Stationary Client Roaming Prevention in Overlapping AP Coverage

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Solution Overview

Problem

In wireless networks with overlapping access point coverage areas, stationary client devices repeatedly switch between access points, causing unnecessary communication and processing overhead, as the signal strengths of overlapping access points are similar, leading to little to no signal strength improvement from roaming.

Innovation Solution

The wireless network detects stationary client devices in overlap areas and assigns a preferred access point, preventing them from roaming by instructing other access points to avoid connecting with the client device, thus reducing unnecessary overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple access points are deployed to broaden coverage and improve signal strength, then coverage area and signal quality are improved, but repeated roaming of stationary clients between overlapping APs causes increased network overhead

Engineering Contradiction:
Improvecoverage areaVSAvoidnetwork overhead
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The system performs preliminary detection of stationary client devices in overlap areas before roaming occurs. By identifying stationary clients ahead of time and assigning them to a primary AP, the system prevents the repeated roaming that would otherwise generate excessive network overhead, thus resolving the contradiction between coverage breadth and network efficiency

Inventive Principle:
Principle #10Preliminary action

2Strength

If access points are deployed with overlapping coverage to ensure adequate signal strength, then signal quality is improved, but stationary clients experience repeated roaming between APs with little signal improvement

Engineering Contradiction:
Improvesignal strengthVSAvoidnetwork efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The system applies different roaming behaviors to different client types: stationary clients are assigned to a primary AP and prevented from roaming, while mobile clients retain normal roaming capabilities. This localized differentiation resolves the contradiction by optimizing for stationary clients' stability without compromising mobile clients' mobility, thereby improving overall network efficiency while maintaining signal quality

Inventive Principle:
Principle #3Local quality

3Loss of energy

If access points coordinate to assign clients to specific APs in overlap areas, then repeated roaming is reduced, but detection and management complexity increases

Engineering Contradiction:
Improvenetwork overheadVSAvoidAP coordination complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system enables APs to autonomously detect stationary clients in overlap areas and make assignment decisions without requiring complex centralized coordination. Each AP can independently identify stationary clients and manage their associations, significantly reducing the coordination overhead while still achieving the benefit of reduced repeated roaming

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3565312B1Roam prevention for stationary client devices in areas of access point coverage overlap
Publication Date: 2021.05.26 HEWLETT PACKARD ENTERPRISE DEV LP
  • EP3565312B1 patent drawingFigure 1
  • EP3565312B1 patent drawingFigure 2
  • EP3565312B1 patent drawingFigure 3

AI summary

An example of controlling a network of wireless access points (APs) to detect that a client device associated with the network is stationary in an AP-overlap area, and in response to the detection that the client device is stationary in the AP-overlap area, assigning one of the APs to be a preferred AP for the client device. The APs are to avoid connecting with any client devices that have been assigned another AP as a preferred AP. Thus, the stationary client device in the overlap area may be prevented from undesired roaming.