Wireless Station Access via CSMA/CA and OFDMA
Solution Overview
Problem
Existing wireless communication systems face inefficiencies in random access due to low parallel access capabilities on multiple channels, particularly in scenarios with multiple stations, leading to increased collision probabilities and decreased channel utilization.
Innovation Solution
Implementing a method and apparatus that enable multiple stations to perform parallel random access on multiple channels by managing channel access manners, including CSMA/CA and OFDMA, and utilizing trigger frames and timers to optimize channel access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple stations perform parallel random access on multiple channels, then random access efficiency is improved, but collision probability increases
Solution Approach 1:
The patent segments the channel access process into two distinct phases: a contention-based random access phase and a scheduled access phase. Stations are divided into groups, with some performing random access while others are scheduled by the AP, reducing overall collision probability while maintaining parallel access efficiency
Solution Approach 2:
The patent dynamically adjusts the access mechanism based on channel conditions and traffic requirements. The AP can switch between allowing random access and implementing scheduled access, and stations can transition between different access modes, optimizing the balance between efficiency and collision avoidance
2Productivity
If AP obtains channel by contention to organize multi-user transmission, then parallel access is enabled, but probability of successful channel acquisition needs to be increased
Solution Approach 1:
The patent implements preliminary actions by having stations send buffer status reports and access requests before actual data transmission. The AP performs preliminary channel assessment and station grouping, preparing the system in advance to reduce contention overhead and improve successful acquisition probability
Solution Approach 2:
The patent introduces trigger frames as intermediary signals that coordinate between stations and the AP. These trigger frames serve as mediators that organize multi-user transmissions without requiring full contention-based channel acquisition, reducing the probability requirement for successful channel acquisition
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Embodiments of the present invention provide an access method, including: sending, to an access point, a first frame that carries uplink transmission requirement information; and if a second frame that carries information about an uplink transmission resource is received from the access point within agreed time period, sending uplink multi-user transmission data to the access point, where the uplink multi-user transmission data is transmitted on the uplink transmission resource; or if the second frame is not received within an agreed time period, accessing, by a station, a channel in a contention access manner that is based on carrier sense CSMA/CA. According to the method provided in the embodiments of the present invention, a channel access manner can be managed, a congestion degree of a system can be decreased, and channel utilization can be increased.