Beam Failure Reporting via MAC Control Element
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Solution Overview
Problem
In 5G New Radio systems, when a beam reception fails in a secondary cell without a Physical Random Access Channel (PRACH), user equipment (UE) cannot timely notify the base station, leading to potential call drops and service quality degradation. Configuring PRACH for each secondary cell or using the Physical Uplink Control Channel (PUCCH) of the primary cell increases radio resource reservation and network deployment complexity.
Innovation Solution
Encapsulating the identifier of the secondary cell where the beam reception fails and the corresponding candidate beam into a Media Access Control (MAC) control element, which is then transmitted using resources from other cells, thereby avoiding the need for PRACH and PUCCH configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PRACH is configured for each SCell to enable beam failure reporting, then beam reception failure can be reported timely, but radio resource reservation increases and network deployment complexity increases
Solution Approach 1:
The PCell's PRACH resources are configured to serve multiple purposes: both for random access in the PCell and for beam failure reporting in SCells. The UE determines whether to use PCell PRACH for SCell beam failure reporting based on configuration parameters, making the PCell PRACH a multi-functional resource that reduces overall network complexity while maintaining reliable beam failure reporting capability
Solution Approach 2:
The patent merges the beam failure reporting function with the existing PCell PRACH resources. Instead of creating separate PRACH resources for each SCell, the solution combines multiple reporting functions into the PCell's PRACH infrastructure, reducing radio resource reservation overhead and simplifying network deployment
2Reliability
If PUCCH of PCell is used to report beam reception failure, then reporting can be achieved, but PUCCH overhead increases and radio resource reservation increases
Solution Approach 1:
The PCell's PUCCH resources are configured to serve dual purposes: carrying normal uplink control information and reporting SCell beam failure detection. The UE uses a specific PUCCH format and resources in the PCell to report beam failure in SCells, making the PUCCH resource multi-functional and avoiding the need for dedicated reporting channels in each SCell
Solution Approach 2:
The patent combines beam failure reporting with existing PUCCH resources in the PCell. By merging the reporting function into already-allocated control channels, the solution avoids increasing overall radio resource reservation while ensuring reliable failure reporting
3Reliability
If dedicated preamble is configured for PCell, then beam reception failure can be reported, but this solution cannot be applied to SCell without PRACH
Solution Approach 1:
The patent extends the dedicated preamble mechanism from PCell to SCell by allowing the PCell's dedicated preamble to serve both cells. The gNB configures the UE with a dedicated preamble for PCell that can be used for beam failure reporting in both PCell and SCell, making the preamble resource universal and enabling SCell adaptability without requiring separate PRACH configuration
Data Source
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AI summary
A reporting method for a beam reception failure, and a user equipment, a medium and a system. The reporting method for a beam reception failure comprises: acquiring an identifier of a secondary cell where a beam reception failure occurs; selecting another beam as a candidate beam in the secondary cell where the beam reception failure occurs; and encapsulating the identifier of the secondary cell where the beam reception failure occurs and an identifier of the candidate beam as an MAC layer control factor, and sending the MAC layer control factor to a base station via the other cell, wherein the other cell is: a primary cell, a primary and secondary cell, or the other secondary cell where no beam reception failure occurs. By means of the above-mentioned solution, an identifier of a secondary cell where a beam reception failure occurs and the corresponding candidate beam thereof can be reported to a base station without occupying a PRACH and a PUCCH.