Wireless Carrier Sensing with Intermittent Signal Averaging
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Solution Overview
Problem
Carrier sensing in wireless communication systems often results in transmission delays due to the need to measure wireless signal intensity for a predetermined period, even if the signal intensity drops below the threshold after initial determination, preventing immediate data transmission.
Innovation Solution
A wireless communication method and apparatus that intermittently capture and retain intensity indication data, calculate averages with a frequency corresponding to data capture frequency, and enable transmission when the average signal intensity is less than or equal to a threshold, allowing for immediate data transmission when conditions become favorable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wireless signal intensity is measured for a predetermined period before transmission according to IEEE 802.15.4 standard, then transmission interference is prevented, but transmission delay increases
Solution Approach 1:
The system performs preliminary carrier sensing to detect ongoing transmissions, and when no transmission is detected, it immediately transmits data without waiting for the full predetermined measurement period. This preliminary check allows the system to bypass the standard's full measurement requirement when conditions permit, reducing delay while maintaining interference prevention.
Solution Approach 2:
The patent implements dynamic adjustment of the measurement period based on real-time channel conditions. When the channel is clear, the measurement period is shortened or eliminated; when transmissions are detected, the full measurement period is used. This dynamic approach resolves the contradiction by adapting the reliability measure to actual conditions rather than applying a fixed measurement period.
2Loss of time
If average signal intensity is calculated at high frequency, then transmission opportunities are captured sooner, but processing load increases
Solution Approach 1:
The system performs carrier sensing at a lower frequency (partial action) rather than continuously calculating averages at high frequency. By sampling the channel at intervals and using these partial measurements to determine transmission opportunities, the system reduces processing load while still capturing transmission opportunities in a timely manner.
Solution Approach 2:
The patent replaces continuous mathematical averaging calculations with a simpler threshold-based comparison mechanism. Instead of continuously computing moving averages, the system compares instantaneous or periodically sampled signal intensity values against a threshold, substituting complex mechanical computation with a simpler decision rule that achieves the same goal with less processing load.
Data Source
AI summary
A wireless communication method and apparatus that produce only a small amount of transmission delay even when carrier sensing is performed. Intensity indication data indicating the radio wave intensity of a received wireless signal is generated. The intensity indication data is intermittently captured and retained. An average of the retained intensity indication data is calculated. If the average is less than or equal to a threshold, a wireless transmission operation is enabled. The average is calculated with a frequency according to the frequency of capturing of the intensity indication data. The average and the threshold are compared at a frequency corresponding to the frequency of calculation of the average.