## 7 Conclusions  
This paper has successfully achieved its objective of evaluating the performance and limitations of Wi-Fi, across multiple generations of IEEE 802.11 standards, from Wi-Fi 4 (IEEE 802.11n) to early adoptions of Wi-Fi 7 (IEEE 802.11 be). To accomplish this, we deployed a comprehensive testbed in three distinct environments (residential, laboratory, and industrial) and tested six representative Wi-Fi configurations, each defined by a specific combination of frequency band, channel bandwidth, and IEEE 802.11 standard. All experiments were conducted under consistent conditions to simulate practical deployments, and we analysed the spectrum occupancy in each band to account for interference while measuring network latency and throughput. Experimental results show that Wi-Fi 6/6E (IEEE 802.11 ax) consistently outperforms earlier standards across diverse environments. Configurations with wider bandwidths, such as Wi-Fi 6 with 160 MHz channels, deliver up to 20% higher throughput at short and medium ranges compared to Wi-Fi 4 and 5, maintaining performance even under moderate interference. Wi-Fi 7, despite its theoretical advantages, exhibited throughput up to 10% lower than Wi-Fi 6 in some cases, suggesting current implementations are not yet fully optimised. Latency improvements are also evident: Wi-Fi 6 reduces delays by approximately 15% compared to Wi-Fi 5 and also offers more stable performance suitable for time-critical applications. However, in high-traffic environments, latency remains variable due to the limitations of contention-based access. Interference impacts remain significant, with latency and throughput fluctuating by up to 30% between congested and low-traffic scenarios. Even within a single band, channel performance may differ by up to 20%, and wider channels, while boosting throughput, show increased sensitivity to interference. This underscores the need for strategic spectrum and channel selection tailored to deployment conditions and reliability requirements. Despite these limitations, the performance levels achieved by Wi-Fi 6 and Wi-Fi 7 are acceptable for many industrial applications, particularly those related to digitalisation and non-critical monitoring. However, their suitability for latency-critical control tasks is still limited due to the inherent unpredictability of contention-based access mechanisms. One promising development in this context is the introduction of Resource Units (RUs), which are already part of the IEEE 802.11 ax standard. These elements provide a finer granularity for spectrum allocation, enabling better scheduling and control of medium access. Although the standard does not yet define a complete framework for their deterministic use, RUs represent a key foundation for reducing internal contention and enhancing temporal predictability in future industrial Wi-Fi deployments. Conceptualization, V.S.-P.; methodology, F.O.-S. and L.M.B.-A. ; investigation, L.M.B.-A., F.O.-S., D.L.-G., V.S.-P., T.A.-A. and J.S.-B. ; software, L.M.B.-A., F.O.-S. and D.L.-G.; validation, V.S.-P., J.S.-B. and T.A.-A. ; writing--original draft preparation, L.M.B.-A., D.L.-G., and V.S.-P.; writing--review and editing, L.M.B.-A., F.O.-S., T.A.-A. and J.S.-B. ; supervision, V.S.-P. and J.S.-B. All authors have read and agreed to the published version of the manuscript. The research leading to these results has been funded by the Horizon Europe Framework Programme of the European Commission under Grant Agreement No. 101058589 \"AI Powered human-centred Robot Interactions for Smart Manufacturing (AI-PRISM), and by Evolution of the radio access network towards 6G for massive and low-latency services\" funded by ERDF A way of making Europe and Ministerio de Ciencia, Innovacion y Universidades of Spain MCINAEI10.13039/501100011033 under Grant no. PID2021-123168 NB-100, and includes participations as part of the non-economic activity plan funded for the 2025 annuity by IVACE+. **Data Availability Statement:** The data supporting the findings of this study are available within the article.