Access Point Path Update for Wireless Roaming Reliability

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Solution Overview

Problem

In wireless local area networks, service packet forwarding efficiency and reliability are compromised due to changes in the forwarding path caused by roaming or switchover between active and standby Access Controllers, leading to packets not reaching mobile terminals.

Innovation Solution

An access point device obtains change information about the packet forwarding path and sends a path update packet to the forwarding device, which updates the forwarding path, ensuring that the address of the mobile terminal is correctly mapped to the new path, using ARP or RARP packets for address resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If local forwarding or tunnel forwarding is used in WLAN, then service packets can be forwarded from STA to second device, but when roaming or switchover between active and standby ACs occurs, the forwarding path changes and packets sent by second device to STA cannot reach the destination, reducing service reliability

Engineering Contradiction:
Improveservice forwarding reliabilityVSAvoidforwarding path adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by having the AP proactively detect forwarding path changes (through ARP packet monitoring or AC notifications) and send path update packets to the forwarding device before packets need to be forwarded along the new path. This advance detection and notification mechanism ensures the forwarding device's MAC address table is updated beforehand, preventing packet loss during roaming or AC switchover events.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If the forwarding device learns STA address through ARP packets from original path, then forwarding table is updated, but when path changes occur, the learned address information becomes outdated and packets cannot reach the new destination

Engineering Contradiction:
Improveforwarding address information accuracyVSAvoidpath update time delay
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent implements feedback by establishing a monitoring mechanism where the AP continuously detects changes in the forwarding path (through ARP packet analysis or notifications from AC). When a path change is detected, the AP sends a path update packet to the forwarding device, creating a feedback loop that keeps the forwarding device's address information current and synchronized with the actual network topology.

Inventive Principle:
Principle #23Feedback

3Reliability

If path update packets are sent immediately when changes occur, then service reliability is improved, but network overhead and processing complexity increase

Engineering Contradiction:
Improvepacket delivery reliabilityVSAvoidpath update mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the path update packet to serve multiple functions: it not only updates the forwarding device's MAC address table but also confirms path validity and triggers necessary state changes in the forwarding device. This multi-functional approach consolidates several operations into a single packet exchange, reducing overall system complexity while maintaining reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2725766B1Service packet forwarding and processing method and system, and access point ap
Publication Date: 2018.08.29 HUAWEI TECH CO LTD
  • EP2725766B1 patent drawingFigure 1~2
  • EP2725766B1 patent drawingFigure 3~4
  • EP2725766B1 patent drawingFigure 5~7

AI summary

Embodiments of the present invention provide a service packet forwarding and processing method and system, and an access point AP. The service forwarding and processing method according to the present invention includes: obtaining change information of a packet forwarding path of a mobile terminal STA; and sending a path update packet to a forwarding device according to the change information of the packet forwarding path of the STA, so that the forwarding device performs update processing on the forwarding path of the STA according to the path update packet. This improves service forwarding efficiency, thereby ensuring service reliability.