We were curious what markets we would start seeing modifications requests come in for new antennas on existing cell towers for 5G and LTE-U installations. These trials in most cases will require new antennas with new frequency bands. So we created the map that you can see below- or see the online version of the 5G and LTE-U Test Market map. 
US 5G and LTE-U Test Markets by Wireless Carrier- 2016