General principles of beam management in mmwave

General principles of beam management are in mmwave are as follow :

P1: Beam Establishment (initial gNB beam acquisition)

Beam sweeping is used to cover a given area (e.g. 120° span)

• On gNB side wide beam sweeping is used, UE detects best beam
• In this procedure wide beams are used both on gNB and UE sides

 P2: gNB beam refinement & tracking (gNB Tx)

• gNB refines beam (e.g, sweeping narrower beams within a wide beam)
•  UE switch from wide to narrow beam or change of narrow beam

 P3: UE beam refinement & tracking (UE Rx)

• gNB fixes a beam, UE measures currently used gNB beam and selects a narrower receiver beam
• Wide beam can be used as initial access and fall-back in case of loss of narrow beam