HARQ Capability Indication in IEEE 802.11 MAC Frames

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Solution Overview

Problem

There is no mechanism for communication devices to recognize whether a partner device can execute Hybrid Automatic Repeat Request (HARQ) in existing wireless LAN standards, preventing efficient data transmission using HARQ technology.

Innovation Solution

A communication device transmits or receives a radio frame conforming to the IEEE 802.11 standard series, indicating its HARQ capability within the MAC frame, allowing devices to mutually recognize and determine the HARQ type for data transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HARQ capability indication is added to MAC frame, then communication devices can recognize partner device HARQ capabilities, but device complexity increases due to additional frame processing requirements

Engineering Contradiction:

ImproveHARQ capability recognitionVSAvoidMAC frame processing

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The HARQ capability indication is merged into the existing MAC frame structure by utilizing the Capability Information field. This allows the HARQ capability to be transmitted along with other capability information without requiring a separate signaling mechanism, thereby reducing additional device complexity while enabling partner devices to recognize HARQ capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The Capability Information field in the MAC frame is designed to serve multiple functions: it carries both general capability information and specific HARQ capability indication. This multi-functionality approach allows the same field to provide diverse information without increasing the overall frame structure complexity, enabling devices to recognize HARQ capabilities using existing frame processing mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If HARQ with soft combining is implemented, then data transmission efficiency improves, but compatibility with conventional standards decreases

Engineering Contradiction:

Improvedata transmission efficiencyVSAvoidstandard compatibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts between conventional ARQ and HARQ with soft combining based on the capability indication exchanged between devices. When a device indicates HARQ capability, the system switches to HARQ mode for improved efficiency; when not indicated, it maintains compatibility with conventional standards using ARQ. This dynamic adaptation allows the system to optimize performance while preserving backward compatibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The HARQ capability indication acts as a parameter that changes the communication mode between devices. By setting this parameter through capability exchange, devices can switch between different transmission protocols (conventional ARQ vs. HARQ with soft combining), allowing efficient HARQ operation when supported while maintaining standard compatibility when not supported.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11923986B2Communication device, communication method, and computer-readable storage medium

Publication Date: 2024.03.05 CANON KK

AI summary

A communication device transmits to a communication partner device or receives from the partner device a radio frame conforming to an IEEE 802.11 standard series, wherein a capability of HARQ (Hybrid Automatic Repeat reQuest) that a device that transmitted the radio frame has is indicated in a MAC (media access control) frame of the radio frame.