Dynamic Clear Channel Assessment Thresholds for Wireless Networks
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Solution Overview
Problem
Existing wireless communication systems relying solely on energy detect (ED) for clear channel assessment face inefficiencies due to high collision probabilities and inadequate detection of busy channels, especially when operating in unlicensed frequency bands like the 2.4 GHz band, leading to hidden node problems and performance degradation.
Innovation Solution
A network node and user device configuration that dynamically adjusts the energy detection threshold based on received signal power levels and path loss to optimize clear channel assessment, ensuring accurate channel state determination and minimizing collisions by setting appropriate transmit power levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed energy detection threshold (e.g., -62 dBm) is used for clear channel assessment, then the detection method is simple and device complexity is low, but collision probability increases and channel utilization efficiency deteriorates due to hidden node problems
Solution Approach 1:
The patent implements dynamic energy detection thresholds that adapt to channel conditions and device locations. Instead of using a fixed threshold, the system calculates device-specific thresholds based on path loss models and received signal power measurements, allowing each device to adjust its CCA behavior dynamically to reduce collisions while maintaining simple operation
Solution Approach 2:
The patent changes the detection threshold parameter from a fixed value to a dynamically calculated value based on received power levels and path loss characteristics. This parameter adaptation enables the system to optimize channel access decisions for different transmission scenarios without increasing operational complexity
2Device complexity
If a high energy detection threshold (e.g., -62 dBm) is used, then device complexity remains low, but measurement precision of channel state deteriorates leading to false idle channel declarations and increased collisions
Solution Approach 1:
The patent adjusts the detection threshold parameter dynamically based on the specific device's received power measurements and path loss characteristics. This allows the threshold to be optimized for each device's location and transmission conditions, improving measurement precision without requiring complex detection mechanisms
3Area of stationary object
If devices transmit at maximum power levels, then signal coverage area increases, but collision probability increases and reliability of communication decreases due to hidden node interference
Solution Approach 1:
The patent applies different transmit power levels to different devices based on their local channel conditions and detected interference levels. Instead of uniform maximum power transmission, each device adjusts its power locally to achieve sufficient coverage while minimizing interference to others, thereby improving overall communication reliability
Solution Approach 2:
The system uses feedback from received power measurements and collision detection to continuously adjust transmit power levels. Devices monitor the channel and adapt their transmission power based on observed conditions, maintaining reliable communication while reducing hidden node collisions
Data Source
AI summary
An aspect of the present disclosure is directed to a network node for performing communication in a wireless communication network. The network node is configured to receive a signal transmitted by a user device in the wireless communication network, measure a received power level at which the signal is received by the network node, determine, based on a predefined transmit power level of the network node, based on a predefined transmit power level of the user device and based on the received power level, a threshold power level for a clear channel assessment to be performed by the user device, and trigger transmitting an indication of the threshold power level to the user device. Further aspects of the disclosure pertain to a user device, methods and a computer program product.