Scoreboard Sharing for Non-Collocated Wi-Fi MLD Roaming

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Solution Overview

Problem

In non-collocated multi-link device (MLD) systems, achieving seamless mobility and zero handover for Time-Sensitive Networking (TSN) and Real-Time applications is challenging due to the stochastic nature of wireless channels and difficulties in packet reordering and transmission across different physical locations, leading to potential packet loss and increased latency.

Innovation Solution

Implementing scoreboard sharing among non-collocated multi-link sets to efficiently manage packet transmission and reordering, allowing for flexible and reliable communication by steering traffic streams and acknowledging sequence numbers across multiple links, thereby reducing redundant transmissions and latency during handover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If non-collocated multi-link sets are used to support mobility, then adaptability is improved, but packet reordering and transmission reliability deteriorate

Engineering Contradiction:
Improvemobility supportVSAvoidpacket transmission reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism (scoreboard sharing between multi-link sets) to coordinate packet transmission and reordering across non-collocated devices. The first multi-link set acts as an intermediary that receives packets, manages reordering, and forwards them to the second multi-link set, ensuring reliable delivery despite the distributed architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the packet transmission function across multiple multi-link sets located at different physical positions. The first multi-link set handles initial packet reception and reordering, while the second multi-link set handles final delivery, allowing mobility support while maintaining reliability through functional segmentation.

Inventive Principle:
Principle #1Segmentation

2Reliability

If packet reordering is implemented across multiple links, then transmission reliability is improved, but device complexity increases

Engineering Contradiction:
Improvepacket delivery reliabilityVSAvoidreordering management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the complex reordering management function from the distributed multi-link sets and consolidates it in the first multi-link set. This centralizes the complexity in one location while allowing other sets to operate more simply, reducing overall system complexity while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If seamless roaming is achieved during mobility, then adaptability is improved, but packet loss increases due to handover challenges

Engineering Contradiction:
Improveroaming capabilityVSAvoidpacket loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent performs preliminary actions by establishing the first multi-link set as an intermediary before mobility occurs. Packets are pre-processed and reordered at the first multi-link set, creating a buffer that prevents packet loss during subsequent handover operations to the second multi-link set.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4250819A1Enhanced roaming operations with reordering using scoreboard sharing for non-collocated wi-fi multi-link devices
Publication Date: 2023.09.27 INTEL CORP
  • EP4250819A1 patent drawingFigure 1~2
  • EP4250819A1 patent drawingFigure 3~4
  • EP4250819A1 patent drawingFigure 5~6

AI summary

This disclosure describes systems, methods, and devices related to Wi-Fi roaming operations for multi-link devices (MLDs). A MLD may determine, when the MLD is at a first physical location, that a first station device of the MLD is to switch from a first multi-link set of multiple multi-link sets to a second multi-link set of the multiple multi-link sets, and maintain at least one active link from the first multi-link set and at least one active link from the second multi-link set during a transition from the first multi-link set to the second multi-link set.