WLAN Short Packet Aggregation with Multi-WTRU Block ACKs

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Solution Overview

Problem

Existing WLAN systems face inefficiencies in acknowledging short packets, particularly in high-density scenarios, leading to increased overhead and delays due to individual ACKs for multiple users, especially with UL MU-MIMO and OFDMA technologies.

Innovation Solution

Implementing multi-WTRU block acknowledgment (BA) frames and aggregation mechanisms to efficiently acknowledge multiple users simultaneously, optimizing ACKs for both DL and UL transmissions, including formats that support MU-MIMO and OFDMA.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If individual ACKs are sent for multiple users in high-density WLAN scenarios, then each user receives reliable acknowledgment, but medium access overhead and delay increase significantly

Engineering Contradiction:
ImproveACK reliabilityVSAvoidMedium access delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines multiple individual ACKs into a single multi-WTRU block acknowledgment frame. The AP aggregates acknowledgments for multiple users (WTRUs) into one consolidated frame that contains acknowledgment information for all users, thereby reducing the number of separate transmission opportunities needed and decreasing medium access delay while maintaining reliable delivery of ACKs to each user.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-WTRU block acknowledgment frame serves multiple functions simultaneously: it acknowledges receipts for multiple different users in a single frame, supports both DL and UL transmission directions, and can accommodate various packet types. This multi-functionality reduces overhead compared to sending separate ACKs for each user and transmission type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If individual ACKs are sent for multiple users, then each transmission is acknowledged separately, but MAC efficiency decreases due to increased overhead

Engineering Contradiction:
ImproveTransmission acknowledgmentVSAvoidMAC efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Multiple individual acknowledgment transmissions are merged into a single multi-WTRU block acknowledgment frame. This consolidation reduces the total number of MAC protocol data units (MPDUs) that need to be processed and transmitted, thereby improving MAC layer efficiency while ensuring that each user's transmission is still reliably acknowledged through the aggregated frame.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If separate ACK mechanisms are used for DL and UL transmissions, then each direction is handled independently, but system complexity increases

Engineering Contradiction:
ImproveDirection-specific acknowledgmentVSAvoidACK mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The multi-WTRU block acknowledgment frame is designed as a universal mechanism that can handle both downlink (DL) and uplink (UL) transmission acknowledgments within the same frame structure. The frame includes fields that can indicate acknowledgment status for multiple users and multiple transmission directions, thereby simplifying the overall system by using a single unified ACK mechanism rather than separate mechanisms for each direction.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3266136B1Short packet optimization in WLAN systems
Publication Date: 2025.08.27 INTERDIGITAL PATENT HOLDINGS INC
  • EP3266136B1 patent drawingFigure 1A
  • EP3266136B1 patent drawingFigure 1B
  • EP3266136B1 patent drawingFigure 1C

AI summary

Mechanisms may be used for aggregating acknowledgement (ACK), block ACK (BA) and/or short packets transmissions for multi-user (MU) wireless communication systems. Aggregation mechanisms may be used for uplink (UL) and/or downlink (DL) orthogonal frequency division multiple access (OFDMA), and/or UL/DL multiple-user multiple input multiple output (MU-MIMO) transmissions, for example. Multi-user short packets may be aggregated and/or simultaneously transmitted for DL, UL, or peer-to-peer (P2P) transmissions.