Updated X2: The guide has been updated to fix some of the instructions.
As the iPhone 5 launched on T-Mobile’s network, existing AT&T unlocked iPhone 5 customers received a carrier update to enable the LTE signal. As it turns out, in some cases the carrier update added something good with LTE, but negatively affected the signal and speeds achieved on the company’s refarmed PCS 1900MHz network.
Well, there’s some good news thanks to our friends @joe012594 and @cooldayr2 who have successfully “hacked” the carrier update in the hopes of boosting those speeds. As it turns out, their efforts were not in vain and they achieved their goal by “increasing the amount of bandwidth allowing for better throughput of data and data connection.” There’s a “tech talk” section at the tail end of the instructions explaining what was done and why it was necessary. The bottom line is these two guys succeeded in aiding those customers who found their service worse off in a post-carrier update world. The good news is this update works on both the official T-Mobile variants of the iPhone 5 and the AT&T/unlocked model so all iPhone 5 owners on T-Mobile should see speed improvements.
Follow the instructions below (carefully mind you) and keep in mind this file works for both jailbroken and non-jailbroken users. If you encounter any issues the official carrier update is available below and you can go right back as if nothing had ever happened.
As a quick note to go along with this as @joe012594 is the very some person who provided the list of instructions for jailbroken users to enable LTE on their jailbroken iPhone 5 smartphones at the end of March.
Be sure to send these guys some love on Twitter or in the comments below for their help and hard work in making sure this was something all AT&T unlocked iPhone 5 T-Mobile customers can enjoy.
Since many unlocked iPhone 5 users report weakened signal on the refarmed 4G HSPA+ and many iPhone users (unlocked or official T-Mobile versions) report slower data speeds, I have spent many hours for many days doing research on what could be done to fix the issue. After partnering with @cooldayr, we both have come up with the best possible solution to fix this issue. Below is a fix we have provided for all iPhone 5 users on the T-Mobile network. This will not take away any features added by the official carrier update nor does it require a jailbreak, however, we have made it user friendly for both jailbroken and non-jailbroken users. If you have any issues, please tell Joe at twitter.com/joe012594. Thanks!Non-jailbroken users:1. Plug your iPhone 5 into iTunes and backup the device so you won’t lose anything, just in case. ;)2. In the device itself, tap the “Settings” app and navigate to “General >Reset > Reset Network Settings”3. Once you have done that, the iPhone will auto reboot.4. Download the hacked carrier update here:http://www.4shared.com/file/WF0uqJL-/TMobile_US_iPhone_Hack.html5. Now you’ll to go ahead and enable iTunes to except custom carrier bundles, if it’s not already.6. Windows users, you will need to open command prompt and type the following and enter it in:64 bit: cd “C:\Program Files (x86)\iTunes” then type: iTunes.exe/setPrefInt carrier-testing 132 bit: cd “C:\Program Files\iTunes” then type: iTunes.exe /setPrefInt carrier-testing 1Mac users you will need to open terminal and type the following and enter it in:Mac: defaults write com.apple.iTunes carrier-testing -bool true7. After this has successfully been entered in restart iTunes8. Click on the tab for your iPhone 5 and click “Update” or “Check For Update” while holding down the Alt / Option key for Mac users and the Shift key for Windows users. Navigate to where you downloaded the hacked carrier update file named “TMobile_US_iPhone.ipcc,” and select it then click Open.9. The carrier update should now successfully be installed. Restart your iPhone 5 for any changes to take effect.10. If you encounter any problems or wish to revert back just download the file below and repeat the above steps only with the default file instead.Jailbroken Users:1. Download the file to your device through iFile here:2. Unarchive the files and copy the file name “overrides_N41_N42.pri” then navigate to var/mobile/Library/Carrier Bundles/TMobile_US.bundle and paste it into the folder replacing the original .pri file.3. Reboot your device for changes to take effect.4. If you encounter any problems or wish to revert back just download the file below and repeat the above steps only with the default file instead.Tech talk:This hack enables Release 9 DC-HSPA+ on the iPhone 5. Though T-Mobile has not yet upgraded their network to support these speeds, the device itself becomes more open to an increased amount of bandwidth thus allowing for better throughput of data and data connection. The average increase has been 3mbps to as high as 8mbps on the downlink. This hack also includes a fix to any and all iPhone 5 users who have experienced degraded/weakened signal over the past couple of months on the PCS and/or AWS bands, though a lot of this could be due to the eminent release of LTE in many upcoming markets as this is normal. The issue was due in part to the carrier update. It set the band preference for HSPA+, even if your iPhone 5 doesn’t support it, to AWS which can cause conflictions and problems for the devices that don’t support that band. The setting has been set to the default “auto” setting and should help the 4G signal perform a bit better, whether you’re iPhone 5 is PCS only or dual PCS/AWS. For those with an iPhone 5 that supports AWS, this hack will also help you as well as it will connect to the strongest tower (PCS and AWS) rather than the preferred type of tower. Enjoy!