## 4 LoRaWAN Issues and Recent Solutions
### Network Scalability  
A number of studies focused on LoRaWAN network scalability. The scalability challenge of LoRaWAN installations occurs owing to the high number of end device request ACKs and the duty cycle constraint that the gateway must comply with. A lack of scalability may wreak havoc on the current scalability information, which is mostly commercial and assumes the best case scenario. In [41], the authors suggest adding more gateways to enhance LoRa scalability. The authors created a LoRa simulator, dubbed LoRaSim, based on the Python programming language. They terminated the network with a single gateway, which does not scale well with standard transmissions, while networks that automatically adjust the transmission parameters or have several gateways may scale better. The finding of the study is that LoRa network scalability increases if the ToA is minimized by the optimal configuration parameters as well. However, this model associates over-value attenuation in open space for LoRa's signals. It needs to be evaluated on-site, as the majority of the coverage area includes conventional connections, which have been defined as connections to dynamic time links. Although the use of various gateways outperforms the present findings, the efficiency will further be improved by the optical location of the gateways in proportion to the application community. In [45], the authors describe the results of LoRaWAN scalability research in which they created a mathematical model of the transmission process in order to analyze the scalability of LoRaWAN networks. After much deliberation, they came to the conclusion that the network's capacity was only 1% of 51 byte frames per second. This amount of capacity equates to 5000 motes, each of which can transmit two messages each day on average. This capacity is reserved for uplink traffic that has been confirmed. In [46], a different method was used by the authors, who examined the scalability of a LoRaWAN network in which the end nodes broadcast messages regularly, regardless of the radio duty cycle. In their claim, the authors said that such an evaluation provided a lower constraint on the maximum number of nodes that could be serviced by a single portal. Another example of scalability research was carried out using a simulation model and the results of measurements with actual nodes. However, the measurements were not carried out in an interference-free environment as in the previous study. Only three particular parameter sets for the nodes were taken into consideration by the authors. In [47], a scalability study for LoRaWAN was carried out using a stochastic geometry framework, and the results were presented. The authors demonstrated that the likelihood of coverage decreased exponentially with the rise in the number of end devices. The theoretical capability of LoRaWAN in terms of scalability and node throughput has been investigated in a number of research projects [48]. The detrimental impacts of interference were examined in densely crowded LoRaWAN cells. The authors have investigated several difficulties relating to co-distribution which, in particular, damages the scalability of LoRaWAN networks. All these studies proved that LoRaWAN networks should be configured properly to connect a great number of end devices. The authors of [49] contrasted LoRaWAN with other communication technologies. LoRaWAN has benefits in its capacity for open standards, integrated security, GPS-free geolocation, long-distance communication, low energy consumption, and private deployment choices. In addition, the lower data rate, duty cycle restrictions, and benefits limit LoRaWAN networks in real-time applications. LoRaWAN is ideally suited to circumstances in which data transfers are infrequent (several packets a day), and the payload size is about 10-50 bytes. Smart cities, intelligent grids, intelligent farming, and remote monitoring systems are the areas of optimum use for LoRaWAN.