T-Mobile first in U.S. to operate LTE-U network
That means Carrier Aggregation, 256 QAM (Quadrature Amplitude Modulation) and 4x4 MIMO (Multiple Input Multiple Output) are being employed on LTE-U. Because LTE-U uses high frequency airwaves, it has limited range which means it needs to be deployed in urban areas. Earlier this year, T-Mobile said that it might use LTE-U to debut its Gigabit LTE services.
In addition, T-Mobile field tested License Assisted Access (LAA). The test showed speeds of 741Mbps using 80MHz of aggregated spectrum. LAA allows more carrier aggregation than LTE-U. With LAA, T-Mobile can combine more licensed and unlicensed bandwidth. This increases the capacity that T-Mobile can offer its customers. T-Mobile will be densifying its network later this year. This will include the use of small cells, which carry LAA functionality. LAA and LTE-U use underutilized spectrum and other users on the same band, including Wi-Fi users, are unaffected.