# Internet of Things and Its Applications: A Comprehensive Survey
## 5 IoT Applications
### Commercial Applications  
In recent times, the IoT commercial applications have been greatly expanded. In a study conducted by [PERSON] [126], a prototype-driven technique used to mechanize the QoS-aware facility structure involving real-time control was designed. The author mentioned the violation of the service-level agreements (SLAs) as a major worry. Therefore, the SLAs were plotted to combine the Petri net model with the UML QoS model by indicating users. An analysis of the Discrete Event System (DES) is essential and showed that the suggested approach could deliver a combined facility to be employed in the Petri net model. It created a review for evaluating the implementation cost-effectively, in order to satisfy QoS; however, the scalability was not considered in the research. In another research work performed by [PERSON] and [PERSON] [127], the design of semantic maintenance supplying for smart devices is presented. The primary objective was to provide a web-based smart device service through numerous conventional Application Programming Interfaces (API) concerning their constraints, including assets (ROM, RAM, and CPU), low-speed transmission paths, and energy-efficient microcontrollers. It was evaluated in several situations by samples and functions on the web simulated by Contiki Cooja \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Reference** & **Focus Area** & \multicolumn{2}{c}{**Application**} & **Protocol** & **Device** \\ \hline \multirow{3}{*}{[113]} & Semantic-aware mobile & \multicolumn{2}{c}{Service composition in} & & \\  & crowd-sensing & \multicolumn{2}{c}{smart city} & & \\ \hline \multirow{3}{*}{[114]} & \multirow{3}{*}{Digital forensics} & • Smart cities & \multirow{3}{*}{Cellular} & \multirow{3}{*}{Smartphone} \\  & • Smart homes & & & and laptop \\  & • & Wearables & & \\  & & smart grids & & \\ \hline \multirow{3}{*}{[115]} & Location finding along with the & • Energy informing & \multirow{3}{*}{LoRa} & \multirow{3}{*}{Sensor device} \\  & updated location configuration & • Log tracking & & inside an \\  & features & • Monitoring & & 'umbrella tube’ \\ \hline \multirow{3}{*}{[116]} & \multirow{3}{*}{Big Data processing} & \multirow{3}{*}{Smart home} & Bluetooth low & \multirow{3}{*}{MapReduce} \\  & & & energy (BLE) & \\ \hline \multirow{3}{*}{[117]} & Analyze and predict the & \multirow{3}{*}{Smart home} & \multirow{3}{*}{LoRa} & Remote device \\  & performance of applications & & & and server \\  & used in scalable platforms & & & \\ \hline \multirow{3}{*}{[118]} & Context-aware service & \multirow{3}{*}{Smart home} & \multirow{3}{*}{wEASEL} & \multirow{3}{*}{Smartphone} \\  & composition & & & \\ \hline \multirow{3}{*}{[119]} & Cloud computing service & \multirow{3}{*}{Vehicular monitoring} & \multirow{3}{*}{OIDM2M} & \\  & composition & & & \\ \hline \multirow{3}{*}{[120]} & QoS service composition & \multirow{3}{*}{Smart home} & Bayesian networks & \multirow{3}{*}{Smart devices} \\  & & & & \\ \hline \multirow{3}{*}{[121]} & Manage heterogeneous data & \multirow{3}{*}{Weather systems} & ITS & \\  & streams & & & \\ \hline \multirow{3}{*}{[122, 123]} & Traffic management and & \multirow{3}{*}{Street parking system} & \multirow{3}{*}{CoAP} & \multirow{3}{*}{WSN Devices} \\  & dynamic resource caching & & & \\ \cline{1-1}  & management & & & \\ \hline \multirow{3}{*}{[124]} & Real-time low power routing & \multirow{3}{*}{Smart city} & RPL & \\ \cline{1-1}  & protocol & & & 3G/4G Cellular \\ \hline \multirow{3}{*}{[125]} & Fog-based architecture to & \multirow{3}{*}{WiFi} & WiFi \\ \cline{1-1}  & manage IoT applications & & ZigBee & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: IoT smart city applications. (simulator). The outcome of this research is represented in the improvement of IoT applications on the web and development of essential elements, including the security, reliability, and scalability for service provisioning. However, this study did not present the differences in a comparison with similar available studies. [PERSON] et al.