More news on the Nexus 4’s 4G LTE capabilities, as some folks have been able to connect to AT&T’s 4G LTE network, through band 4 (AWS spectrum). The frequency in question is currently used in a small amount of markets by AT&T, but it’s tough to tell if or where you’ll get it, since AT&T doesn’t primarily use band 4 for its LTE. We aren’t sure if they are simply using band 4 in markets that they don’t have enough band 17, or what the deal is. Either way, you should probably test your phone to see if it can pick it up. It should be noted that band 4 is the same LTE frequency that the Nexus 4 connected to in Canada.
In order to test, jump into the dialer and type *#*#4636#*#*, tap “Phone Information,” and then scroll down until you see the pull-down menu that reads “WCDMA.” Toggle that menu to read “LTE/GSM/CDMA auto (PRL). Once completed, you will know pretty quickly if you have picked up AT&T’s LTE as the data icon will change from a “H” to “4G.”
If you happen to live in certain areas of Phoenix, Los Angeles, Dallas, Chicago, Oklahoma, and a few others where the frequency is in use, you should jump on this immediately.
For more info and how to possibly get it working on your device, hit up the XDA threads below.
Via: XDA  | Android Police