Through carrier aggregation, LTE in unlicensed spectrum is combined with LTE in the licensed band, which becomes the anchor carrying all of the control and signaling information. Because of licensed anchor and other features, LTE-U and LAA offer better efficiency and robust mobility. For operators with carrier Wi-Fi deployments, LTE – Wi-Fi link aggregation (LWA) utilizes both 2.4 GHz and 5 GHz to bring similar benefits.
LTE-U, along with LWA, is supported by the Qualcomm® Snapdragon™ 820 processor with X12 LTE, as well as the discrete Snapdragon X12 LTE modem. This is a good example of how multiple technologies are required to make the best use of all spectrum: LTE Advanced carrier aggregation, tri-band Wi-Fi with 802.11n, 802.11ac MU-MIMO and 802.11ad, and now also LTE-U and LWA.