LTE DRX Configuration via MAC Control Element
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Solution Overview
Problem
Current Long Term Evolution (LTE) systems face challenges in efficiently configuring and managing Discontinuous Reception (DRX) periods for user equipment (UE) in the LTE_ACTIVE state, particularly in handling battery savings, signaling efficiency, and handling missed handover opportunities.
Innovation Solution
The method involves signaling DRX values and timing margins within a modified MAC-PDU header, allowing direct transition to a long DRX period without RRC reconfiguration, leveraging application traffic characteristics, and adjusting measurement cycles based on signal quality to improve battery life and measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the eNB uses RRC reconfiguration message to activate/deactivate short DRX and then issues go-to-sleep MAC control element, then the UE can transition between short and long DRX cycles, but the signaling overhead increases and the process becomes more complex
Solution Approach 1:
The patent combines the DRX configuration and activation control into a single MAC Control Element. Instead of using separate RRC reconfiguration messages for DRX setup and MAC control elements for activation, the invention integrates both functions into one MAC CE that contains both the DRX configuration parameters and the activation command, thereby reducing signaling overhead and simplifying the control process.
Solution Approach 2:
The MAC Control Element is designed to serve multiple functions simultaneously: it configures DRX parameters, activates DRX mode, and can transition between short and long DRX cycles. This multi-functional approach eliminates the need for separate signaling messages for each DRX control operation, directly addressing the complexity issue while maintaining full adaptability.
2Adaptability or versatility
If the eNB frequently reconfigures DRX parameters using RRC messages, then the DRX can be adapted to traffic patterns, but the network resource consumption and signaling overhead increase
Solution Approach 1:
The patent implements dynamic DRX adjustment by allowing the eNB to send MAC Control Elements that can activate, deactivate, or reconfigure DRX parameters on-the-fly based on current traffic conditions. This dynamic approach using lightweight MAC layer signaling instead of heavy RRC messages enables flexible traffic adaptation while minimizing network resource consumption and energy waste.
3Speed
If the UE stays in short DRX cycle, then the network can quickly respond to traffic changes, but the battery consumption increases compared to long DRX
Solution Approach 1:
The system dynamically switches between short and long DRX cycles based on traffic activity. When traffic is active, the UE operates in short DRX for fast response. When traffic becomes inactive, the eNB sends a MAC Control Element to transition the UE to long DRX for battery saving. This dynamic state transition allows the system to optimize between response speed and energy consumption in real-time.
Solution Approach 2:
The patent uses periodic DRX cycles with configurable durations. The UE alternates between listening periods (on-duration) and sleeping periods according to DRX cycles. By adjusting the cycle length and using MAC control to switch between short and long cycles, the system achieves periodic monitoring that balances network responsiveness with battery conservation.
4Productivity
If the eNB uses MAC Control Element for DRX activation, then the signaling is more efficient, but the ability to reconfigure DRX parameters is limited compared to RRC messages
Solution Approach 1:
The patent merges DRX configuration parameters and activation control into a single MAC Control Element. The MAC CE includes fields for DRX configuration (such as drx-Offset, drx-Period, onDuration) along with activation bits. This combination maintains the signaling efficiency of MAC layer while preserving the reconfiguration capability traditionally provided by RRC messages.
Solution Approach 2:
The MAC Control Element is designed to carry configurable DRX parameters that can be modified dynamically. By embedding parameter change capabilities within the MAC CE structure, the system allows reconfiguration of DRX characteristics (period, offset, duration) using efficient MAC layer signaling instead of requiring RRC message exchanges, thus maintaining both efficiency and adaptability.
Data Source
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AI summary
A method for configuring a discontinuous reception 'DRX' period for a user equipment from an evolved Node B 'eNB' comprising: determining whether a precondition has been met, wherein the precondition is at least one of a low traffic volume for the user equipment, a lack of uplink and downlink transmissions for the user equipment, and a likely transition of the user equipment to another cell; when the precondition has been met, sending a MAC control element for a long DRX period; and when the precondition has been not met, maintaining a short DRX period.