# Analysis of Fault Classifiers to Detect the Faults and Node Failures in a Wireless Sensor Network
Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; [EMAIL_ADDRESS] (S.A.); [EMAIL_ADDRESS] (M.M.) Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; [EMAIL_ADDRESS] (S.A.); [EMAIL_ADDRESS] (M.M.) Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; [EMAIL_ADDRESS] (S.A.); [EMAIL_ADDRESS] (M.M.) Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; [EMAIL_ADDRESS] (S.A.); [EMAIL_ADDRESS] (M.M.) Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; [EMAIL_ADDRESS] (S.A.); [EMAIL_ADDRESS] (M.M.) Mashael  
5 Department of Software Engineering, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia; sadharbi@ksu. into an electrical signal for further processing. In WSN, the sensing unit performs the functionality of a transducer with the help of tiny and powerful sensors. The WSNs nodes are deployed in environments such as forests, rivers, and mountains to detect or sense various atmospheric parameters such as temperature, humidity, fire, and pressure. The information collected by the sensor nodes is converted as an electrical signal from signals such as sound, light, etc. by the transducers. Then, the electrical analog signal has to be converted into a digital signal as binary information. The sensed and converted binary information is passed to the next stage, where all the calculations and processing are carried out in WSNs. This processing unit has limited memory and hence, it will forward the binary information to the next sensor node, or it will process itself based on the requirement. The processing unit has the control of a sensing module with limited capacities. The important and essential part of the sensor unit is the data communication module, which contains the transceiver circuit that will perform both transmitter and receiver functions for the data exchange. It is the responsibility of the communication module to ensure all the information passes through the routing protocols [2] and data communications. The components of the sensing module, processing module and communication module are connected in a Printed Circuit Board (PCB), which is made as small as possible for power constraints. This connected module is referred to as a sensor node. Figure 1 illustrates an overview of the sensor node architecture. The sensor nodes sense parameters, such as pressure or temperature, at regular intervals. The WSNs are used in a hazardous environment, as they work in unmonitored fashions, and they are also deployed in extreme environmental conditions. This scenario leads the WSNs to be highly vulnerable to failures. The failures in WSNs are as follows,  
* Software failures, which lead to malfunction of sensor nodes;
* Hardware failures occur, due to a sensor fault or a signal conditioning circuit fault;
* Communication failures are due to a fault on wireless antenna circuits or wireless protocols. Based on the sensed data, the faults are classified [3] into different categories as mentioned below. Offset fault: Sensing circuits with sensors may have errors in them. It is found through the calibration process. This error is rectified by adding/subtracting with a displacement value in the real sensed data. Gain fault: The sensed data are processed by a circuit in the sensor node to change the sensed data to the required level. The processing circuit may deviate from the actual processing level. Stuck-at fault: In a digital circuit, the data are at a point to be changed based on input. However, the circuit is stuck with either zero or one permanently without changing.