Beam Failure Recovery Timing Using Response-Based Subcarrier Spacing

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Solution Overview

Problem

In wireless communication systems, determining the subcarrier spacing (SCS) for beam resetting during beam failure recovery (BFR) is challenging when different component carriers have different SCS configurations, leading to inconsistencies in beam resetting timing.

Innovation Solution

A user equipment (UE) transmits a TRP-specific BFR MAC-CE indicating a new beam for beam failure recovery, receives a TRP-specific BFR response, and determines the SCS for resetting based on the response's SCS, which differs from the failed TRP's SCS, to perform a transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different component carriers use different SCS configurations, then each carrier can be optimized for its specific requirements, but beam resetting timing becomes inconsistent and difficult to determine

Engineering Contradiction:

ImproveSCS configuration flexibilityVSAvoidbeam resetting timing consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces the BFR response message as an intermediary carrier that conveys the SCS configuration for beam resetting timing. When the SCS of the failed TRP differs from the current carrier's SCS, the BFR response message carries the alternative SCS value, serving as a mediator to resolve the timing inconsistency. This allows the UE to determine correct beam resetting timing even when component carriers have different SCS configurations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If beam resetting timing is determined based on the failed TRP's SCS, then timing accuracy for that TRP is improved, but inconsistency arises when the current carrier has a different SCS

Engineering Contradiction:

Improvebeam resetting timing accuracyVSAvoidtiming determination complexity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The system enables self-service timing determination by embedding the SCS configuration directly in the BFR response message. The UE autonomously extracts the SCS value from the BFR response and uses it to calculate beam resetting timing without requiring external coordination or complex lookup procedures. This simplifies the operation while maintaining timing accuracy for the failed TRP.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12574765B2Resetting a beam based at least in part on a subcarrier spacing

Publication Date: 2026.03.10 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to a network entity, a transmit receive point (TRP)-specific beam failure recovery (BFR) medium access control control element (MAC-CE) indicating a new beam for the UE based at least in part on a TRP with beam failure. The UE may receive, from the network entity, a TRP-specific BFR response based at least in part on the TRP-specific BFR MAC-CE. The UE may determine a subcarrier spacing (SCS) for a TRP-specific BFR beam resetting timing based at least in part on an SCS associated with the TRP-specific BFR response being different than an SCS associated with the TRP with beam failure. Numerous other aspects are described.