LBT CCA Timing Configuration for Reduced Latency
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in channel access procedures, particularly in shared frequency bands, where the random backoff period in listen-before-talk (LBT) can lead to increased latency and interference due to the uncertainty in channel access duration, affecting network efficiency and power consumption.
Innovation Solution
The implementation of an upgraded clear channel assessment (CCA) timing configuration, where the user equipment (UE) performs CCA based on a non-random counter value indicated by the base station (BS), allowing for a shorter and predictable CCA duration, thereby reducing the time gap between scheduled communications and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If random backoff period is used in LBT, then channel access fairness is improved, but latency and uncertainty in channel access duration increase
Solution Approach 1:
The patent applies dynamics by making the CCA timing configuration adjustable between different modes (first configuration with random backoff for fairness, second configuration with fixed timing for low latency). The system dynamically selects the appropriate configuration based on service requirements, allowing transition between fairness-oriented and latency-oriented channel access behaviors.
Solution Approach 2:
The patent changes the timing parameters of CCA from random (first configuration) to fixed/deterministic (second configuration). By modifying the backoff parameter from a random variable to a fixed value, the system reduces uncertainty and latency while maintaining the ability to switch configurations based on service type.
2Reliability
If random backoff period is used in LBT, then channel access fairness is improved, but network efficiency deteriorates
Solution Approach 1:
The system dynamically adapts the CCA timing configuration based on service requirements. For latency-sensitive services, it switches to the second configuration with fixed timing, improving network efficiency and productivity by eliminating random delays while maintaining fairness for other services through the first configuration.
Solution Approach 2:
The patent modifies the CCA timing parameters from random to fixed, changing the statistical properties of channel access. This parameter change reduces variability in access time, allowing more predictable scheduling and improving overall network throughput and efficiency.
3Reliability
If CCA timing configuration is extended, then channel access reliability is improved, but time gap between scheduled communications increases
Solution Approach 1:
The patent implements dynamic switching between two CCA timing configurations. The first configuration provides extended sensing for reliability, while the second provides shortened sensing for low latency. The system dynamically selects the appropriate configuration based on service type, achieving both reliability and low time gap through adaptive behavior.
Solution Approach 2:
The patent changes the CCA duration parameter from extended (first configuration) to shortened (second configuration), allowing the system to reduce the time gap between scheduling and communication when low latency is required, while maintaining reliability through selective use of the extended configuration.
Data Source
AI summary
A method of wireless communication performed by a user equipment (UE) may include: receiving, from a base station (BS), first downlink control information (DCI) scheduling an uplink (UL) communication; receiving, from the BS, a request to perform a clear channel assessment (CCA) associated with a first CCA timing configuration; performing, based on an indication to change to a second CCA timing configuration different from the first CCA timing configuration, the CCA based on the second CCA timing configuration; and transmitting, to the BS based on the CCA, the UL communication.