Just prior to the official launch of the iPhone, T-Mobile issued a carrier update to enable LTE, improve battery performance and add Visual Voicemail support . The only problem is that some users were reporting slower speeds after the update. TmoNews reports that two well known cellular programmers, @joe012594 & @cooldayr2, have successfully modified the carrier update to “increase the amount of bandwidth allowing for better throughput of data and data connection.” That means you should be able to download apps quicker, browse the web faster and have a better overall experience on your T-Mobile iPhone after applying the patched carrier update.

Before and after speed comparison (via TmoNews):

The update does not require your iPhone to be jailbroken, preface by the coders and instructions for the hack are below. As always, please be sure to do a full backup of your iPhone prior to modding it in any way.

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 done many hours for many days doing research on what could be done to fix the issue. After partnering with @cooldayr2, we both have come up with the best possible solution to 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 user friendly for both jailbroken and non-jailbroken users. If you have any issue, 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.

2. In the device itself, tap the “Settings” app and navigate to “General > Reset > Erase all content and Settings”

3. Once you have done that, the iPhone will auto reboot.

4. Download the hacked carrier update here: http://dc372.4shared.com/download/WF0uqJL-/TMobile_US_iPhone_Hack.ipcc?tsid=20130511-014618-1518f967

5. Once downloaded, your iPhone will boot up into iTunes. Before you do ANYTHING, make sure to decline any and all prompts to update carrier settings. Just choose to “Restore from backup” and let it run.

6. Once your iPhone has booted up once again, it will place all of your personal content back into the Phone. While it’s doing this we’re going to go ahead and enable iTunes to except custom carrier bundles, if it’s not already.

7. 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 1

32 bit:cd “C:\Program Files\iTunes” then type: iTunes.exe /setPrefInt carrier testing 1

Mac users you will need to open terminal and type the following and enter it in:

Mac:defaults write com.apple.itunes carrier-testing -bool true

8. After this has successfully been entered in, click on the tab for your iPhone 5 and click “Update” or “Check For Update” while holding down the Alt / Optionkey 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: http://dc372.4shared.com/download/WF0uqJL-/TMobile_US_iPhone_Hack.ipcc?tsid=20130511-014618-1518f967

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.