RRC Scheduling Requests with LCG-Aware PUCCH Mapping for Low-Latency Uplink
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently and flexibly managing uplink scheduling requests (SR) and buffer status reports (BSR) due to limited information provided by one-bit SRs and strict BSR triggering rules, leading to inefficiencies and increased latency in handling diverse services like eMBB and URLLC.
Innovation Solution
Enhancements to SR and BSR mechanisms in 5G NR systems, including extended SR information bits for detailed LCG data availability and priority, grant-free BSR transmissions, and flexible BSR triggering, along with dynamic resource allocation by the gNB scheduler to support various services and reduce latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If one-bit scheduling request (SR) is used, then device complexity is reduced, but information transmission completeness deteriorates
Solution Approach 1:
The patent segments the scheduling request information by dividing it into multiple priority levels (e.g., high priority, medium priority, low priority). Each priority level corresponds to different logical channel groups (LCGs), allowing the system to transmit more comprehensive information about data availability across different LCGs while maintaining a relatively simple SR structure. This segmentation enables the network to understand which specific LCGs have data pending without requiring a single-bit SR to carry all information.
Solution Approach 2:
The patent introduces a priority dimension to the traditional one-bit SR mechanism. Instead of simply indicating whether data is available or not, the SR now conveys priority information that maps to different LCGs. This dimensional expansion allows the system to transmit more information (which LCGs have data and at what priority) without significantly increasing the complexity of the SR mechanism itself.
2Productivity
If strict BSR triggering rules are applied, then resource allocation efficiency is improved, but scheduling flexibility deteriorates
Solution Approach 1:
The patent implements dynamic BSR triggering rules that can adapt to different service requirements and network conditions. Instead of applying rigid, uniform triggering conditions, the system dynamically adjusts BSR triggering based on factors such as service type (eMBB, URLLC), buffer status, and network load. This dynamic approach maintains resource allocation efficiency by avoiding unnecessary BSR transmissions while providing the flexibility to trigger BSRs when specific conditions are met, thereby supporting diverse service requirements.
Solution Approach 2:
The patent changes the parameters governing BSR triggering based on service type and network conditions. For example, different threshold values, timing parameters, and triggering conditions are applied depending on whether the service is eMBB or URLLC. This parameter adjustment allows the system to maintain efficient resource allocation by tuning the triggering sensitivity appropriately for each service type, while simultaneously achieving the flexibility needed to handle diverse communication requirements.
3Measurement precision
If detailed LCG information is transmitted, then scheduling accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent makes the enhanced SR mechanism with detailed LCG information universally applicable across different service types and scenarios. By designing a unified framework where the same SR structure can convey priority and LCG information for both eMBB and URLLC services, the system achieves scheduling accuracy without requiring separate signaling mechanisms for different services. This multi-functionality reduces overall signaling overhead compared to having service-specific detailed reporting mechanisms.
Solution Approach 2:
The patent uses existing SR and BSR structures as templates, copying and adapting them for enhanced functionality rather than creating entirely new signaling mechanisms. The enhanced SR builds upon the existing one-bit SR format by adding priority indication, leveraging the established signaling framework. This approach reduces signaling overhead by reusing proven structures while incrementally adding the necessary information for accurate scheduling, rather than implementing completely new detailed reporting protocols.
4Loss of time
If grant-free BSR transmissions are implemented, then latency is reduced, but resource management complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring grant-free BSR transmission resources during the connection setup or reconfiguration phases. The network allocates dedicated uplink resources for grant-free BSR transmissions in advance, so that when data becomes available and a BSR needs to be transmitted, the UE can immediately use the pre-allocated resources without waiting for dynamic grant allocation. This preliminary resource allocation reduces BSR transmission latency while managing complexity by establishing resource rules in advance rather than making real-time allocation decisions.
Data Source
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AI summary
A user equipment (UE) is described. The UE includes receiving circuitry configured to receive, from a base station apparatus, a radio resource control (RRC) message(s) comprising one or more scheduling request (SR) configurations. Each SR configuration is associated with one or more PUCCH resources. The SR configuration is corresponding to any one or more of the following: one or more logical channels (LCH), one or more logical channel groups (LCG), one or more priority, one or more numerology, one or more services, and/or one or more bandwidth part (BWP).