BFR

Technical Explanation

Upon declaring beam failure, the UE does not trigger costly Radio Link Failure (RLF). Instead, it identifies a healthy candidate beam (RSRP > Qin), selects a dedicated contention-free PRACH resource associated with that candidate beam, and transmits a Beam Failure Recovery request. The gNodeB replies with a DCI grant within a dedicated search space, restoring service in milliseconds.

Key Functions

• Recovers lost beam alignment without triggering disruptive RLF or RRC re-establishment
• Transmits dedicated contention-free PRACH preamble on healthy candidate beam
• Restores multi-gigabit communication within 10 to 20 milliseconds