Carrier Sensing Backoff Counter Reconfiguration in Unlicensed Bands
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Solution Overview
Problem
Wireless access systems supporting unlicensed bands face challenges in reliably determining the idle or busy state of serving cells, which affects data transmission and reception efficiency.
Innovation Solution
A method involving carrier sensing in a wireless access system that selects a backoff counter value, performs carrier sensing until the threshold is reached, transmits data during a transmission opportunity section, and reconfigures the backoff counter based on reception state feedback, allowing for efficient determination of channel states in unlicensed bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carrier sensing is performed in unlicensed bands to determine channel state, then data transmission reliability is improved, but system complexity increases due to backoff counter management and reception state feedback processing
Solution Approach 1:
The patent implements a feedback mechanism where the receiver sends reception state feedback (ACK/NACK) to the transmitter. The transmitter uses this feedback to reconfigure the backoff counter value, creating a closed-loop control system that adapts to channel conditions and improves transmission reliability while managing complexity through structured feedback processing.
Solution Approach 2:
The backoff counter value is dynamically adjusted based on reception state feedback rather than being fixed. This dynamic adaptation allows the system to respond to changing channel conditions in unlicensed bands, improving reliability by avoiding collisions and optimizing transmission opportunities.
2Productivity
If backoff counter value is reconfigured based on reception state feedback, then transmission efficiency is improved, but processing time increases
Solution Approach 1:
The carrier sensing and backoff counter reconfiguration occur periodically at defined intervals ( Transmission Opportunity sections). This periodic structure allows the system to balance feedback processing time with transmission efficiency by concentrating processing activities at specific moments rather than continuously.
3Measurement precision
If carrier sensing is performed until backoff counter reaches threshold, then channel state determination accuracy is improved, but channel occupancy time increases
Solution Approach 1:
The backoff counter mechanism performs preliminary carrier sensing before actual data transmission. By counting down the backoff counter and performing sensing in advance, the system determines channel availability beforehand, ensuring accurate channel state determination while limiting the time spent in the sensing phase to the duration of the backoff period.
Data Source
AI summary
The present invention relates to methods for supporting carrier sensing in a wireless access system supporting an unlicensed band, and devices supporting same. A method for supporting carrier sensing in a wireless access system supporting an unlicensed band, according to an embodiment of the present invention, comprises the steps of: selecting a backoff counter value for performing carrier sensing; performing carrier sensing in a serving cell (S-cell) until the backoff counter value reaches a predetermined threshold value; when the backoff counter value reaches the predetermined threshold value, transmitting data in a transmission opportunity (TXOP) interval; receiving a reception state feedback indicating whether the transmitting of data is success, collision or error; and resetting the backoff counter value on the basis of the reception state feedback, wherein the S-cell can be configured in an unlicensed band.