Multi-Link Device Doze State Control for Power Reduction

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Solution Overview

Problem

In the EHT standard, multi-link devices that do not support Simultaneous TX/RX (STR) Channel access experience unnecessary power consumption during multi-link operations.

Innovation Solution

A multi-link device (MLD) comprising a first station (STA) and a second STA, where the first STA receives PPDU within a TXOP configured in the first link while the second STA is in a doze state, and upon receiving a control frame for truncation of the TXOP, the second STA changes its state from doze to awake.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a multi-link device operates multiple links simultaneously without STR capability, then link utilization may be maintained, but power consumption increases unnecessarily

Engineering Contradiction:

Improvelink utilizationVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the STA's operational state changeable between awake and doze states based on current transmission needs. The second STA dynamically transitions from awake to doze state when not actively transmitting, and wakes up only when necessary to receive control frames, optimizing the balance between link utilization and power consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements periodic action through the use of TXOP (Transmission Opportunity) structures where the second STA periodically wakes up to check for control frames at specific intervals, then returns to doze state. This periodic wake-up mechanism ensures link utilization is maintained while minimizing overall power consumption by keeping the STA in low-power mode most of the time.

Inventive Principle:

Principle #19Periodic action

2Use of energy by moving object

If the second STA remains in doze state during TXOP, then power consumption is reduced, but the STA must wake up to handle control frames

Engineering Contradiction:

Improvepower consumptionVSAvoidwake-up time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the first STA send a control frame indicating TXOP truncation before the second STA would naturally wake up. This allows the second STA to remain in doze state longer and only wake up when absolutely necessary, reducing both power consumption and unnecessary wake-up time.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the second STA wakes up continuously to monitor the first link, then link utilization is maintained, but power consumption increases

Engineering Contradiction:

Improvelink utilizationVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent uses the control frame as an intermediary mechanism that allows the first STA to notify the second STA of TXOP truncation without requiring continuous monitoring. The control frame acts as a mediator that bridges the information gap between the two STAs, enabling the second STA to stay in doze state while still being informed of link status changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12302248B2Technique for performing multi-link communication in wireless communication system

Publication Date: 2025.05.13 LG ELECTRONICS INC

AI summary

According to various embodiments, a multi-link device including a first STA and a second STA may receive, via the first STA, at least one PPDU within a transmission opportunity (TXOP) configured in a first link. While the at least one PPDU is received, the state of the second STA may be set to a doze state. The multi-link device may receive, via the first STA, a first control frame for the truncation of the TXOP. The multi-link device may change the state of the second STA from the doze state to an awake state on the basis of the first control frame.