CTS Duration Setting for Shared TXOP Protection in Wi‑Fi STAs

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Solution Overview

Problem

The challenge in the 802.11be standard is setting the duration field of frames accurately during triggered Transmission Opportunity (TXOP) sharing procedures to ensure that non-AP STAs protect the shared time resources from being occupied by other users.

Innovation Solution

The STA sets the duration field of the Clear-To-Send (CTS) frame based on the duration field in the Multiple-User Request-To-Send Transmission Opportunity Sharing Trigger Frame (MU-RTS TXS TF) or first indication information, ensuring the CTS frame protects the shared time resources until the end of the AP's sharing time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the STA sets the duration field of the CTS frame based on conventional single protection settings, then the CTS frame can protect transmission time, but the protection duration is insufficient to cover the entire shared TXOP time resources

Engineering Contradiction:

Improvetime resource protectionVSAvoidshared TXOP time resources occupation

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The AP sends indication information (such as a new duration field or first indication information) in advance within the MU-RTS TXS TF to tell the STA how to set the CTS frame duration field. This preliminary action enables the STA to configure the CTS frame with the correct protection duration before transmission, ensuring the protection covers the entire shared TXOP period rather than just the CTS frame transmission time.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the duration field of the CTS frame is set to cover the entire shared TXOP period, then time resource protection is improved, but the complexity of determining the correct duration increases

Engineering Contradiction:

Improvetime resource protectionVSAvoidduration field setting complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The AP acts as an intermediary by sending indication information (new duration field or first indication information) in the MU-RTS TXS TF to guide the STA on how to set the CTS frame duration field. This intermediary mechanism simplifies the STA's task by providing ready-made duration values or calculation rules, avoiding the need for the STA to independently calculate complex duration values while ensuring accurate time resource protection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4325981B1Wireless communication methods, site devices, and access point devices

Publication Date: 2026.02.11 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

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AI summary

Wireless communication methods, station devices, and access point devices, a method comprising: a first site receiving a multiple-user request-to-send transmission opportunity sharing trigger frame (MU-RTS-TXS TF); and the first site configuring, according to time information and/or first indication information indicated by a duration field in the MU-RTS-TXS TF, time information indicated by a duration field in a clear-to-send (CTS) frame, the first indication information being used to indicate time information of an access point sharing part of an obtained transmission opportunity (TXOP) to at least one site.