Dynamic CCAT Adjustment for Wireless Interference Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless communications networks face interference issues due to static Clear Channel Assessment Thresholds (CCAT) in IEEE 802.11 WLANs, limiting simultaneous transmissions and network performance, while adaptive CCATs can increase throughput but also increase interference, leading to packet loss and reduced performance.

Innovation Solution

Nodes in the network adjust transmission parameters based on timing conditions of interference relative to the reception of transmission signals, identified through patterns and decoding errors, to optimize spatial reuse and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a static Clear Channel Assessment Threshold (CCAT) is used, then interference is reduced and transmission reliability is improved, but the number of simultaneous transmissions is limited and network throughput decreases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidnetwork throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by transitioning from a static CCAT to a dynamic CCAT that adapts based on received signal strength measurements. The receiving node measures the RSSI of received transmissions and uses this information to dynamically adjust the CCAT value, allowing the system to optimize between reliability and throughput based on current channel conditions rather than being constrained by a fixed threshold.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the CCAT parameter based on measured RSSI values. The system changes the threshold parameter dynamically according to channel conditions, enabling the network to adapt the sensitivity of channel assessment to match actual interference levels, thereby increasing simultaneous transmissions while maintaining acceptable reliability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If an adaptive Clear Channel Assessment Threshold (CCAT) is used, then the number of simultaneous transmissions and network throughput are increased, but interference levels increase and packet loss occurs

Engineering Contradiction:
Improvenetwork throughputVSAvoidinterference levels
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies feedback by having the receiving node measure the RSSI of received transmissions and use this feedback information to adjust the CCAT. The system continuously monitors channel conditions through RSSI measurements and adjusts the threshold accordingly, creating a closed-loop control mechanism that prevents excessive interference while maximizing throughput.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements self-service by enabling nodes to autonomously adjust their own CCAT values based on local RSSI measurements without requiring centralized control. Each receiving node independently measures the channel conditions and adapts its threshold, allowing the network to self-regulate interference levels while maintaining high throughput.

Inventive Principle:
Principle #25Self-service

3Productivity

If nodes transmit without checking timing conditions of interference, then spatial reuse is maximized and throughput increases, but packet loss due to interference increases

Engineering Contradiction:
Improvespatial reuse efficiencyVSAvoidpacket delivery reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by having the receiving node perform preliminary RSSI measurements and timing condition assessments before determining whether to adjust the CCAT. The system proactively evaluates potential interference conditions based on timing relationships between transmissions and uses this advance information to prevent packet loss before it occurs.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3427532B1Methods for reducing interference in a wireless communications network
Publication Date: 2023.03.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3427532B1 patent drawingFigure 1
  • EP3427532B1 patent drawingFigure 2~3
  • EP3427532B1 patent drawingFigure 4

AI summary

A method performed by a transmitting node (110) for reducing interference in a wireless communications network (100) is provided. The transmitting node (110) receives information indicating that inference caused by an interfering node (111) to a transmission signal from the transmitting node (110) fulfills a timing condition relative to the reception of 5 the transmission signal in a receiving node (121) in the wireless communications network (100). Then, the transmitting node (110) adjusts one or more transmission parameters in the transmitting node (110) based on the received information. A transmitting node (110) is also provided. Furthermore, an interfering node (111) and a method therein for reducing 10 interference in a wireless communications network (100) are also provided, as well as, a receiving node (121) and a method therein for reducing interference in a wireless communications network (100).