I have a tri band phone, so i wont get LTE till it is fully lit up, with the csfb installed. it's been said that generally its anything marked yellow on the map, but that hasnt always been the case.
people have detected LTE on sensorly where I am from as far back as a year ago, along the lakefront, but not sure from where since there are no LTE sites complete on the map near me, just 3g.