Access Point CCA Threshold Adjustment for WLAN Interference Control
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Solution Overview
Problem
In wireless local area networks (WLANs), increasing the clear channel assessment (CCA) threshold to improve throughput can instead reduce system throughput due to increased interference from concurrent links in dense deployment environments.
Innovation Solution
A method is introduced where an access point determines a concurrent group of stations with the highest received signal strengths, adjusts the CCA threshold for these stations, and coordinates channel contention within a specific time frame, while other stations maintain a lower CCA threshold, thereby controlling the number of concurrent links and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the CCA threshold is increased to improve data throughput rate, then the possibility of link transmission increases, but the system throughput is reduced due to increased interference from concurrent links
Solution Approach 1:
The patent applies local quality by differentiating CCA threshold settings for different station groups. Concurrent STAs in the same time slot use a first CCA threshold, while non-concurrent STAs use a second CCA threshold. This localized differentiation allows the system to optimize throughput for specific links without causing system-wide interference, resolving the contradiction between improving data throughput rate and reducing interference.
Solution Approach 2:
The patent segments the STA population into concurrent STAs and non-concurrent STAs based on their transmission timing. By dividing the system into these distinct groups with different CCA threshold settings, the patent enables controlled concurrent transmissions while preventing excessive interference, thus improving overall system throughput without sacrificing individual link transmission probability.
2Reliability
If the CCA threshold is increased to increase possibility of link transmission, then link transmission success rate improves, but the number of concurrent links increases causing reduced system throughput
Solution Approach 1:
The patent implements local quality by assigning different CCA threshold values to different STA groups based on their concurrent status. Concurrent STAs benefit from a higher first CCA threshold that improves their link transmission success rate, while non-concurrent STAs use a lower second CCA threshold that limits the total number of concurrent links, thereby maintaining system throughput.
Solution Approach 2:
The patent changes the CCA threshold parameter dynamically based on STA concurrency status. By adjusting the CCA threshold from a single system-wide value to two distinct values (first CCA threshold for concurrent STAs, second CCA threshold for non-concurrent STAs), the patent simultaneously improves link transmission reliability for active links and controls the overall number of concurrent links to maintain system throughput.
Data Source
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AI summary
Embodiments of the present invention provide a method for adjusting a clear channel assessment CCA threshold, and a device. The method includes: determining, by an AP from all STAs associated with the AP, a concurrent STA joining a concurrent group, and generating concurrent group information of the concurrent group; and sending the concurrent group information to another AP in a system other than the AP, so that a BSS to which the another AP belongs determines, according to the concurrent group information, to join the concurrent group, to eventually form the concurrent group. All concurrent STAs that are associated with the AP and that join the concurrent group perform channel contention within a concurrent time by using an increased target CCA threshold, to increase a possibility that the concurrent STAs send data, so that a system throughput is improved. All STAs out of the concurrent group that are associated with the AP and a non-concurrent STA, which is associated with the AP, in the concurrent group perform channel contention by using a relatively low normal CCA threshold. In this way, a quantity of concurrent links can be controlled by controlling a quantity of BSSs in the concurrent group. Therefore, interference between the concurrent links is reduced, and the system throughput is further improved.