## 7 Conclusions and Future Work  
In this paper, real-world measurements were captured to evaluate the performance of a live multi-gateway LoRaWAN 868 MHz and interference across indoor and outdoor localities. There were packet delivery success rates of 99.95% and 95.7% for the indoor site and outdoor, respectively, along with the achievable range. Performance parameters of the LoRaWAN technology reported here show that LoRaWAN technology has a place in enabling the IoT. Only a small portion of the overall functionality and performance of the LoRaWAN has been evaluated to date. However, new sites and networks are coming online, so further research is required to fully understand LoRaWAN performance for different quality use cases and scenarios. The LoRaWAN ecosystem is constantly growing with a range of consumer devices now available, so the primary constraint on the uptake of the technology is the demand for the service that LoRaWAN provides. This demand grows as building owners implement energy monitoring and energy management while the smart meter market continues to develop. Undoubtedly, other IoT sensing, and control opportunities are developing. Although LoRaWAN is only one of the potential IoT enablers, the combination of performance and developing ecosystem means that it will play some significant role in the roll-out of the IoT. The coverage of LoRaWAN, which is being deployed to facilitate wireless connectivity for the IoT, is likely to be affected by the interference from other sources, including other sub-GHz technologies and other LoRaWAN networks.  
The study of interference in Glasgow CBD has shown a significant signal activity in the 868 MHz ISM band. The core LoRa 868.0-868.6 MHz sub-band for uplink was occupied with signals stronger than \(-97\) dBm with the higher and lower probability of interference of \(97.3\%\) and \(0\%\) at GCU and Buchanan Bus station, respectively. The potential to interference in the LoRa 869.4-869.65 MHz sub-band for downlink is higher at Rottenrow Garden and Kelvingrove Park with the probability of interference at \(54\%\) and \(49.7\%\) respectively. The comparison of interference probability reported for LoRa core channels in Aalborg city, Denmark, and Glasgow, the UK, four years ago shows that interference in the 868 MHz ISM band is increase with growth of LPWAN deployment.  
In the future, lessons learned from Glasgow measurements and a detailed measurement dataset for 868.0-868.6 MHz will be combined to model interference for 868 MHz ISM band in Glasgow city. The ongoing deployment of long-range sub-GHz technologies will make the 868 MHz ISM frequency band heavily contested.  
Original data collection, E.H. and A.J.W.\({}_{2}\) conceptualisation approach, proofreading and funding for original research data, H.L.; proofreading and validation of technical approach, A.-U.-H.Q. and R.M.G. All authors have read and agreed to the published version of the manuscript.  
This research received scholarship from the British Commonwealth PhD Scholarship scheme.  
Not applicable.  
Data Availability Statement: Data is contained within the article.  
The authors wish to acknowledge the British Commonwealth PhD Scholarship scheme for their financial support for this project.  
The authors declare no conflict of interest.