# Network Diffusion Algorithms and Simulators in IoT and Space IoT: A Systematic Review
## 4 Analysis
#### 4.1.1 NS-3  
Overview  
NS-3 is a widely used discrete-event network simulator designed for both research and educational applications. As an open-source platform, it enables the simulation of internet systems, making it ideal for various network scenarios, including IoT and Space IoT configurations [106]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**N** & **Year** & **New: Emulator, Simulator, or Module** & **Base Simulator** \\ \hline
[76] & 2020 & Dockemu & NS-3 \\ \hline
[77] & 2020 & xFogSim & \\ \hline
[78] & 2021 & LoRaWANSim & \\ \hline
[79] & 2021 & ROS-NetSim & NS-3 // Gazebo \\ \hline
[80] & 2021 & Extension & Cooja, Contiki \\ \hline
[81] & 2021 & IoTSim-Osmosis & \\ \hline
[82] & 2022 & NS-3 SAAS & NS-3 \\ \hline
[83] & 2022 & & \\ \hline
[84] & 2022 & & Cooja, Contiki \\ \hline
[85] & 2022 & Large-scale NB-IoT & \\ \hline
[18] & 2022 & Simulator for blockchain with IoT & \\ \hline
[86] & 2022 & Faulty IoT network simulator & \\ \hline
[87] & 2022 & ADIperf framework & \\ \hline
[88] & 2022 & FLORASAT & OMNeT++ \\ \hline
[89] & 2023 & & Cooja, Contiki \\ \hline
[90] & 2023 & Extension & NS-3 \\ \hline
[91] & 2023 & FLoRa & OMNeT++ \\ \hline
[92] & 2023 & StackNet & NS-3 \\ \hline
[93] & 2023 & Kaala 2.0 & \\ \hline
[94] & 2023 & Plot & \\ \hline
[95] & 2023 & NS-3 Docker Emulator & NS-3 \\ \hline
[96] & 2023 & & NS-2.35 \\ \hline
[97] & 2024 & Lr-WPAN, 6 LoWPAN & NS-3 \\ \hline
[98] & 2024 & NDT & NS-3 \\ \hline
[99] & 2024 & GothX & Gotham \\ \hline
[100] & 2024 & Extension & ZigBee network simulator \\ \hline
[101] & 2024 & & GI-ITM \\ \hline
[102] & 2024 & & Custom simulator (Python-based) \\ \hline
[103] & 2024 & MAPE & AFTER \\ \hline
[104] & 2024 & SWI-FEED & NS-3 \\ \hline
[1] & 2024 & UDP module extension & Cooja, Contiki \\ \hline
[105] & 2024 & & NetSim \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._Features
* Extensibility: NS-3 supports a modular architecture, allowing easy integration and extension of new protocols and models. * Realism: Provides realistic simulation models for various network protocols and technologies. * Support for IoT Protocols: Includes modules and extensions for simulating IoT-specific protocols such as LoRaWAN and NB-IoT. * Visualization Tools: Supports integration with external visualization tools, including NetAnim [107] for 2D simulation and NetSimulizer [108] for 3D simulation. These tools enhance the analysis and representation of simulation results, providing detailed insights into network behavior and performance. * Scalability: Capable of simulating large-scale network scenarios, typically involving thousands to tens of thousands of nodes and plus, high traffic loads, and diverse communication protocols. The simulation complexity increases based on node interactions, mobility models, and protocol layers, making NS-3 suitable for evaluating extensive IoT and Space IoT deployments. * Support for Multiple Programming Languages: Primarily supports C++ and provides Python bindings for ease of use. * Support for Wireless Technologies: NS-3 provides built-in support for wireless communication models, including Wi-Fi, LTE, and 5G, with ongoing research into 6G integration. It allows for the testing of routing algorithms, noise models, fault tolerance mechanisms, and packet drop rates, making it ideal for large-scale IoT simulations. Limitations
* Steep Learning Curve: Requires substantial understanding of network protocols and programming proficiency, which may be challenging for beginners. * Resource-Intensive: Large-scale simulations in NS-3 can be computationally demanding, especially when modeling networks with over 10,000 nodes, high event densities, and complex protocol stacks. These simulations typically require processing times ranging from a few minutes to several hours, depending on the scenario's complexity. For example, simulating a 6144-host network can take 11 to 27 h to advance just five seconds of simulated time [109].