## 2 Background and Related Works
### Related Works
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Research** & **Deployment Scenario** & **QoS Parameters** & **Limitation** \\ \hline Evaluation of Zigbee & & & Only focused on throughput and delay; real-world networking performance might vary from simulation; encrypted communication is not considered. \\ \hline Data transmission & & & Other QoS parameters, such as throughput, link quality, latency, and power consumption were not considered; encrypted communication was not considered. \\ performance analysis with Xbee Pro 2B [32] & Indoor and outdoor & Transmission range & and power consumption were not considered; encrypted communication was not considered. \\ \hline Zigbee performance & & & Comparative performance of encrypted communication and variations of deployment scenarios were not addressed. \\ analysis in Various Environments [19] & Indoor LOS and NLOS & Delay, throughput, packet loss & Comparative performance of encrypted communication and variations of deployment scenarios were not addressed. \\ \hline Comparative study of Zigbee topologies [41] & Simulation & Latency, throughput, packet loss, and energy consumption & Did not consider encrypted communication. \\ \hline Performance Evaluation of Zigbee [33] & Simulation & Delay, power consumption & Parameters, such as throughput, link quality, and data encryption were not considered. \\ \hline Analysis of Zigbee data & - & Latency, packet loss, throughput & RSSI, energy consumption, data encryption, and NLoS scenario were not considered. \\ \hline Performance evaluation of & & Throughput, round trip time, RSSI, routing recovery time & Energy consumption, data encryption, and different deployment scenarios were not considered. \\ mesh [35] & & & deployment scenarios were not considered. \\ \hline Performance of Zigbee & & & Based on simulation, which might differ from the deployed network performance. \\ network topologies [42] & Simulation & & \\  & & security & \\ \hline Performance analysis of Zigbee large scale & Simulation & Latency, throughput and other QoS parameters. \\ network [36] & & & \\ \hline Performance analysis of Zigbee WSN [37] & Simulation & Throughput, delay, data traffic & Did not consider other performance metrics, such as RSSI and power consumption. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of the research focus, QoS metrics, and limitations of the discussed works. Most of these performance analyses are based on simulations whereas the real-world performance with the deployed network might significantly vary from the simulated results. Some of the research works are conducted in the indoor environment but those did not analyze how the performance might vary in the outdoor scenarios. None of these discussed research works analyzed the performance effects of encrypted communication even though it may significantly hamper the throughput, latency, and network lifetime. Thus, this research work provides a comprehensive analysis of Zigbee considering both indoor and outdoor environments in terms of PDR, energy consumption, network lifetime, RSSI, latency, and throughput. Moreover, it also analyzes how the performance varies due to the data encryption in terms of these mentioned metrics, which would help to fill the void in this research area and help to find the most optimized configuration according to the deployment scenario.