WLAN Access Point Contention Window Synchronization
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Solution Overview
Problem
Existing wireless local area network (WLAN) systems face inefficiencies in multi-user parallel transmission, particularly in setting competition parameters for uplink access categories (AC) after a trigger frame is sent in a competitive manner, leading to unsynchronized competition parameters between the access point (AP) and non-AP stations.
Innovation Solution
The method involves sending a trigger frame by the AP to non-AP stations to initiate uplink multi-user (UL MU) transmission, resetting the contention window (CW) of the AC to an initial value upon data receipt, and adjusting buffer queue length parameters to synchronize competition parameters across the AP and non-AP stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the AP sends a trigger frame to initiate UL MU transmission in a competitive manner, then the network can support multi-user parallel transmission and improve throughput, but the competition parameters (CW values) between the AP and non-AP stations become unsynchronized, leading to inefficiencies in channel access
Solution Approach 1:
The patent implements a feedback mechanism where the AP monitors the completion of UL MU transmissions and sends feedback information to non-AP stations. When the AP successfully receives data from all scheduled stations, it triggers a feedback signal that causes both the AP and stations to reset their CW values to initial values, ensuring synchronized competition parameters for the next transmission opportunity.
Solution Approach 2:
The patent enables the system to automatically adjust competition parameters without external intervention. The AP and non-AP stations autonomously reset their CW values based on transmission completion status, with the AP serving itself by monitoring its own reception status and triggering the reset mechanism, while stations self-adjust based on receiving the feedback signal.
2Reliability
If the CW window increases exponentially after transmission collision, then the system can handle collision scenarios, but the competition parameters become desynchronized between AP and stations, reducing network efficiency
Solution Approach 1:
The patent uses feedback from the AP to stations to coordinate CW resets. When collisions occur and CW values are increased, the AP monitors the situation and sends feedback signals that trigger synchronized resets for both the AP and stations, ensuring that collision handling does not lead to long-term parameter desynchronization and maintains network efficiency.
3Ease of operation
If the AP triggers UL MU transmission using scheduled information, then the transmission process is organized and efficient, but the competition parameters for subsequent transmissions are not properly reset, leading to parameter drift
Solution Approach 1:
The patent complements the scheduled transmission mechanism with a feedback-based reset mechanism. After scheduled UL MU transmission completes successfully, the AP sends feedback that triggers both the AP and stations to reset their CW values, ensuring that the organizational benefits of scheduled transmission do not accumulate parameter drift over multiple transmission cycles.
Data Source
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AI summary
Provided in the present invention are a method and device for competitive transmission. The method comprises: an access point transmits a trigger frame or a radio frame carrying a trigger information domain to a non-access point to trigger the non-access point to perform uplink multiuser transmission; and, when data transmitted by the non-access point is received by the access point, same resets a competitive window of an access type to an initial value. The present invention solves the problem in the prior art of how to process competitive parameters of an access point side and a non-access point side when a trigger frame is transmitted in a competitive manner, thus ensuring that the competitive parameters of a same queue of stations of the access point side and of the non-access point side can be kept synchronous, and at the same time displaying busy/idle states of a channel.