The difference is that in 4G the ability may be available in some areas and not in some areas in ad hoc manner. In the case of 5G 3GPP is committed to unlicense

The difference is that in 4G the ability may be available in some areas and not in some areas in ad hoc manner. In the case of 5G 3GPP is committed to unlicensed spectrum. In 4G, instead of LTE-U you are getting LTE-LAA (License Assisted Access). You are basically getting the permission from carrier or from some alliance that buys licenses depending on the country, city or region. 5G will support: LTE-U/LAA as well as stand-alone NR-U (stand-alone operation in unlicensed spectrum).