UE Random Access Procedure Selection
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Solution Overview
Problem
The increasing demand for radio access in next-generation wireless communication systems, such as 5G NR, requires further improvements in Random Access (RA) operations to efficiently manage UL resources and reduce latency.
Innovation Solution
The proposed solution involves a wireless communication method and User Equipment (UE) that dynamically handle RA operations by selecting between 2-step and 4-step RA procedures based on available UL resources and pending data, allowing for early termination of RA procedures when sufficient resources are available.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE performs complete RA procedures (2-step or 4-step) to ensure reliable UL resource allocation, then the reliability of resource allocation is improved, but the latency and procedure duration increase
Solution Approach 1:
The patent applies dynamics by making the RA procedure length adaptable rather than fixed. The UE dynamically selects between 2-step and 4-step RA procedures based on real-time assessment of UL resource availability and buffer status. This dynamic adaptation allows the system to choose the shorter 2-step procedure when resources are available (reducing latency) while falling back to the more reliable 4-step procedure when resources are insufficient (maintaining reliability).
Solution Approach 2:
The patent changes the parameter of RA procedure steps from a fixed value to a variable that can be adjusted based on system conditions. By monitoring UL resource availability and buffer status, the UE modifies the RA procedure parameters (selecting 2-step vs 4-step) to optimize the trade-off between reliability and latency, thereby resolving the technical contradiction.
2Quantity of substance
If the UE initiates RA procedures to request UL resources when PUCCH resources are unavailable, then the UL resource availability is improved, but the network resource utilization efficiency decreases due to unnecessary procedures
Solution Approach 1:
The patent applies preliminary action by having the UE check UL resource availability and buffer status before initiating RA procedures. The UE proactively assesses whether UL resources are needed and whether PUCCH resources are available, and only initiates RA procedures when truly necessary. This preliminary check prevents unnecessary RA procedures, thereby improving network resource utilization efficiency while ensuring UL resources are available when needed.
Solution Approach 2:
The patent uses feedback mechanisms where the UE continuously monitors UL resource availability, buffer status, and PUCCH resource availability. Based on this feedback, the UE makes informed decisions about whether to initiate RA procedures or use alternative methods (like PUCCH-based SR). This feedback-driven approach optimizes the balance between ensuring UL resource availability and maintaining high network resource utilization efficiency.
3Loss of time
If the UE selects 2-step RA procedure to reduce latency, then the RA procedure duration is reduced, but the complexity of resource management increases
Solution Approach 1:
The patent manages the complexity of 2-step RA resource selection through dynamic adaptation. The UE uses clear decision criteria (checking UL resource availability and buffer status) to determine when to use 2-step RA, which simplifies the overall resource management despite the reduced procedure duration. The dynamic selection based on well-defined conditions prevents arbitrary complexity while achieving lower latency.
Data Source
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AI summary
A wireless communication method and a User Equipment (UE) for performing Random Access (RA) operations are provided. The communication method is performed by the UE and includes receiving a Radio Resource Control (RRC) message that indicates a first Physical Uplink Shared Channel (PUSCH) resource for Message A (MSGA) payload transmission; triggering a Scheduling Request (SR) procedure; initiating an RA procedure after receiving the RRC message, in a case that no Physical Uplink Control Channel (PUCCH) resource is configured for the SR procedure; determining that a second PUSCH resource is available while the RA procedure is ongoing, the second PUSCH resource not being indicated by the RRC message as the first PUSCH resource; and stopping the ongoing RA procedure in a case that a Medium Access Control (MAC) Protocol Data Unit (PDU) including a Buffer Status Reporting (BSR) MAC Control Element (CE) is transmitted on the second PUSCH resource or the second PUSCH resource can accommodate all pending data for transmission.