## 6 Opportunities and Future Research Directions
### Scalability  
Poor scalability can result in poor network performance. Presently, the majority of the information about the scalability of LoRa technology is commercial in nature and focuses on the best case scenario [107]. Thus, in order to properly analyze the performance levels of such networks in huge networks, it is necessary to have realistic models available. It is possible to achieve network scalability by reducing the amount of sent packets per node per day or increasing the number of gateways when the end device population expands rapidly, such as in dense installations. LoRa and LoRaWAN configuration parameters such as the SF, CF, transmission power, BW, CR, and DR directly affect the scalability of the network, which in turn impacts the generated traffic and energy resources [108]. Therefore, improving network scalability will optimize traffic, conserve energy, and extend the battery life of edge devices, which are three important goals [109]. This is because energy efficiency and data traffic are the total data transmissions from the sensor board to the gateway that have an effect on the performance [110]. Consequently, there is a real need to develop a new data-gathering procedure for LoRaWAN to cope with scalability issues in large-scale deployment scenarios [111; 112]. That will positively affect energy conservation and play a significant role in improving LoRaWAN network scalability.  
There are several metrics directly related to LoRaWAN network scalability. Thus, simulation-based performance evaluation for the proposed approaches needs to be conducted, depending on several scalability-related metrics such as energy consumption, PDR, throughput, coverage, and latency. Relying exclusively on simulations has long been recognized as one of the key pitfalls of research on wireless networks due to the typical oversimplifying assumptions of simulation models. Therefore, any simulation results for future improvements in LoRaWAN scalability need to and will be complemented with real experimentation for the proposed approaches using a LoRaWAN testbed for validation purposes. Most of the existing studies were conducted in a laboratory or limited outdoor areas. The results of the experiments, while proving that the proposed work was effective, are insufficient compared with real deployment environments. Therefore, it is necessary to further verify the reliability and scalability of the proposed work by deploying it in a real and large-scale environment. In [105], it outperformed the typical methods when the connectivity was good, but it functioned in a comparable manner when deployed over broad areas. The improvement over the benchmark solutions being independent of the channel model used was also demonstrated (no shadowing, uncorrelated, and correlated shadowing). A fog-based architecture was also demonstrated to be viable, which has the advantage of reducing the end-to-end latency by a factor of two. The limitation of this work is that the study was limited, and the proposed solutions were ordinary. The purpose of the research in [113] was to obtain better knowledge on how to optimize competition-based channel access mechanisms at the MAC layer for LoRa and LPWAN radio technology by conducting extensive tests on the LoRa channel activity detection and capture effect feature.