# Reliable Fault Tolerant-Based Multipath Routing Model for Industrial Wireless Control Systems
## 1 Introduction
Fault tolerance is simply a matter of evaluating all possible abnormal states in a timely  
Figure 1: WirelessHART mesh network structure. manner and devising a fault-tolerant control strategy. The purpose is to adapt to a wide variety of network abnormalities and deliver a highly trusted computing solution once network failures or mistakes have been recognized. Fault tolerance technology plays an essential role in enhancing the wireless sensor network reliability and robustness [18]. It is a critical technical challenge that must be resolved and has developed into a significant research field in wireless sensor networks [19]. Multipath routing is regarded to be an efficient method of enhancing fault tolerance and transmission reliability [20]. The purpose of multipath transmission technology, which is based on network encryption, is to transport the encrypted data across numerous pathways placed between the source and destination nodes [21]. Some of the delivered data packets at the sink node can be reassembled into the form of original packets sent by the source node. Multipath routing enhances the trade-off between multiple routes and transmission bandwidth through the technique of redundant pathways and load balancing to achieve reliable transmission and fault tolerance [22]. Additionally, the multipath routing technique takes into account minimizing the transmission delay and energy consumption balancing in wireless sensor networks [23]. As a result, the construction of multipath routing is the study's main focus in order to improve the fault tolerance and reliability of industrial wireless network. This work exhibits a new contribution of designing and developing a fault tolerance multipath routing (MPR) network model, such that the high reliability of wireless mesh networks can be realized. The main aims are to achieve better coverage and connectivity via fewer routers and pathways of network layout by utilizing a network planning algorithm. The MPR model structure is composed of three different pathways that have different lengths. The shortest path always has a faster data transmission rate given that all nodes and edges are the same. The other two paths are of the same length and behave as alternative paths for the case of shortest path transmission failure. A fault model is considered to verify and evaluate the robustness of the developed MPR model and monitor the behavior of the network with the existence of link failure. The effectiveness of the developed MPR is verified using WirelessHART, stack which was implemented in the Network Simulator 2 (NS2) [24]. Consequently, the results are analyses and compared with three of the existing routing algorithms namely: Han [25], Kunzel [26], and QLRR [4] using performance criteria such as expected network lifetime (ENL), average network latency (ANL), and packet delivery ratio (PDR). The rest of this article is categorized as follows: Section 2 provides background information transmission reliability, fault tolerance, and summarizes related works regarding wireless solutions. Section 3 explains the methodology and the simulation setup. Results and discussion are explained in Section 4. Lastly, this paper is concluded in Section 5.