Trigger Frame Multiple Start Times WLAN Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless local area networks (WLANs), especially those operating under IEEE 802.11 standards, there is a challenge in providing low-latency communications to stations (STAs) within a Basic Service Set (BSS) due to channel busy conditions, which restricts the reuse of channel resources and increases latency when multiple STAs or access points (APs) contend for the medium.
Innovation Solution
Implementing a trigger frame mechanism that allows STAs to delay their uplink transmissions and start at multiple time allocations within a resource unit (RU), enabling random access and multiplexing, thereby reducing latency by allowing urgent packets to be transmitted even if the AP is not aware of their arrival and providing flexibility in packet scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple STAs contend for channel resources using traditional protocols, then channel resource sharing is achieved, but latency increases due to channel busy conditions and restricted resource reuse
Solution Approach 1:
The trigger frame schedules multiple time allocations (e.g., T1, T2, T3) within a single resource unit, dividing the transmission opportunity into segments. This allows different STAs to transmit at different times without waiting for the entire contention process, thereby reducing latency while maintaining efficient resource sharing.
Solution Approach 2:
The AP transmits the trigger frame in advance that pre-schedules multiple time allocations for uplink transmissions. This preliminary scheduling eliminates the need for STAs to wait for channel availability during contention, as their transmission times are predetermined, thus reducing latency while enabling efficient channel resource utilization.
2Reliability
If STAs must wait for AP acknowledgment before transmitting urgent packets, then protocol compliance is maintained, but express channel access for time-sensitive data is blocked
Solution Approach 1:
The system introduces dynamic scheduling where the trigger frame can allocate different time allocations to different STAs based on their transmission needs. This dynamic approach allows urgent packets to be transmitted in dedicated time slots without waiting for AP acknowledgment, while maintaining protocol compliance through structured scheduling mechanisms.
Solution Approach 2:
The trigger frame divides the transmission opportunity into multiple time allocations, allowing urgent packets to be scheduled in specific time slots independent of the AP acknowledgment timing. This segmentation enables express channel access for time-sensitive data while maintaining protocol structure through defined scheduling rules.
3Device complexity
If channel resources are allocated to single STAs sequentially, then resource allocation simplicity is maintained, but bandwidth utilization and response times deteriorate
Solution Approach 1:
Multiple time allocations (T1, T2, T3) and resource units are combined within a single trigger frame scheduling opportunity. This merging allows the AP to allocate resources to multiple STAs simultaneously in a structured manner, improving bandwidth utilization and response times while maintaining manageable allocation complexity through unified trigger frame control.
Solution Approach 2:
The AP performs preliminary scheduling in the trigger frame that allocates multiple time allocations and resource units to different STAs in advance. This preliminary action enables efficient bandwidth utilization and fast response times by pre-determining resource assignments, while maintaining allocation simplicity through a single trigger frame structure.
4Adaptability or versatility
If legacy protocol constraints are enforced, then backward compatibility is maintained, but hardware bandwidth limitations and protocol version restrictions reduce system performance
Solution Approach 1:
The trigger frame mechanism provides universal scheduling capability that works across different protocol versions and hardware configurations. By defining multiple time allocations and resource units in a standardized format, the system achieves multi-functionality that maintains backward compatibility while enabling improved system performance through efficient resource allocation.
Solution Approach 2:
The system changes scheduling parameters by introducing multiple time allocations and resource unit configurations within the trigger frame. This parameter change enables enhanced system performance and bandwidth utilization while maintaining compatibility with legacy protocols through standardized trigger frame structures that can be interpreted by different protocol versions.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Methods, apparatuses, and computer readable media for trigger frames or transmission opportunities with multiple start times and delayed uplink start are disclosed. Apparatuses of a station (STA) are disclosed, where the apparatuses comprise processing circuitry configured to decode a trigger frame, the trigger frame indicating a time allocation of a plurality of time allocations and indicating a resource unit (RU) for an uplink transmission for the STA. The processing circuitry is further configured to: encode an uplink (UL) trigger-based (TB) physical (PHY) protocol data unit (PPDU) in accordance with the time allocation and the RU and configure the STA to transmit the UL TB PPDU on the RU during the time allocation. Trigger frames are disclosed that include indications of multiple time allocations for multiple RUs where the STAs are permitted to use delayed transmissions or random access within the time allocations.