DRX Cycle Entry via End of Data Indication in LTE UEs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in LTE, there is a need to optimize the Discontinuous Reception (DRX) operation to reduce power consumption and improve efficiency, especially for low-complexity User Equipment (UE) like Category 0 devices, which currently face inefficiencies in transitioning from active to inactive states, leading to increased battery usage and potential desynchronization with the network.
Innovation Solution
The UE initiates a DRX cycle immediately after transmitting the last MAC PDU to the eNB, using an End of Data Indication and leveraging DRX timers, allowing it to enter a power-saving state without waiting for the drx-InactivityTimer to expire, thus reducing unnecessary PDCCH monitoring and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the UE waits for the drx-InactivityTimer to expire before entering DRX cycle, then the network synchronization is maintained, but the power consumption increases due to unnecessary PDCCH monitoring
Solution Approach 1:
The UE performs preliminary actions by transmitting an End of Data Indication before the drx-InactivityTimer expires, signaling to the network that no further data transmission is needed. This allows the UE to proactively enter the DRX state immediately after data transmission completes, rather than waiting passively for the timer to expire, thereby reducing unnecessary PDCCH monitoring and power consumption while maintaining network synchronization through the indication mechanism
Solution Approach 2:
The UE provides feedback to the network by transmitting the End of Data Indication, which informs the network about the completion of data transmission. This feedback mechanism enables the network to be aware of the UE's data transmission status and allows the UE to transition to DRX state based on this feedback, resolving the contradiction between early DRX entry and network synchronization
2Use of energy by moving object
If the UE enters DRX cycle immediately after transmitting the last MAC PDU, then power consumption is reduced, but the network may not be aware of the UE's inactive state
Solution Approach 1:
The UE performs the preliminary action of transmitting the End of Data Indication to the network before entering the DRX state. This indication serves as advance notice to the network that the UE has completed data transmission and will transition to an inactive state, allowing the UE to enter DRX immediately after data transmission while keeping the network informed, thus resolving the information asymmetry issue
Solution Approach 2:
The UE autonomously determines when to enter the DRX state by monitoring its own data transmission status and using the End of Data Indication mechanism. This self-service approach allows the UE to independently manage its power state transitions based on its own data buffer status, entering DRX as soon as it determines no more data needs to be transmitted, while the network receives the indication and can accordingly adjust its expectations
Data Source
AI summary
The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing DRX operation in wireless communication system, the method comprising: generating a MAC PDU including an indicator indicating the MAC PDU is a last MAC PDU to be transmitted to an eNB if the generated MAC PDU is a last MAC PDU to be transmitted to the eNB; transmitting the MAC PDU including the indicator; and starting using a DRX cycle right after the UE considers that the transmission of MAC PDU is successful.