Queue Management for EDCA Coexistence in Wireless Networks
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Solution Overview
Problem
Existing communication networks face challenges in managing coexistence between direct link and multi-user uplink communication mechanisms, particularly in wireless local area networks, where direct link transmissions cannot use the multi-user uplink access scheme coordinated by an access point, leading to inefficiencies and unsatisfactory quality of service.
Innovation Solution
A method of queueing data frames in communication stations that selects traffic queues based on transmission modes, such as direct link or uplink, and prioritizes them accordingly, allowing for the modification of transmission modes to ensure coexistence between direct link and multi-user uplink communications by routing data frames through the access point when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct link transmissions are allowed between peer stations, then transmission efficiency and bandwidth usage are improved, but coexistence with multi-user uplink mechanism becomes difficult
Solution Approach 1:
The patent applies dynamics by making the transmission mode flexible and changeable. Each traffic queue can dynamically switch between SU mode and MU UL mode based on whether it contains direct link frames or uplink frames. This dynamic adaptation allows the system to optimize for direct link transmission efficiency when needed while maintaining compatibility with MU UL mechanism when uplink traffic is present, thereby resolving the contradiction between transmission efficiency and coexistence capability.
Solution Approach 2:
The patent segments the traffic queues into different transmission modes (SU mode and MU UL mode) based on their content. By dividing the queue management into separate modes, direct link frames and uplink frames are handled differently, allowing direct link transmissions to occur efficiently in SU mode while uplink traffic maintains compatibility with MU UL mechanism in MU UL mode, thus enabling coexistence.
2Adaptability or versatility
If all data frames are routed through the access point, then coexistence between transmission mechanisms is improved, but latency and bandwidth usage deteriorate
Solution Approach 1:
The system dynamically determines the transmission mode for each traffic queue based on its content. When a queue contains only direct link frames, it operates in SU mode, allowing direct transmission between peer stations without routing through the AP, thereby reducing latency. When uplink frames are present, the queue switches to MU UL mode for proper coordination. This dynamic approach resolves the contradiction by enabling low-latency direct transmission when possible while maintaining coexistence through AP coordination when necessary.
3Reliability
If multi-user uplink access scheme is used, then collision probability is reduced, but direct link communications lose the ability to use this efficient mechanism
Solution Approach 1:
The patent segments the communication mechanism into two distinct paths: direct link mode for peer-to-peer communications and MU UL mode for AP-coordinated uplink. This segmentation allows direct link communications to operate independently without being constrained by MU UL requirements, while still enabling MU UL mechanism to provide collision avoidance benefits when uplink traffic is present. Each segment optimizes for its specific use case, resolving the contradiction between collision avoidance and access scheme availability.
Solution Approach 2:
The patent changes the transmission mode parameter of traffic queues based on their content. When a queue contains direct link frames, it is configured in SU mode with appropriate parameters for direct transmission. When uplink frames are detected, the queue parameters are changed to MU UL mode. This parameter change mechanism enables direct link communications to use efficient direct access while allowing MU UL mechanism to provide collision avoidance when needed, resolving the contradiction.
Data Source
AI summary
The present invention provides according to one of its aspects a method of queueing a data frame in one of a plurality of traffic queues at a communication station for transmission over a communication channel in a communication network comprising a plurality stations and an access point (AP). The method comprising selecting a traffic queue based on at least one of 1) a transmission mode, direct link or uplink, of the data frame, and 2) a transmission mode of the traffic queue; and queueing the data frame in the selected traffic queue. The transmission mode of the traffic queue may be a Multi-User (MU) uplink (UL) mode if a data frame previously stored in the traffic queue has been transmitted, since a predetermined period of time, in a resource unit (RU) provided by the AP within a transmission opportunity granted to the AP on the communication channel. The transmission mode may also be a Single-User (SU) mode.