlocking fee. Overseas, companies such as AT&T will only unlock your phone when you’re at the end of your contract (officially). Apple has a list of carriers that will unlock your iPhone on their website.
If you contact your carrier today, chances are they’ll tell you it may take a few days (up to 72 hours) for things to happen, and at that point you need to connect to iTunes and restore. However, as of iOS 5, and the new PC-free initiative and methods, unlocking has become much easier. There’s no need to do a great big backup, and then restore just to unlock your phone.
After starting construction work on their LTE network back in May 2010, Telstra finally started trialling their network, starting with business customers in August, and finally launching it for consumers with the Sierra AirCard 320U USB modem. While only officially offered on a 24 month contract, it’s been available for purchase outright (for ~$299AUD). Following on from the AirCard, the HTC Velocity 4G was released in late January. More recently, they also just launched the first LTE tablet – the Samsung Galaxy Tab 8.9 running Android, and, another USB modem – the ZTE MF821.
What makes the MF821 special for people wanting to buy it, is it’s being targeted towards the prepaid market. As mentioned above, it’s always been possible to purchase the AirCard 320U outright and then throw a prepaid SIM in there, $299 was quite pricey for the average joe. Telstra have priced the MF821 at $129, which in my opinion is a steal. You also get 3GB to use in the first 30 days from activation.
Picking one up on launch day was tricky – while the product was launched Wednesday with an availability of ‘today’, only 2 of the 5 Telstra stores I visited had them in stock, let alone had heard of them. After finally hunting one down, I was in business. The store assistant even offered to activate it for me on the spot.
If you haven’t heard of LTE (also known as 4G) before, it’s the next generation of wireless networks – in real world situations it’s at least twice as fast as 3G. Telstra have been rolling out this network to compliment their existing Next G 3G network in capital cities, until enough spectrum is available to roll it out to the rest of Australia.
Have you ever looked at your carrier name in the status bar of your iPhone? Chances are you have. If you’ve ever wondered where this actually comes from – this is really just an image contained in the carrier’s bundle of settings.
This makes it much easier for this to be customised or changed. Carriers can (naturally) and do change how their network appears – Optus changed from ‘OPTUS’ in firmwares lower than 4.x to ‘YES OPTUS’ in iOS 5. Telstra choose to display ‘3TELSTRA’ as ‘Telstra’, (and likewise for 3 – choosing to appear as ‘3’ instead of 3TELSTRA)
This is also handy for users – carrier bundles are easily edited and tweaked by users and can be deployed semi-officially – the same way carriers can deploy themselves on the side.
While in iOS 5 many of the actual carrier configuration data is signed and will refuse to work if the signature is broken – the images are free rein. You can do whatever you want here.