UE DRX State Handling for Downlink Data Transmission Delay
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Solution Overview
Problem
In wireless communications, particularly in UMTS systems, user equipment (UE) experiences delayed downlink data transmission when in a long DRX state, leading to potential idle states and energy inefficiencies due to the fallback to PRACH access, which does not interrupt the DRX timer, causing base stations to delay sending data.
Innovation Solution
A method where the user terminal ignores the fallback to PRACH indication if in a DRX state and continues initiating access on the E-DCH until a specific condition is met, such as reaching a maximum MAC layer random access cycle or receiving a positive acknowledgement frame, allowing the UE to exit the DRX state and enter continuous reception, thereby preventing delayed downlink data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE falls back to PRACH access when receiving fallback indication, then the common E-DCH congestion is alleviated, but the downlink data transmission is delayed because the UE may be in DRX off state
Solution Approach 1:
The UE proactively exits the DRX state and enters continuous reception state before the downlink data transmission occurs, ensuring that the UE is ready to receive data immediately when the base station sends it, thereby eliminating transmission delays
Solution Approach 2:
The UE dynamically transitions from DRX state to continuous reception state based on the fallback indication, adapting its reception behavior to ensure reliable and timely downlink data transmission
2Use of energy by moving object
If the UE stays in DRX state to save energy, then energy consumption is reduced, but the downlink data transmission is delayed
Solution Approach 1:
The UE exits the DRX state in advance upon receiving the fallback indication, preparing itself for immediate downlink data reception and avoiding any transmission delays while managing energy consumption efficiently
Solution Approach 2:
The UE changes its reception state parameter from DRX mode to continuous reception mode based on the fallback indication, optimizing the balance between energy consumption and transmission timing
Data Source
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AI summary
Embodiments of the present invention provide a method for processing channel access and an apparatus thereof. The method includes: receiving a fallback to physical random access channel (PRACH) indication sent by a base station; and initiating access on a common enhanced dedicated channel common (E-DCH). At or before the receiving a fallback to physical random access channel (PRACH) indication sent by a base station, the method further includes: determining that a current state is a discontinuous reception (DRX) state or a timer that sets time for entering the DRX state is in a running state; and determining that fallback to PRACH is supported and an enhanced DRX capability is possessed; where the determining that a current state is a discontinuous reception (DRX) state includes: determining that the current state is a first DRX state of enhanced discontinuous reception (DRX) or a second DRX state of enhanced DRX. In the embodiments of the present invention, a fallback to PRACH indication is not executed, so as to prevent a user terminal from being in a DRX off state when a base station sends downlink data to the UE, thereby preventing the base station from delaying sending the downlink data to the UE.