Intra-WLAN Mobility Reporting to 3GPP RAN

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Solution Overview

Problem

The interworking mechanisms between 3GPP and WLAN networks can result in conflicts, leading to undesirable side effects such as ping-ponging between WLAN access points, as the 3GPP RAN may not be aware of intra-WLAN mobility events, causing the UE to oscillate between network nodes.

Innovation Solution

The wireless device receives an identification of network nodes from the 3GPP network and reports mobility events to the 3GPP RAN when moving to a new WLAN access point not included in the initial list, allowing the 3GPP RAN to update its knowledge and avoid conflicts by adding or removing node identifiers, thus preventing ping-ponging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the 3GPP RAN provides a list of WLAN identifiers to the UE for traffic steering, then operator control over access selection is improved, but the UE cannot discover or report new WLAN access points that are not in the initial list, causing the 3GPP RAN to remain unaware of intra-WLAN mobility events

Engineering Contradiction:
Improve3GPP RAN awareness of WLAN access pointsVSAvoidUE reporting mechanism complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the UE monitors WLAN access point changes and reports them back to the 3GPP RAN. When the UE detects that it has moved to a new WLAN access point not in the original list, it sends a report containing the new WLAN identifier to the 3GPP RAN, which then updates its record. This closed-loop feedback ensures the 3GPP RAN maintains current awareness of the WLAN access points the UE is using without requiring continuous UE initialization with updated lists.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The UE autonomously monitors its own WLAN connectivity status and independently determines when to report new access points. The UE performs self-service by comparing its current WLAN association against the provided list and initiating reports only when necessary, reducing unnecessary signaling while ensuring the 3GPP RAN is informed of relevant changes.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If the 3GPP RAN continuously updates the UE with new WLAN identifiers, then the UE can discover all available WLANs, but signaling overhead and network complexity increase significantly

Engineering Contradiction:
ImproveUE ability to discover WLANsVSAvoidSignaling and network management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The 3GPP RAN performs preliminary action by providing an initial list of WLAN identifiers to the UE at the start of interworking. This preliminary provision allows the UE to immediately begin traffic steering without requiring continuous updates. The RAN only performs additional actions when the UE reports new access points, reducing overall signaling compared to continuous update mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of providing the complete and ever-changing set of all possible WLAN identifiers, the system uses partial action by providing an initial subset that is sufficient for most scenarios. The UE supplements this partial information through its own monitoring and reporting capabilities when new access points are encountered, achieving complete adaptability without the overhead of comprehensive continuous provisioning.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If the UE applies interworking mechanisms to all possible WLANs, then traffic steering flexibility is maximized, but conflicts arise when steering to WLANs not authorized by the operator

Engineering Contradiction:
ImproveTraffic steering flexibilityVSAvoidOperator control reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the WLAN identifier space into two categories: operator-authenticated WLANs (provided in the initial list) and discovered WLANs (reported by the UE). The 3GPP RAN applies different handling rules to each segment. For authenticated WLANs, the RAN maintains full control and can enforce steering policies. For discovered WLANs, the RAN updates its knowledge base and allows flexible steering while maintaining awareness. This segmentation resolves the conflict between flexibility and control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The UE acts as an intermediary between the WLAN access points and the 3GPP RAN. It receives the authenticated list from the RAN, discovers additional access points through its own monitoring, and reports them back to the RAN. This intermediary role allows the system to combine operator-controlled authentication with UE-driven discovery, achieving both reliability and flexibility without direct conflict.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3254496B1Method and apparatuses for reporting intra-WLAN mobility to a 3GPP network
Publication Date: 2019.12.11 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3254496B1 patent drawingFigure 1
  • EP3254496B1 patent drawingFigure 2
  • EP3254496B1 patent drawingFigure 3

AI summary

According to some embodiments, a method in a wireless device operable in a first wireless communication network and a second wireless communication network comprises receiving, from the first wireless communication network, an identification of network nodes of the second wireless communication network. The network nodes of the second wireless communication network are operable to process traffic for the wireless device. The method further comprises receiving an instruction from the second wireless communication network to move traffic from a first network node of the second wireless communication network to a second network node of the second wireless communication network. The first network node is one of the identified one or more network nodes of the second wireless communication network. The method also comprises determining that an identification of the second network node is not included in the received identification of one or more network nodes of the second wireless communication network.