# Reliable Fault Tolerant-Based Multipath Routing Model for Industrial Wireless Control Systems
## 2 Literature Review
### Latest IWSN Simulation Solutions
However, validating the network latency issues and the packet loss mitigation techniques were not considered. The implementation of WirelessHART and ISA100.11a in a refinery was discussed in [53]. A new simulator, known as the RF Propagation Simulator (RFSim) has been developed to aid with the implementation process. It estimates the quality of an RF signal in the vicinity of a manufacturing facility or a commercial establishment. The findings of the simulation were compared to those obtained from on-site measurements, and they appeared promising. The authors pointed out that the majority of work published on sensor network implementation is limited to a 1D or 2D environment, while considering 3D environments as an open issue at this time. In [51], an enhanced industrial WSN model was proposed and evaluated. The model integrated an ns-3 network simulator with the functional communication stack of the ISA100.11a standard. The simulation accuracy was validated using different scenarios such as node-in-the-loop and hardware-in-the-loop (HIL). A full stack of WirelessHART and gateway implementation is proposed in [24] which was done on the ns-2 simulator [49]. To ensure that the model is accurate, the authors put up identical networks both on real hardware and in the simulator. The performance of both real and simulated networks was compared based on the network's energy consumption,real-time packet transfer, throughput and communication scheduling, and network reliability (i.e., received signal level average and ratio of failed transmission). The efficiency of management was measured in terms of performance delay and overhead during the procedures of service request and joining. The performance of the simulator in wireless mesh networks is also evaluated with particular attention paid to the network's responsiveness in the event of link and node failure. Furthermore, three different lossy networks were evaluated in terms of packet delivery rate. These assessments have shown that the real network results have common sense when compared to the simulated results. Hence, the versatility of the suggested model made it applicable in a variety of situations and scenarios. Studies have made it possible to indulge various aspects of hardware in simulation scenarios in order to improve the accuracy of the simulation results. This is referred to as hardware-in-the-loop. Authors in [54] integrated physical wireless nodes with the TSSIM simulator at the level of radio communication. The proposed work showed the viability of a WSN comprising both physical and simulated nodes. This was accomplished through the use of a physical Dual Base Stations pair as a bridge linking simulated and physical environments. Hence, a real-time simulation is achieved. Although the technology enables communication between simulation environment node and real environment nodes, the position and number of real nodes are bounded by the linking devices capabilities. Studies in [55,56] stated that the easy way to deploy a WSN in a certain layout is to evaluate the WSN software using software-in-the-loop simulation method. This is achieved by the integration of the software on the installed wireless sensor network with a sensor device and simulated environment. A simulation of radio hardware is demonstrated in [57], which shows how it can be integrated into the simulation. Physical phenomena and real hardware are used to implement physical Medium and the Physical Layer of IEEE 802.15.4, respectively, in this Radio-in-the-Loop (RIL) method. Software implements communication layers above these, comprising the MAC layer of IEEE 802.15.4. As a result, the experimental results are more realistic than the pure simulation results. The OMNeT++ network simulator was employed in this work, and the interface to the hardware is relying on the PcapNG data format and the inter-process communication known as Linux/Unix. The radio utilized is an IEEE 802.15.4 compatible ATmega128 RFA1 operating a customized Contiki OS application [58].