Network Element Channel Access Method for High Unlicensed Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to design a high-frequency system Listen Before Talk (LBT) mechanism that is compatible with low-frequency system LBT mechanisms, particularly for high unlicensed frequency bands above 6 GHz, where existing LBT mechanisms from low-frequency bands are not effective due to differences in interference patterns and channel access requirements.
Innovation Solution
The proposed solution involves a channel access method that uses a combination of Cat-4 and Cat-2 LBT mechanisms, where Cat-4 LBT is performed for channel preemption followed by Cat-2 LBT for subsequent TTIs within a maximum channel occupancy time (MCOT), and a frame structure that includes LBT gaps for channel state detection, ensuring efficient channel access and data transmission in high unlicensed frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LBT mechanism from low-frequency bands is used for high unlicensed frequency bands, then channel access can be established, but the mechanism is not effective due to differences in interference patterns and channel access requirements
Solution Approach 1:
The patent applies parameter changes by modifying LBT mechanism parameters specifically for high unlicensed frequency bands. It introduces frequency band-specific parameters including contention window sizes, backoff counters, and energy detection thresholds that are optimized for high-frequency characteristics, making the LBT mechanism adaptable while maintaining effectiveness
Solution Approach 2:
The patent segments the LBT mechanism into band-specific implementations. It divides the unified LBT approach into separate parameter sets for different frequency bands (e.g., 5 GHz, 6 GHz, 7 GHz), allowing each band to have optimized parameters tailored to its interference patterns and channel access requirements
2Productivity
If Cat-4 LBT is performed for channel preemption followed by Cat-2 LBT for subsequent TTIs, then channel access efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies dynamics by implementing a dynamic LBT mechanism that transitions between Cat-4 and Cat-2 modes. The system dynamically selects the appropriate LBT category based on channel conditions, transmission timing, and occupancy status, optimizing channel access efficiency while managing device complexity through adaptive behavior
Solution Approach 2:
The patent applies preliminary action by performing Cat-4 LBT with full backoff procedure before channel preemption to ensure fair channel access. After successful preemption, the system then uses simpler Cat-2 LBT for subsequent transmissions within the same occupancy period, reducing complexity for repeated access attempts
3Productivity
If directional signal transmission is used, then system capacity is improved, but measurement precision for channel state detection becomes more difficult
Solution Approach 1:
The patent applies local quality by implementing directional energy detection that focuses measurement efforts in specific spatial directions. Instead of omnidirectional detection, the system performs localized channel state measurements along transmission beams, improving measurement precision for directional signals while maintaining enhanced system capacity
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
This application provides a channel access method, including: performing, by a network element, random backoff LBT for channel preemption, and after the preemption succeeds, performing, signal transmission in the first transmission time interval TTI within a maximum channel occupancy time MCOT; and performing, by the network element before another at least one TTI within the maximum channel occupancy time MCOT, nonrandom backoff LBT for channel preemption, to ensure coexistence and performance of systems when an LBT requirement of a high unlicensed frequency band is met.