LTE-U is commercially available and currently in use on a limited scale for wireless internet service. The main (and almost only) manufacturer of base stations

LTE-U is commercially available and currently in use on a limited scale for wireless internet service. The main (and almost only) manufacturer of base stations and clients is a company called Baicells. While LTE-U does have some advantages over WiFi for WISP use (e.g. better handling of a large number of clients per AP), the higher cost (around ~$9k for an LTE-U eNodeB compared to as low as $500 for a WISP-grade 5GHz WiFi AP) and scarcity of vendors means that it's not very commonly used. We'll see if that changes over time, but WiFi has a huge amount of inertia in that space so it seems difficult for LTE-U to catch up considering that the power levels are limited to such an extent that it doesn't have a huge range advantage over WiFi with good antennas. In fact, just looking at Baicells it seems that they offer fewer models for LTE-U than they used to, so they may be finding that sales aren't enough to keep up the product line.