The use of millimeter-wave spectrum has evolved in the 5G era, and these high-band airwaves are playing significantly different roles in current networks than they have in previous generations of cellular technology.
High-band frequencies used to primarily appear in mobile networks as point-to-point backhaul links, which were often relied upon by public safety and other private networks, as well as in some cases for backhaul of consumer-facing cellular networks. Commercial network backhaul systems operate in spectrum up to 90 GHz.
