EMLSR TWT Link ID Bitmap for Multi-Link Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current IEEE 802.11 specifications lack detailed definitions for target wake time (TWT) operations between access point (AP) multi-link devices (MLD) and non-AP MLDs in enhanced multi-link single-radio (EMLSR) mode, limiting concurrent TWT agreements to a single radio non-AP MLD.
Innovation Solution
A method and apparatus enabling EMLSR TWT operation by allowing a first MLD to establish concurrent TWT agreements with a second MLD on multiple links through a TWT request and response mechanism, using a Link ID Bitmap subfield to indicate the links for agreement, and enabling EMLSR mode to synchronize wake times across multiple links.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If concurrent TWT agreements are established on multiple links for a single-radio non-AP MLD, then wireless communication efficiency is improved, but the system complexity increases due to lack of detailed specification definitions
Solution Approach 1:
The patent segments the TWT agreement establishment process into distinct phases: capability indication phase (where the non-AP MLD indicates EMLSR support), negotiation phase (where concurrent TWT agreements are established on multiple links), and execution phase (where wake times are synchronized). This segmentation allows complex multi-link operations to be managed through structured, step-by-step procedures defined in the specification.
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of standardized TWT request and response frames that mediate the agreement establishment between AP MLD and non-AP MLD. These frames contain specific fields (such as TWT element, link identifier, wake time parameters) that facilitate structured negotiation and reduce system complexity by providing a predefined communication protocol.
2Use of energy by moving object
If EMLSR mode enables concurrent TWT agreements on multiple links, then power efficiency is improved through synchronized wake times, but the operational complexity increases
Solution Approach 1:
The patent applies preliminary action by establishing TWT agreements and determining wake time schedules in advance before actual data transmission. The non-AP MLD and AP MLD negotiate and finalize concurrent TWT agreements on multiple links beforehand, allowing the non-AP MLD to enter sleep mode with predetermined wake times, thus improving power efficiency while reducing real-time operational complexity.
Solution Approach 2:
The patent implements periodic action through scheduled TWT service periods where the non-AP MLD wakes up at predetermined intervals to exchange data frames with the AP MLD on multiple links. This periodic wake-sleep pattern allows the device to optimize power consumption by remaining in low-power state between scheduled wake times while maintaining structured communication rhythm.
Data Source
Figure 1
Figure 2(A)~2(B)
Figure 3(A)~3(B)
AI summary
A first multi-link device, MLD, enables an enhanced multi-link single-radio, EMLSR, mode (610) and establishes concurrent target wake time, TWT, agreements with a second MLD on multiple links, including at least a first link and a second link of a plurality of links (620). In establishing the concurrent TWT agreements, a first station, STA, affiliated with the first MLD transmits a TWT request to a first peer STA affiliated with the second MLD, the TWT request containing a TWT element that comprises a Link Identifier, ID, Bitmap subfield indicating the multiple links on which the concurrent TWT agreements are requested to be established (622). In response, the first STA receives a TWT response from the first peer STA, the TWT response containing another TWT element that comprises another Link ID Bitmap subfield indicating the multiple links on which the concurrent TWT agreements are agreed to be established (624).