# Routing Protocols Performance on 6 LoWPAN IoT Networks
## 2 Related Work
### Simulation Tools  
In IoT area, simulators play a crucial role in replicating real-world scenarios using various quality of service (QoS) settings, enabling the prediction and mitigation of unexpected faults prior to actual deployment. It is imperative to ensure efficient management of heterogeneity in devices, technologies, settings, and applications, particularly considering the estimated 75 billion smart devices that will be connected by 2025 [29]. Realistic simulation outcomes require the capacity to disseminate information across many environments utilizing various technologies. Network Simulator tools are essential for network simulation in the context of computer networks. Large-scale network implementation and instantaneous router deployment might be costly and difficult. Setting up and experimenting with real-time networks, creating network protocols, and keeping an eye on multiple parameters provide challenges for researchers. Still, these simulators present a reasonably priced and effective substitute [9].  
Cooja version 2.7 is a versatile, cross-level Java simulator, that functions within Instant Contiki 3.0 and emphasizes wireless sensor network behavior. It supports protocols under 6 LoWPAN network and supports the IEEE 802.15.4 standard, which is implemented by hardware like the Texas Instrument (TI) CC2420 transceiver [30]. Emulation of hardware level motes, such as Tmote Sky, Z1 and Wireless channel models like DGRM are implemented in the simulator. Each node's radio transceiver's power condition is shown by the debugging tool TimeLine [31].  
NS-2 is an open-source, discrete-event simulator that is extensively used and well-known for its ability to simulate network settings. The final official release is NS-2.35. NS-2 offers the ability to simulate network establishment, protocol implementation, and real-time scenarios. NS-2 enables users to simulate new protocols through a scripting interface. Researchers and developers will be able to explore and validate new networking protocols for real-time analysis and generate detailed trace files for performance evaluation. Being free software, NS-2 is accessible for research, development, and practical exercises on both Linux and Windows platforms [9]. It supports a variety of IP protocols, including TCP/IP, routing; however, 6 LoWPAN was not supported. Conversely, NS-3 is an open-source device which was created to take the place of NS-2 for working with several protocols, such as the 6 LoWPAN protocol stack [31].  
NS-3, intended as a replacement for NS-2 focused on communication network research and development, in keeping with IoT goals. The latest release is NS-3.43. With optional Python bindings, the fundamental simulation is written in C++, and it is integrated with other tools such as NetAnim 3.109, PyViz 0.3.2, and Bake [30].  
As desktop software, NetSim is designed for modeling and simulating diverse network types, allowing the development of user-defined protocols and integration with software like MATLAB and SUMO [9]. The current NetSim version is 14.02 with three options i.e., Academic, Pro and Standard. Recognized as an advanced simulator, NetSim is dedicatedto protocol modeling and simulation of networks. It offers a comprehensive exploration of computer networks, covering most aspects of networks, making it a widely used tool in research [32].  
In addition to the mentioned simulators, OMNET++, Tossim, MATLAB, and SUMO are widely used in research. OMNET++, an open-source C++ simulator for communication networks, offers packet-level analysis but it is not designed particularly for 6 LoWPAN [31]. Tossim, in TinyOS, prioritizes scalability and fidelity for MicaZ motes [30]. MATLAB and Simulink support IoT system modeling with custom simulation and connectivity to platforms like ThingSpeak [9].