## 1 Introduction  
The Internet of Things (IoT) connects objects, people, various systems, and information resources to manage information from the real and virtual world and provide intelligent services. IoT features objects that recognize a situation, and many IoT systems are required to provide services related to objects that know their surroundings and are associated with them. With the development of wireless communication technology and micro-electronic mechanical systems (MEMS) technology, the IoT can be used in various applications that require wireless communication technologies, such as transportation devices, healthcare, military, and smart homes [1; 2; 3; 4]. Wireless sensor networks (WSNs) can be considered an Internet extension of the physical environment in IoT and are a component of the IoT system and IoT community [5]. WSNs consist of sensor nodes that have limitations regarding battery lifetime. Sensor nodes can detect the surrounding environment, configure the network, and transmit data, and data from sensor nodes can be sent to the user via the base station (BS) [6; 7; 8; 9]. The battery lifetime of the sensor node is the most important factor to consider when designing WSNs. Therefore, improving the network performance of IoT systems must be the focus, by designing energy-efficient WSN protocols. A sensor node is a hardware device that senses the environment, processes data, and transmits data. The sensor node consists of a sensing unit, processing unit, communication unit, and power unit, as shown in Figure 1. Depending on the application, it may also have a location finding system, mobilizer, and power generator. The sensor nodes collect the sensed data and transmit them to the BS located between the sensor nodes. Sensor nodes are small, are lightweight, and have low production costs, they also have many limitations such as energy, memory capacity, and processing speed [10; 11; 12]. These constraints affect the communication distance and data processing speed between sensor nodes. WSNs are used in various fields, such as terrain, climate, military, and ecological monitoring. The sensor node is randomly arranged according to the environment and purpose or is placed at a designated location. The deployed sensor node constructs the network and transmits the collected information to the BS. During this operation, data communication should be performed in an energy-efficient manner. The routing protocol of WSNs can extend the lifetime of WSNs by designing and implementing the efficient use of the energy of the sensor node [13]. The routing protocol of WSNs can be divided into flat network routing, hierarchical routing, and location-based routing depending on the network structure. The hierarchical routing protocol divides sensor nodes into clusters and has a hierarchy of cluster headers (CHs) and member nodes in the cluster. Clustering in WSNs is a protocol for reducing the energy usage of sensor nodes. Cluster-based routing increases energy efficiency, reduces transmission latency, and improves network scalability [14]. Clustering selects a representative node called a cluster header among the sensor nodes scattered in the field, and the CH collects data from peripheral nodes and transmits them to the BS. Sensor nodes can conserve energy by sending data to the BS via the CH [15]. Therefore, by selecting  
Figure 1: The components of a sensor node. the CH among the sensor nodes, energy usage can be reduced and the life of WSNs can be extended. The low-energy adaptive clustering hierarchy (LEACH) is a cluster-based hierarchical routing protocol for cluster configuration and data transmission. LEACH saves the transmission energy of the sensor node by transmitting data after configuring the cluster [16; 17; 18; 19; 20]. Many studies have been conducted to improve CH elective and data transmission methods in LEACH. Meanwhile, in this study, we focused on reducing energy loss caused by reverse transmission in LEACH.