If you are still on firmware P907AUCU1AND7 from AT&T SM-P907, you will need to upgrade to P907AUCU1ANK2 before P907AUCU1BOH3.
-Putting the updates on your SD Card,
-Boot into recovery ( Power+ Volume UP )
-Apply update from external storage and select the update zip.
This is P907AUCU1ANK2 KitKat OTA update.
https://drive.google.com/file/d/1lju...ew?usp=sharing
This is P907AUCU1BOH3 5.1.1 Lollipop OTA update.
https://drive.google.com/file/d/18Sv...ew?usp=sharing
Important: back up your data as each update it will reset your tablet.
The second update might take 5 to 10 minutes to start, so be patient when it unzip the file.