Adaptive DRX Timer Control for UE Buffer and Latency Alignment
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Solution Overview
Problem
The challenge in wireless communication systems is to efficiently manage Discontinuous Reception (DRX) timers to reduce latency and align UE and network operations, particularly in scenarios with varying data buffer sizes and latency-sensitive applications.
Innovation Solution
A method and apparatus for a user equipment (UE) that starts or restarts a DRX timer based on the buffer size of transmitted MAC PDUs, adjusting the DRX timer value depending on whether the buffer size is above or below a threshold, and monitors the Physical Downlink Control Channel (PDCCH) during the timer's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the DRX timer is used to reduce power consumption by putting the UE in sleep mode, then energy efficiency is improved, but latency increases because the UE may miss downlink data transmissions
Solution Approach 1:
The patent applies dynamics by making the DRX timer value adaptive rather than fixed. The timer dynamically adjusts its duration based on real-time buffer status feedback from the UE to the network. When the buffer is empty or near-empty, a longer DRX timer extends sleep periods for power savings. When the buffer contains data, the timer shortens or resets to ensure the UE remains awake to receive transmissions, thus balancing power consumption and latency requirements dynamically
Solution Approach 2:
The patent implements feedback mechanisms where the UE reports buffer status information (BSI) to the network, and the network uses this feedback to adjust scheduling decisions. The buffer status feedback creates a closed-loop control system that enables the network to optimize DRX timer values based on actual data conditions, preventing both excessive power consumption (by avoiding unnecessarily long sleep periods when data is present) and excessive latency (by extending sleep periods when the buffer is empty)
2Use of energy by moving object
If the DRX timer value is extended to allow longer sleep periods for power saving, then energy efficiency is improved, but the risk of misalignment between UE and network operations increases
Solution Approach 1:
The patent uses buffer status feedback as a synchronization mechanism. The UE continuously monitors its buffer and provides feedback to the network about data presence. This feedback loop ensures that both the UE and network maintain a consistent understanding of the data state, preventing misalignment even when DRX timer values are extended. The network uses this feedback to coordinate its transmissions with the UE's wake-up schedule
Solution Approach 2:
The patent applies preliminary action by having the UE proactively report buffer status before the network needs to transmit data. This advance information allows the network to prepare scheduling decisions in advance, ensuring that when the UE wakes up from sleep mode, the network is ready to transmit if needed, thus maintaining synchronization without requiring the UE to remain awake continuously
3Loss of time
If the DRX timer is shortened to reduce latency and ensure timely data reception, then latency is reduced, but power consumption increases due to more frequent wake-ups
Solution Approach 1:
The patent applies dynamics by making the DRX timer value adaptive rather than fixed. The timer dynamically adjusts its duration based on real-time buffer status feedback from the UE to the network. When the buffer is empty or near-empty, a longer DRX timer extends sleep periods for power savings. When the buffer contains data, the timer shortens or resets to ensure the UE remains awake to receive transmissions, thus balancing power consumption and latency requirements dynamically
Solution Approach 2:
The patent changes the parameter of DRX timer duration based on buffer status conditions. By varying this critical parameter according to actual data presence, the system optimizes the trade-off between power consumption and latency. The parameter change is triggered by buffer status feedback, allowing the system to adapt to changing traffic conditions and achieve optimal performance for each specific scenario
Data Source
AI summary
The present disclosure relates to a method of transmitting a Medium Access Control (MAC) protocol data unit (PDU) by a user equipment (UE) in a wireless communication system. Especially, the method includes the steps of based on a first Medium Access Control (MAC) control element (CE) being triggered, transmitting, on a data uplink (UL) grant to a network, information indicating an amount of the first MAC CE to be transmitted; receiving a control UL grant from the network; constructing a MAC protocol data unit (PDU) including the first MAC CE; and transmitting the MAC PDU using the control UL grant.