Wireless Terminal Spatial Reuse Backoff Control
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Solution Overview
Problem
In wireless LAN systems, the existing spatial reuse technology faces challenges in maintaining communication quality and throughput when multiple terminals perform SR transmission, as they often interfere with each other, leading to reduced reception power and increased interference, causing deterioration in both self-cell and adjacent cell communication quality.
Innovation Solution
The proposed solution involves terminals performing random SR backoff based on interference power and propagation loss to adjust their transmission opportunities, with successful transmitters being penalized with additional backoff time to prevent monopolization of transmission opportunities, and the base station setting SR backoff parameters based on the number of terminals and throughput situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If terminals perform spatial reuse transmission to increase transmission opportunities, then system throughput is improved, but interference to adjacent cells increases and communication quality deteriorates
Solution Approach 1:
The patent adjusts transmission power levels and backoff time parameters dynamically based on detected adjacent cell signal conditions. Terminals modify their transmission parameters (power, timing) to enable spatial reuse while controlling interference, resolving the contradiction between increasing throughput and reducing harmful interference.
Solution Approach 2:
The system implements dynamic control where terminals continuously monitor adjacent cell signals and adjust their transmission behavior in real-time. This includes dynamically setting backoff times and transmission power based on current interference conditions, allowing the system to adaptively balance throughput and interference.
2Productivity
If terminals transmit packets immediately upon detecting adjacent cell signals, then transmission efficiency is improved, but packet collision probability increases
Solution Approach 1:
The patent implements a preliminary backoff mechanism before spatial reuse transmission. Terminals perform a reduced backoff procedure when detecting adjacent cell signals, which is shorter than conventional backoff but still provides collision avoidance. This preliminary action balances immediate transmission needs with collision prevention.
Solution Approach 2:
The system uses feedback from adjacent cell signal detection to control transmission timing. Terminals monitor the presence and strength of adjacent cell signals, and this feedback information directly determines whether to proceed with spatial reuse transmission or perform additional backoff, thereby managing collision risk while maintaining efficiency.
3Ease of operation
If terminals use fixed backoff time for spatial reuse transmission, then implementation is simplified, but transmission opportunities are not optimized based on interference conditions
Solution Approach 1:
The patent implements dynamic backoff time adjustment where the backoff duration is not fixed but adapts based on detected interference conditions. When adjacent cell signals are weak, terminals use shorter backoff times to capture more opportunities; when interference is strong, backoff times are extended. This dynamic approach optimizes throughput while maintaining manageable complexity through standardized adjustment rules.
Data Source
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AI summary
To provide a communication apparatus and a communication method for enabling spatial reuse between adjacent cells. A terminal which performs SR transmission by use of information available from an adjacent cell signal adjusts a SR backoff time by use of an intensity of its received interference power and information regarding a distance to AP and the like to acquire a transmission opportunity while avoiding packet collision. Further, a penalty of setting an additional backoff time is imposed on a terminal which has successfully performed SR transmission. Further, AP sets a parameter for adjusting a transmission standby time for STA depending on the number of its own terminals, a throughput situation, and the like.