Radio Link Failure Detection in HF-NR Beam Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency (HF) radio link failure detection is challenging in new radio access systems due to susceptibility to shadowing and the need for adaptive beamforming, which can lead to intermittent connectivity and delayed base station detection, especially in high-traffic and mission-critical applications.
Innovation Solution
The implementation of a UE apparatus with a beam tracker, recovery module, and failure handler that detects physical layer problems on serving beams, performs recovery procedures supervised by timers or count numbers, and declares radio link failure when recovery is unsuccessful, using dedicated or random access procedures for initial beam alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high directional transmissions through beamforming are used to compensate propagation loss, then antenna gain is improved, but vulnerability to propagation environment and intermittent connectivity worsen
Solution Approach 1:
The patent segments the beam management into multiple independent components: beam tracking for maintaining current beam quality, beam switching for transitioning to alternative beams, and separate recovery procedures for different failure scenarios. This segmentation allows the system to address connectivity instability through targeted interventions without compromising the high gain benefits of directional beamforming.
Solution Approach 2:
The patent implements preliminary actions by establishing multiple candidate beams in advance and maintaining beam tracking information before failures occur. The system proactively monitors beam quality metrics and prepares recovery beams beforehand, enabling rapid response to connectivity degradation without waiting for complete link failure.
2Productivity
If adaptive beamforming at large scale is implemented, then transmission capability is improved, but base station detection delay during cell search and handover worsens
Solution Approach 1:
The patent applies preliminary action by performing beam tracking and candidate beam identification during normal operation, so that when cell search or handover is needed, the system already has current beam information and alternative options ready. This eliminates the need for exhaustive angle scanning during critical transitions.
Solution Approach 2:
The system continuously feedbacks beam quality measurements and tracking information from the UE to the base station, enabling real-time adaptation of beam directions and rapid detection of optimal beams during cell search and handover procedures, significantly reducing detection delays.
3Productivity
If multiple beams are used to cover the cell, then capacity is improved, but complexity of radio link quality detection and beam management worsens
Solution Approach 1:
The patent segments beam management into distinct functional modules: beam tracking for quality monitoring, candidate beam identification for alternatives, and separate recovery procedures. Each module handles specific aspects independently, reducing the overall complexity of managing multiple beams while maintaining high cell capacity.
Solution Approach 2:
The UE autonomously performs beam quality detection, candidate beam identification, and recovery procedure selection based on pre-configured criteria and measurements. This self-service approach reduces the signaling overhead and control complexity required for multi-beam management while maintaining accurate radio link quality detection.
4Reliability
If frequent beam switching is performed to maintain connectivity, then reliability is improved, but triggering of radio link failure conditions and unnecessary recovery procedures worsens
Solution Approach 1:
The patent implements beforehand cushioning by establishing hysteresis margins and threshold offsets in beam quality evaluation. Before triggering a beam switch or failure declaration, the system checks whether the quality degradation exceeds a predetermined margin, preventing unnecessary switching due to temporary fluctuations and cushioning against false failure conditions.
Solution Approach 2:
The system uses continuous feedback of beam quality measurements to dynamically adjust switching decisions. By monitoring quality trends over time and comparing against adaptive thresholds, the system can distinguish between temporary degradations and genuine failures, reducing false triggering of recovery procedures while maintaining reliable connectivity.
Data Source
AI summary
Apparatus and methods are provided to detect radio link failure in a NR access system. In one novel aspect, the radio link failure is detected upon detection of one or more radio link failure conditions on the serving beam. In one embodiment, the physical layer problem is considered as detected when one or more predefined events occur for a number of consecutive times on the serving beam. In another embodiment, the UE further considers potential recoveries to avoid frequent triggering of the radio link failure condition. In one embodiment, the UE performs the initial alignment procedure to recover the connection. In one embodiment, UE performs the initial alignment procedure without performing radio link recovery on the serving beam. In other embodiments, the UE performs the initial alignment procedure after performing radio link recovery on the serving beam and/or selects one or more beams for initial beam alignment.