NEW YORK � T-Mobile US and AT&T are both testing use of unlicensed spectrum at 5 GHz, and the results of field tests are intriguing. T-Mobile US reported that it achieved 741 megabits per second speeds in the downlink using License-Assisted Access and 80 megahertz of aggregated spectrum; AT&T laid claim to speeds of around 650 Mbps, according to fiercewireless.com.�
T-Mobile US indicates that its network now supports the use of LTE-U (LTE using unlicensed spectrum) in some locations in Bellevue, Wash.; Brooklyn, N.Y.; Dearborn, Mich.; Las Vegas; Richardson, Texas; and Simi Valley, Calif., with more sites coming on line through this year. AT&T launched its test of LTE Advanced Pro technologies in April in Austin, Texas, and plans to have support in more than 20 major metro areas by the end of 2017, including Indianapolis; Atlanta; Boston; Chicago; Los Angeles; Nashville, Tenn.; and San Francisco, according to the same article.
The T-Mobile US roll-outs of LTE-U also use LTE in the 5 GHz unlicensed band using a proprietary�duty-cycling approach for spectrum sharing, rather than LAA�s listen-before-talk strategy.
LTE-U has been met with skepticismin the Wi-Fi community, who worry that the technology will lead to interference with existing and future Wi-Fi deployments at 5 GHz.