C-DRX Timer Selection via Logical Channel Mapping
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Solution Overview
Problem
In 5G NR networks, there is a need to reduce power consumption during network access mode in RRC_CONNECTED mode to enhance operational times of wireless communication devices, while ensuring reliable reception by properly timing the implementation of connected-mode discontinuous reception (C-DRX) to avoid erroneous reception events that impact power consumption and communication performance.
Innovation Solution
The selection of a C-DRX timer value is based on whether logical channels (LCHs) are allowed or mapped to an uplink grant, using configured mapping restrictions and ranking rules to determine the appropriate timer setting for power-efficient operation, allowing the UE to switch between active and quiescent modes effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If C-DRX timer value is extended to improve power saving, then power consumption is reduced, but reception reliability deteriorates due to erroneous reception events
Solution Approach 1:
The patent implements dynamic C-DRX timer selection by configuring multiple timer values (first C-DRX timer value and second C-DRX timer value) and dynamically selecting between them based on LCH mapping conditions. The MAC entity determines which timer value to apply based on whether specific LCHs are mapped to the uplink grant, allowing the system to adapt the DRX behavior to current traffic conditions rather than using a fixed timer value.
Solution Approach 2:
The patent changes the C-DRX timer parameter based on LCH mapping restrictions. When LCHs with specific mapping restrictions are mapped to the uplink grant, the first C-DRX timer value is used; otherwise, the second C-DRX timer value is used. This parameter change mechanism allows optimization of both power consumption and reception reliability by selecting appropriate timer values based on the actual logical channel conditions.
2Reliability
If C-DRX timer value is extended to allow UE to remain in active mode longer, then reception reliability is improved, but power consumption increases
Solution Approach 1:
The system dynamically adjusts the C-DRX timer value based on real-time LCH mapping conditions. When traffic conditions allow (specific LCHs are mapped), a shorter timer value is used to enable faster transition to sleep mode. When different traffic conditions exist (different LCH mapping), a longer timer value is used to ensure reliable reception. This dynamic adjustment resolves the contradiction by making the timer value adaptive rather than fixed.
Solution Approach 2:
The patent implements parameter changes by configuring at least two different C-DRX timer values and selecting between them based on LCH mapping restrictions. The MAC entity monitors the mapping conditions and switches between timer values accordingly, allowing the system to optimize the balance between reception reliability and power consumption based on actual traffic requirements.
3Adaptability or versatility
If multiple C-DRX timer values are configured based on LCH mapping, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent segments the C-DRX configuration by associating different timer values with different LCH mapping conditions. Instead of using a single unified timer value, the system divides the configuration into multiple segments (first C-DRX timer value for specific LCH mapping conditions, second C-DRX timer value for other conditions). This segmentation allows fine-grained control and high adaptability while maintaining clear, condition-based selection logic.
Solution Approach 2:
The system implements feedback mechanisms where the MAC entity continuously monitors LCH mapping conditions and uses this feedback to determine which C-DRX timer value to apply. The network configures the multiple timer values and LCH mapping restrictions, and the UE provides feedback through its selection behavior, creating a closed-loop system that adapts to changing traffic conditions while managing complexity through structured decision logic.
Data Source
AI summary
A method and apparatus are provided for, in aspects, receiving, at a User Equipment (UE), a configuration relating to a logical channel (LCH) from a Base Station (BS); receiving, at the UE, an uplink grant for an uplink data; identifying a subset of the LCH mappable to the uplink grant based on the at least a part of the configuration; determining, at the UE, a connected-mode discontinuous reception (C-DRX) setting to be applied for an uplink transmission associated with the uplink grant based on the identified subset of the LCH; and controlling a quiescent state of the UE based on the C-DRX setting, wherein, in aspects, mappable may refer to allowed to be mapped or actually mapped. When LCHs of the subset are associated with different C-DRX settings, rule-based C-DRX selection can be used.