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A master's thesis from Aalborg University
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Enhanced Wi-Fi 6 Wireless Communication Systems for Industrial Use Cases Requiring Mobility

Translated title

Optimerede Wi-Fi 6 Trådløse Kommunikationssystemer for Industrielle Brugsscenarier med Mobilitet

Author

Term

4. Semester

Publication year

2021

Abstract

Industry 4.0 and mobile IIoT devices require wireless communication with low latency and high reliability. This thesis examines how far Wi‑Fi (IEEE 802.11) can be pushed in industrial settings with mobility and proposes methods to improve performance with a focus on handovers. In a realistic industrial testbed using commercial enterprise Wi‑Fi, an autonomous mobile robot, and custom measurement software, latency, packet error rate (PER), RSSI, and connection state were collected with 100,000 samples per configuration to assess the 99.9th‑percentile latency. Results show handovers are the dominant source of delay, raising the 99.9th percentile from 63 ms to 297 ms under background traffic. Standardized enhancements such as IEEE 802.11r (pre‑authentication) and reducing scan channels during roaming lowered this to 174 ms, while single‑frequency deployments across access points increased latency and roughly doubled PER compared to dedicated channels. To fully mitigate handover effects, a radio‑aware transport‑layer multi‑connectivity solution with two Wi‑Fi interfaces, a packet scheduler, and a mobility coordinator was designed to duplicate traffic or select the interface based on signal quality. This network‑agnostic approach achieved 77 ms at the 99.9th percentile—a 74% reduction versus non‑optimized Wi‑Fi—thereby better supporting time‑sensitive industrial applications.

Industrie 4.0 og mobile IIoT-enheder stiller skærpede krav til trådløs kommunikation, især mht. lav latenstid og høj pålidelighed. Denne afhandling undersøger, hvor langt Wi‑Fi (IEEE 802.11) kan strækkes i industrielle miljøer med mobilitet, og udvikler metoder til at forbedre ydelsen med fokus på handover. I et realistisk industrielt setup med kommercielt enterprise‑Wi‑Fi, en autonom mobil robot og specialudviklet målesoftware blev latenstid, paketfejlrate (PER), RSSI og forbindelsestilstand målt med 100.000 prøver pr. konfiguration for at analysere 99,9%-percentilen. Resultaterne viser, at handover er den største årsag til høje latenser og øger 99,9%-percentilen fra 63 ms til 297 ms under baggrundstrafik. Standardiserede forbedringer som IEEE 802.11r (pre‑authentication) og færre scannede kanaler under roaming reducerede percentilen til 174 ms, mens enkelkanals‑udrulninger på tværs af access points forøgede latenstiden og omtrent fordoblede PER i forhold til dedikerede kanaler. For fuldt at afbøde handover‑effekter blev der designet en radiofølsom multi‑konnektivitetsløsning på transportlaget med to Wi‑Fi‑interfaces, en pakkeskeduler og en mobilitetskoordinator, der enten duplicerer trafik eller vælger interface efter signalstyrke. Denne netværksagnostiske tilgang opnåede 77 ms ved 99,9%-percentilen – en reduktion på 74% i forhold til ikke‑optimeret Wi‑Fi – og kan dermed bedre understøtte tidskritiske industrielle applikationer.

[This apstract has been generated with the help of AI directly from the project full text]