AT&T covers 8 more markets with LTE service, including Honolulu
The Apple iPhone 5 supports 4G LTE service
AT&T's 4G LTE service is now available in the Detroit metro area, Portland, Seattle, Honolulu, Pittsburgh, Sacramento, Birmingham and Memphis. In addition, LTE coverage has been expanded tin Miami-Dade County. LTE service offers 4G data speeds as much as ten times faster than 3G. That, of course, is just a guideline and actual speeds can be higher or lower. For example, on Tuesday some LTE users in Detroit were able to download data at speeds of around 54Mbps.
source: AT&T via AndroidCentral