LBT Failure Detection in Dormant Cells and DRX Cycles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication networks, especially in dormant mode or discontinuous reception (DRX) cycles, there is a challenge in effectively detecting listen-before-talk (LBT) failures and channel occupancy, leading to potential delays in reactivating cells and inefficient power management due to lack of real-time channel availability information.
Innovation Solution
Implementing mechanisms for user equipment (UE) to perform LBT failure detection and channel occupancy measurements while in dormant mode or during inactive DRX cycles, allowing base stations to better assess channel conditions and balance power savings with low activation latency by configuring UE to perform UL and DL LBT measurements, RSSI/CO measurements, and reporting these findings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If UE operates in dormant mode or inactive DRX to save power, then power consumption is reduced, but LBT failure detection capability is lost
Solution Approach 1:
The network configures the UE to perform LBT failure detection and channel occupancy measurements in advance while in dormant mode or during inactive DRX periods. This preliminary action ensures that channel conditions are already assessed when activation is needed, eliminating detection gaps without requiring continuous active monitoring.
Solution Approach 2:
The UE provides feedback reports containing LBT failure detection results and channel occupancy information to the network even while in dormant mode. This feedback mechanism maintains detection capability during low-power states by selectively activating measurement functions and reporting results when needed.
2Reliability
If UE continuously monitors channel to detect LBT failures, then detection reliability is improved, but power consumption increases
Solution Approach 1:
Instead of continuous monitoring, the UE performs LBT failure detection periodically or at specific intervals configured by the network. This periodic action maintains detection reliability by sampling channel conditions at meaningful intervals while allowing the UE to remain in low-power states between measurements.
Solution Approach 2:
The UE performs partial monitoring by focusing only on essential LBT failure detection functions during dormant periods rather than full channel monitoring. This selective partial action maintains sufficient detection capability for reliability while minimizing power consumption by avoiding unnecessary comprehensive monitoring.
3Loss of time
If UE activates cell immediately when needed, then activation latency is reduced, but channel conditions may be unfavorable
Solution Approach 1:
The UE performs preliminary LBT failure detection and channel occupancy measurements while in dormant mode before activation is required. This advance preparation ensures that when the cell needs to be activated, the UE already has current channel condition information, enabling immediate activation with knowledge of favorable conditions.
Solution Approach 2:
The UE autonomously assesses channel conditions and provides this information to the network without requiring network-initiated measurements. This self-service capability allows the UE to independently determine channel availability, enabling faster activation decisions based on real-time channel state.
4Loss of information
If UE performs comprehensive channel measurements, then channel awareness is improved, but processing complexity increases
Solution Approach 1:
The patent extracts only the essential measurement functions needed for LBT failure detection and channel occupancy assessment from the full set of possible channel measurements. By taking out only the critical measurement components and discarding unnecessary comprehensive monitoring during dormant periods, the system maintains adequate channel awareness while reducing processing complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Wireless communications systems and methods related to communications in a network are provided. A UE receives a listen-before-talk (LBT) failure detection configuration associated with at least one of a dormant mode or a discontinuous reception (DRX) cycle in a first cell of a wireless communication network. The UE performs, based on the LBT failure detection configuration, an LBT failure detection in the first cell while operating in the dormant mode for the first cell or during an inactive DRX configured-on duration of the DRX cycle. The UE transmits an LBT failure detection report based on the LBT failure detection.