# Reliable Fault Tolerant-Based Multipath Routing Model for Industrial Wireless Control Systems
## 2 Literature Review
### Latest IWSN Simulation Solutions  
Network simulators are commonly used to test and evaluate networks and communication protocols. Thus, a comprehensive summary of the most relevant works about simulators utilized in the domain of IWSNs, emphasizing the simulations accuracy, is discussed in this section. We studied the amount of complexity applied in the simulations (that enables more detailed simulations) and the measures employed in the simulator assessment. For instance, [PERSON] et al. in their study [37] presented a WirelessHART implementation in OMNET++ for the purpose of conducting security experiments in the network. The model implemented the Network Manager as well as the entire protocol stack using the physical layer features of InetManet [38]. This demonstrated that it is possible to implement a complete IWSN protocol stack on a simulator. [PERSON] et al. [39] adapted a commonly used industrial process model (Process Control Challenge Problem, known as Tennessee Eastman [40]) by incorporating wireless communication links in the model between process control, actuators, and sensors. The findings of the simulation demonstrate that the process may be carried out via wireless communication links. This work evaluated the impact of different wireless layouts and setups on the process operation. OMNET++ was the simulator utilized, while models from the MiXiM and INET frameworks are utilized for the wireless channel template and the address resolution protocol (ARP), respectively. The WirelessHART protocol is used in the simulation and concentrates on the layers of Medium Access Control (MAC) and Physical (PHY). The authors provided the source code online, which can be found at [41]. The process variables deviation from their nominal values, as well as the estimated period for which the plant can function normally, are the performance metrics that are being evaluated. During simulation, a modification of access points positions as well as the packet error rate of the RF communications was performed. However, neither the functionalities of the WirelessHART gateway nor a complete stack of WirelessHART protocol were implemented in the simulator. The authors in [42] proposed simulated ZigBee, WirelessHART and ISA100.11a networks using Castalia and Pymote. The performance metrics evaluated in their work are device energy consumption, the number of transmitted packets, and throughput. The widely available generic models were employed during simulations (i.e., the MAC layer and Physical layer of IEEE 802.15.4 models for the simulations of ISA100.11a and throughput Test generic application). Neither the functionalities of WirelessHART and ISA100.11a gateway nor the communication stack of all layers has been implemented in this work. Meanwhile, [PERSON] et al. in [43] proposed an ISA100.11a model for ns-3 that implements a simplified application layer as well as the standard's data link and physical layers. The source code of this work is available online at [44]. On the other hand, the simulator proposed by authors in [45] is a cycle-accurate type which is used for WSNs and it is called Avrora. Scalability in real-time is up to as many as 25 nodes, which it can handle. Unlike ATEMU [46], Avrora aims for highly accurate timing with improved performance. This is achieved by extracting fine granularity parallelism within the WSN simulation. In [47], the authors proposed an energy consumption based mathematical model for wireless sensor nodes. It takes into account the communications, acquisition, and processing of the energy consumption. The study in [48] discussed the simulation significance of the impact of CPU load on the IWSN and the benefits of doing so. For precise simulation of wireless sensor nodes, the ns-2 simulator [49] has been integrated with the RTSim [50] program. The evaluation is done based on the IEEE 802.15.4 communication standard [51]. The research work in [52] proposed an algorithm to plan the network structure, which determines the routes that are necessary to be deployed.