1. ralphdash's Avatar
    You can update to ICS using the LT28H firmware update and still keep LTE. (NOTE: YOU ARE DOING THIS AT YOUR OWN RISK YOU HAVE BEEN WARNED.)

    1. Backup all your things.

    2. Download ICS and Flashingtool

    3. Install Flashingtool (You might have to install the drivers which are located in the root of your HD in a folder called Flashingtool when installing just select all the phone models.) Reboot your computer after installing.

    4. Open Flashingtool

    5.Get your phone read to flash by turning it off then holding down the volume and inserting the usb cable you'll see a green light turn on.

    5. It should recognize your phone click on the Flash.

    6. Look for were you saved the unziped Firmware.

    7. In order to keep LTE you have to uncheck mark Wipe Data, Wipe Cache. You have to keep a checkmark on Wipe Applog, and check Exclude Baseband.

    8. Your phone should flash and when it finishes unplug it and boot it manually it will not reboot on it's own.

    9. Your phone will boot up it might take a while.

    10. It will feel sluggish so I suggest you reset the phone once you have it booted.

    11. If you do reset the phone and erase everything you'll need the AT&T APN settings.
    Name: ATT PTA
    APN: pta
    MMSC: http://mmsc.mobile.att.net
    MMS Proxy: proxy.mobile.att.net
    MMS port: 80
    MCC: 310
    MNC: 410
    Auth: none
    APN type: default,mms,supl,hipri

    (Note it will change your Model Number to LT28h)
    08-13-2012 02:48 PM