Wireless LAN Preamble Signaling for Multi-AP Recognition

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Solution Overview

Problem

Existing wireless LAN communication standards, such as IEEE802.11ax, do not account for a station (STA) concurrently communicating with multiple access points (APs), lacking a mechanism for the STA to recognize frames transmitted from multiple APs.

Innovation Solution

A communication device that transmits radio frames with a preamble including L-STF, L-LTF, L-SIG, EHT-SIG-A, EHT-STF, and EHT-LTF, where EHT-SIG-A includes a subfield indicating concurrent data transmission from multiple APs to a common partner device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If conventional wireless LAN standards (IEEE802.11ax) are used, then communication compatibility is maintained, but the STA cannot recognize frames transmitted from multiple APs concurrently

Engineering Contradiction:

ImproveRecognition of concurrent transmissions from multiple APsVSAvoidFrame structure complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The patent embeds a multi-AP indicator field within the existing EHT-SIG-A structure, nesting the new functionality inside the conventional frame format. This allows the STA to recognize concurrent transmissions from multiple APs without fundamentally changing the overall frame structure, thus adding information capability while controlling complexity growth.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent segments the signal field into EHT-SIG-A and EHT-SIG-B, with the multi-AP indicator specifically placed in EHT-SIG-A. This segmentation allows the multi-AP recognition feature to be isolated in a specific subfield, making it easier to process and interpret without requiring the STA to parse the entire frame structure differently.

Inventive Principle:

Principle #1Segmentation

2Productivity

If multi-AP concurrent transmission is implemented, then throughput is improved, but the mechanism for STA recognition is lacking

Engineering Contradiction:

ImproveThroughputVSAvoidCommunication reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces a feedback mechanism where the multi-AP indicator in the frame provides explicit information to the STA about concurrent transmissions. This feedback allows the STA to reliably identify and manage multiple simultaneous transmissions, ensuring proper reception and acknowledgment handling, thus maintaining communication reliability while enabling multi-AP throughput improvement.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If a subfield indicating concurrent transmission is added to EHT-SIG-A, then STA recognition capability is enhanced, but frame structure complexity increases

Engineering Contradiction:

ImproveSTA recognition capabilityVSAvoidFrame structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by adding the multi-AP indicator specifically to the EHT-SIG-A field where it is most needed for multi-AP operation, rather than modifying the entire frame structure. This localized addition enhances STA recognition capability for concurrent transmissions while minimizing the impact on overall frame structure complexity and maintaining backward compatibility with single-AP operations.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12445902B2Communication device, communication method thereof, information processing device, control method thereof, and computer-readable storage medium

Publication Date: 2025.10.14 CANON KK

AI summary

A communication device communicates a radio frame including a preamble and a data field of a physical layer (PHY). The preamble includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal Field), an EHT-SIG-A (Extremely High Throughput Signal A Field), an EHT-STF (EHT Short Training Field), and an EHT-LTF (EHT Long Training Field), and the EHT-SIG-A includes a subfield indicating whether data are concurrently transmitted from a plurality of communication devices to a common partner device.