Flexible DRX Cycle Adjustment Based on Timing Alignment Timer
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Solution Overview
Problem
The current RRC connected mode Discontinuous Reception (DRX) scheme in E-UTRAN does not efficiently account for the readiness of scheduling combined with the likelihood of scheduling, leading to suboptimal power savings and scheduling efficiency.
Innovation Solution
A flexible DRX scheme that dynamically adjusts between shorter and longer DRX cycles based on the timing alignment timer (TAT) status, applying a shorter cycle when scheduling likelihood is high and a longer cycle when it is low, to synchronize UE and eNB operations without additional signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a fixed DRX cycle is used in RRC connected mode, then the UE can achieve power savings, but the scheduling efficiency and responsiveness to scheduling opportunities are reduced
Solution Approach 1:
The patent applies dynamics by making the DRX cycle length adjustable based on the timing alignment timer state. The UE dynamically switches between shorter and longer DRX cycles according to whether the timing alignment timer is running, allowing the system to adapt to changing scheduling conditions rather than using a fixed cycle length throughout.
Solution Approach 2:
The patent changes the DRX cycle parameter based on the timing alignment timer state. When the timer is running, a shorter DRX cycle is applied; when not running, a longer DRX cycle is applied. This parameter adjustment resolves the contradiction by optimizing both power consumption and scheduling efficiency under different operational conditions.
2Speed
If a shorter DRX cycle is applied continuously, then scheduling responsiveness is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic action by alternating between shorter and longer DRX cycles based on the timing alignment timer state. The UE monitors the timer periodically and adjusts the DRX cycle length accordingly, applying shorter cycles only when scheduling is likely (timer running) and longer cycles when scheduling is unlikely (timer not running), thus achieving responsive scheduling only when necessary.
Solution Approach 2:
The system dynamically adjusts the DRX cycle length based on real-time timer state, transitioning between shorter and longer cycles as needed. This dynamic adaptation allows the UE to maintain high scheduling responsiveness when the timer is running while conserving power when the timer is not running, resolving the contradiction between speed and energy consumption.
3Use of energy by moving object
If a longer DRX cycle is applied continuously, then power savings are maximized, but scheduling latency increases
Solution Approach 1:
The patent changes the DRX cycle parameter based on the timing alignment timer state to resolve the contradiction. When the timer is running, indicating high scheduling likelihood, a shorter DRX cycle is applied to reduce latency. When the timer is not running, a longer DRX cycle is applied to maximize power savings. This conditional parameter adjustment optimizes both power consumption and latency.
Solution Approach 2:
The system periodically monitors the timing alignment timer and adjusts the DRX cycle length accordingly. This periodic adjustment ensures that shorter cycles (low latency) are applied only when scheduling is likely, while longer cycles (high power savings) are applied when scheduling is unlikely, thus resolving the contradiction between power consumption and latency.
4Reliability
If the UE monitors downlink channels continuously, then scheduling opportunities are not missed, but power consumption increases
Solution Approach 1:
The patent applies dynamics by adjusting the downlink monitoring frequency based on the timing alignment timer state. When the timer is running, the UE monitors downlink channels more frequently (shorter DRX cycle) to ensure reliable detection of scheduling opportunities. When the timer is not running, the UE monitors less frequently (longer DRX cycle) to reduce power consumption, accepting lower monitoring intensity when scheduling is unlikely.
Solution Approach 2:
The patent changes the downlink monitoring parameter (DRX cycle length) based on the timer state to resolve the contradiction. The monitoring frequency is adjusted dynamically: higher when the timer is running to ensure reliable scheduling detection, and lower when the timer is not running to save power. This parameter adjustment optimizes both reliability and power consumption.
Data Source
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AI summary
One embodiment is directed to a method for applying a flexible discontinuous reception scheme. The method includes receiving, at a user equipment, a timing alignment timer as input. The method then includes determining a type of discontinuous reception cycle to apply based on a likelihood of scheduling of the user equipment, and applying the determined type of discontinuous reception cycle.