Orchestrated Wi-Fi Roaming for Ordered Multi-Link Handover
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Solution Overview
Problem
Existing wireless communication systems face challenges in seamless roaming for devices with dual radios, particularly in multi-link operations, as they fail to account for queued data at source access points and the integrity of media access control service data units, leading to potential loss, duplication, or out-of-order delivery during transitions.
Innovation Solution
Implementing orchestrated roaming techniques that involve agreeing on transition parameters, including sequence numbers and time conditions, between the client entity and infrastructure entities to ensure seamless handover, maintaining data integrity and reducing queue sizes at source access points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing roaming techniques are used for dual-radio devices in multi-link operations, then device mobility is supported, but data integrity is compromised due to queued data loss and MSDU stream corruption
Solution Approach 1:
The patent applies preliminary action by having the source access point transfer queued data to the target access point before the client device completes the roaming transition. This advance data transfer ensures that when the client switches to the target AP, all data is already available, preventing data loss and maintaining stream integrity without disrupting the seamless roaming experience.
Solution Approach 2:
The patent uses the target access point as an intermediary to receive and buffer data from the source access point before the client device completes roaming. This intermediary mechanism allows the data to be staged at the target AP, ensuring continuous data flow and maintaining MSDU stream integrity during the transition period.
2Reliability
If data is queued at source access point during roaming, then data completeness is improved, but queue management complexity increases
Solution Approach 1:
The source access point performs preliminary action by identifying and transferring queued data to the target access point before the roaming transition completes. This advance transfer simplifies queue management by clearing the source AP's queues in advance, reducing the burden of managing suspended queues during roaming while ensuring data completeness.
Solution Approach 2:
The patent extracts queued data from the source access point's data structures and transfers it to the target access point. This extraction removes the complexity of managing queues at the source AP during roaming, as the data is removed and relocated to the target AP where it can be seamlessly delivered to the roaming client.
3Speed
If roaming transition occurs without coordinating data transfer, then transition speed is improved, but data loss and duplication occur
Solution Approach 1:
The patent implements preliminary action by coordinating data transfer from source to target access point before the roaming transition completes. This coordinated approach maintains fast roaming speeds while preventing data loss and duplication, as the target AP is pre-loaded with the necessary data and both APs can track the sequence numbers to ensure accurate delivery.
Solution Approach 2:
The patent uses feedback mechanisms where access points track and communicate sequence numbers of transferred data. This feedback allows the source and target APs to coordinate their data transfer and delivery, ensuring that data is not lost or duplicated during the fast roaming transition by verifying the completeness and ordering of transferred MSDUs.
Data Source
AI summary
Techniques for wireless device roaming are disclosed. These techniques include identifying a wireless client entity for roaming from a first infrastructure entity to a second infrastructure entity. The techniques further include agreeing, between the client entity and the first infrastructure entity, on one or more roaming conditions defined using transition parameters for transition of a first data flow for the client entity from the first infrastructure entity to the second infrastructure entity, the one or more transition parameters including a sequence number relating to the dataflow. The techniques further include determining that a first condition defined in terms of a transition parameter of the agreed one or more roaming conditions is met, and, based on the determining, transitioning from providing the first dataflow from the first infrastructure entity to the client entity to providing the first data flow from the second infrastructure entity to the client entity.