Channel Reservation Method for WLAN Collision Reduction
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Solution Overview
Problem
In WLAN systems, the high collision probability of RTS frames and increased system overheads due to intensive AP and STA deployment lead to reduced efficiency, with existing solutions like RTS/CTS protocols failing to effectively address the hidden node problem.
Innovation Solution
A channel reservation method where a sender device indicates a moment for multiple receiver devices to send channel reservation frames simultaneously, reducing contention and modifying network allocation vectors only for coordinated devices, thereby minimizing collisions and overheads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RTS/CTS protocol is used to protect transmission, then hidden node problem is resolved, but collision probability of RTS frames increases and system overheads increase
Solution Approach 1:
The patent combines multiple channel reservation frames from different devices into a single aggregated frame. Instead of each device sending individual RTS frames that may collide, the access point aggregates reservations from multiple stations into one frame, reducing the number of transmissions and collision probability while still resolving hidden node problems for all devices.
Solution Approach 2:
The access point performs preliminary aggregation of channel reservation information from multiple devices before transmitting the consolidated reservation frame. This preliminary action allows the system to establish channel reservations for multiple devices in advance, reducing subsequent contention and improving overall system efficiency while maintaining reliable hidden node resolution.
2Productivity
If multiple devices send channel reservation frames simultaneously, then system overheads are reduced, but collision probability increases
Solution Approach 1:
The access point acts as an intermediary that receives individual channel reservation requests from multiple devices, aggregates them, and then transmits the consolidated reservation frame. This intermediary role prevents direct collisions between device transmissions while still achieving overhead reduction through centralized aggregation and single-frame transmission to multiple recipients.
3Reliability
If contention window length doubles after collision, then collision avoidance is improved, but system efficiency decreases
Solution Approach 1:
The system performs preliminary aggregation of channel reservation information before transmission, preventing collisions in the first place. By consolidating multiple reservations into a single frame at the access point, the need for collision avoidance mechanisms like doubling contention window length is eliminated, maintaining system efficiency while still achieving reliable collision avoidance.
Data Source
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AI summary
The present invention discloses a channel reservation method and a communications device. The method includes: generating, by a first device, a first indication frame, where the first indication frame is used for indicating a moment at which a second device sends a channel reservation frame, and the channel reservation frame is used for reserving a channel to be used when the first device sends data to the second device; and sending, by the first device, the first indication frame to multiple second devices. In the channel reservation method in embodiments of the present invention, a sender device in a data transmission process indicates a moment at which a receiver device sends a channel reservation frame, so that multiple receiver devices in the data transmission process send channel reservation frames at the same time, which avoids contention between the receiver devices in current data transmission, thereby reducing a collision probability, and reducing system overheads.