Adaptive PD Threshold for OBSS Interference in Wireless Networks

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Solution Overview

Problem

Wireless networks face challenges in guaranteeing throughput and latency requirements for high-priority traffic, such as real-time gaming applications, due to unpredictable outcomes of medium access contention operations in shared wireless mediums, especially when contention levels are high.

Innovation Solution

Adjusting packet detect (PD) and energy detect (ED) thresholds based on received signal strength indicators (RSSI) and overlapping basic service set (OBSS) interference levels to optimize channel access parameters, allowing for increased access opportunities and improved performance metrics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If random channel access mechanisms (CSMA/CA) are used to control access to shared wireless medium, then medium access contention is managed, but unpredictable outcomes prevent guaranteeing throughput and latency requirements for high-priority traffic

Engineering Contradiction:

Improvethroughput and latency guaranteeVSAvoidunpredictable medium access outcome

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent dynamically adjusts the PD threshold based on real-time OBSS interference measurements. Instead of using a fixed threshold, the system continuously monitors the wireless medium for overlapping basic service set interference and adapts the packet detect threshold accordingly, enabling the system to respond to changing channel conditions and improve reliability for high-priority traffic

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the PD threshold parameter based on measured OBSS interference levels. By adjusting this critical parameter dynamically, the system can differentiate between acceptable interference and actual packet transmissions, thereby improving the predictability and reliability of medium access for high-priority traffic while maintaining coexistence with other networks

Inventive Principle:

Principle #35Parameter changes

2Reliability

If lower PD threshold is used to detect more packets, then collision avoidance improves, but access opportunities for high-priority traffic decrease due to more frequent channel deferral

Engineering Contradiction:

Improvecollision avoidanceVSAvoidaccess opportunity frequency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies different detection thresholds for different types of signals. By identifying OBSS packets specifically and measuring their interference levels, the system can determine whether to defer or proceed with transmission. This localized approach to threshold application allows the system to maintain high collision avoidance where needed while preserving access opportunities when OBSS interference is manageable

Inventive Principle:

Principle #3Local quality

3Productivity

If higher PD threshold is used to increase access opportunities, then throughput for high-priority traffic improves, but packet detection accuracy decreases leading to more collisions

Engineering Contradiction:

ImprovethroughputVSAvoidpacket detection accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the PD threshold based on measured OBSS interference levels rather than using a static high threshold. When OBSS interference is low, the system can use a higher effective threshold to increase access opportunities. When OBSS interference is high, the threshold is adjusted downward to maintain detection accuracy. This dynamic adaptation resolves the contradiction between throughput and detection accuracy

Inventive Principle:

Principle #15Dynamics

4Device complexity

If fixed channel access parameters are used, then system complexity is reduced, but ability to meet strict latency requirements under varying contention levels is compromised

Engineering Contradiction:

Improvechannel access parameter managementVSAvoidlatency requirement satisfaction

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The system performs self-adjustment of the PD threshold by automatically monitoring OBSS interference levels and adapting its detection parameters accordingly. This self-service capability eliminates the need for complex external configuration or manual parameter tuning, yet enables the system to meet strict latency requirements by responding autonomously to changing channel conditions

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system implements feedback by continuously measuring OBSS interference levels and using this information to adjust the PD threshold. This closed-loop approach allows the system to adapt to varying contention levels and maintain latency requirements without requiring complex external control mechanisms

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11357047B2Adaptive detection threshold for contention-based channel access

Publication Date: 2022.06.07 QUALCOMM INC

AI summary

This disclosure provides systems, methods and apparatuses for wireless communications. In some implementations, a first wireless communication device associated with a basic service set (BSS) receives a plurality of packets transmitted during a measurement window by a second wireless communication device associated with the BSS. The first wireless communication device determines a received signal strength indicator (RSSI) value of the plurality of received packets, determines a level of overlapping basic service set (OBSS) interference on the wireless medium during the measurement window, and adjusts one or more of a packet detect (PD) threshold, an OBSS PD threshold, or an energy detect (ED) threshold based on the determined RSSI value and the level of OBSS interference.