# REERP: A Region-Based Energy-Efficient Routing Protocol for IoT Wireless Sensor Networks
## 1 Overview of Wireless Sensor Networks  
Wireless Sensor Networks (WSNs) typically consist of large quantities of tiny sensors, their basic component. These sensors enable measurements that are made up of a physical system, such as heat, humidity, vibrations, noise, object presence, etc. [1]. The sensing unit, processing unit, transmission unit, and power supply unit are the four essential parts of a wireless sensor. Data gathering, data processing, and two-way interaction with fewer sensor nodes are its three main functions [2]. A base station (BS) receives from the nodes the data sensed from the environment. The nodes have relatively restricted capabilities, particularly in terms of power supply; to power their numerous operations, they often rely on small batteries. To be able to identify the node's location, a wireless sensor can be fitted with a location system. Some applications that rely on sensors to roam around and complete tasks may sometimes require a mobility system. Most of the time, the energy source is severely restricted and rarely renewable due to the intensive deployment of WSNs [3]. This results in a reduction in energy use and extended network longevity. To ensure that sensor networks last as long as possible, optimal energy utilization must be handled. Several network levels, from the physical layer to the application layer, must take into account energy efficiency. Many definitions and concepts used in previous systems areinsufficient for this generation of networks due to the unique properties of WSN, which must use energy efficiently to ensure the delivery of data to the user as long as needed. Energy is a major constraint. From its very beginnings, the IoT has helped humanity significantly as a WSN, notably in obtaining data from censorious settings. Networks can collect, process, and transfer data from disastrous environmental situations to secure locations. In these networks, when data are collected, the data are often transmitted to the BS, a received node, for additional processing [4]. Small sensor nodes often make up these networks. Sensor nodes use rechargeable and interchangeable batteries as their energy source. Whenever these batteries are used in a hazardous environment, it is difficult to recharge and replace them. As a result, the network's efficiency is always enhanced by the effective utilization of the sensor nodes' scarce resources. The development of techniques (see [4], for example) that can reduce node energy degradation and increase network longevity can boost a WSN's efficiency. After being deployed, sensor nodes are regarded as independent; however, how well they manage their energy utilization will determine how long they last. The secret to reducing node energy utilization and extending network longevity is to develop energy-efficient data-gathering methods. WSNs frequently use clustering with multilevel topologies to reduce energy utilization and ensure a longer-lasting network than those relying solely on direct connection [5]. In this paper, minimized energy utilization for data to be transmitted from the sender to the base station is the major goal. From the sender to the receiver via one or more intermediate nodes; to accomplish the transmission of data, the data are forwarded. In clustering hierarchical structure techniques, the network nodes are organized into multiple regions, which are each headed by a master node called the cluster head (CH), with the remaining nodes being referred to as cluster members. Although each cluster head has a unique set of responsibilities, their primary duty is to acquire the data from the cluster members, which they later transmit to the base station. Providing sensor data in packets rather than each node transmitting direct data to the base station usually requires more energy and causes the node to rapidly lose energy, and this design lowers the energy used for transmitting data. Data processing and consolidation using clustering techniques are quite effective.