## 1 Introduction  
Nowadays, WSN plays a vital role in the modernization of daily life. The interconnection of smart wireless devices offers many easy services in various industrial, military, and civilian fields [1]. A sensor node can process the data collected from the physical environment, analyze them, and communicate them in transmitting or receiving mode. As a new data-collection technique, these networks have replaced wired sensor networks due to their advantages such as low cost and easy deployment. When the whole wireless network is based on a big number of distributed sensor nodes, it mainly deals with keeping the quality of the node's communication as high as possible. In line-of-sight or urban environments, WSN faces a lot of physical or environmental conditions, such as humidity, temperature, and vibration [2]. Among the important challenges facing WSN is the reliability and robustness to enable better wireless communication. Additionally, the network energy efficiency poses a challenge, as the sensor nodes are generally battery-powered and require autonomous operating for a long time. In recent research,the focus was on enhancing the capabilities of the hardware node for the optimization of WSN challenges [3]. Modern research has tended to improve wireless sensor networks (WSNs) in terms of latency, sensitivity, and energy efficiency. Radio frequency (RF) communication started with receiver-initiated media access (MAC) protocols, where the node has to listen to the channel; as a result, the RF chip is powered to detect a potential beacon frame. This type of communication is not energy-efficient because idle listening is typically the primary source of energy consumption in receiver-initiated protocols [4]. Therefore, they switched to duty-cycled protocols where the receiver switches on for a period to listen for potential beacons. However, these protocols are limited in terms of latency. The revolutionary invention in the world of sensor nodes is WuRx, which is an ultra-low-power receiver included in addition to the main transceiver as a solution for the idle listening issue. The WuRx ship is always in receiving mode, plays the role of detecting the wake-up call (WUC), identifying it, and then sending an interrupt to the main transceiver through the microcontroller unit (MCU), which remains in sleep mode until receiving the interrupt from the MCU. Figure 1 presents a block diagram of a WuRx, showing the interconnection between the WuRx, the main transceiver, and the MCU, with an RF switch in between to route RF signals through the transmission path. The protocol scheme of the WuRx is simplified in Figure 2, indicating the transmission of the WUC when the receiver is in sleep mode. The data start transmission after identification of the WUC and activation of the main wireless chip. Currently, two WuRx approaches are being pursued. The first one is classified in the application-specific integrated circuit (ASIC) WuRx [6], and the second one is based on commercialized off-the-shelf (COTS) WuRx [7; 8]. The WuRx energy efficiency has switched investigations to the reliability of those receivers, because data-transferring performance relies on communication accuracy, which could be affected by external factors such as noise, interference, etc. One of the accurate methods used to determine the reliability of WuRx communication is to measure the PER according to the transmission power or the attenuation level, because this metric gives an overall idea about the sensitivity level of the sensor node [9]. Additionally, an RSSI that measures an approximate level of attenuation during the transmission [10] is used in some localization application techniques [11]. Figure 1: Wake-up receiver node block diagram according to [5]. The use of a simulator is a key for the investigation of wide networks before implementing them in real situations. The simulation reduces the cost and time of implementation. Additionally, the simulators give researchers a general idea of WSN behavior that can be deployed in the future.