## 1 Introduction  
Nowadays, mobile ad hoc networks (MANETs) are becoming a pivotal trend in modern life to keep pace with an accelerated world and rapid technological advances. In this context, the desire for low-cost installation and smarter and more connected devices is dramatically growing. MANETs foster a wide range of vital applications in industries, military operations, emergency situations, Intelligent Transport Systems (ITSs), intelligent health care systems, etc. [1, 2]. Accordingly, MANETs are classified into various categories, such as Vehicular Ad hoc Networks (VANETs) for smart cities, Internet of Vehicles (IoV) for smart automobiles, Flying Ad hoc Networks (FANETs) for the communication of Unmanned Aerial Vehicles (UAVs), and the Sea Ad hoc Network (SANET) to communicate with Autonomous Underwater Vehicles (AUVs), vessels and boats [3, 4, 5]. Some types of wireless ad hoc networks (WANETs) and their communication applications are shown in Figure 1. This classification can be a helpful guideline for designers and researchers to understand the specific requirements, challenges, and design considerations associated with each network, in addition to the specialized routing protocols, algorithms, and system architectures [6, 7]. Although MANET appears simple and versatile in various applications, the design of an efficient routing protocol for data communications in such networks is still a challenging task. Since the topology of the network changes rapidly and nodes can join or leave the network at any moment, this leads to a remarkable problem in choosing the relevant forwarding node and routing the packets. To this end, the vital issue is to design efficient routing protocols that are mobility-aware to find the optimal routes between communicating nodes and ensure better routing with less overhead and high network reliability [8; 9; 10]. Typically, the traditional topology-based routing protocols are mainly classified into three categories: reactive (on-demand), proactive (table-driven) and hybrid. These routing schemes are widely developed to cope with various challenges like high node mobility and dynamic network topology, transmission power or energy restrictions [11; 12]. Specifically, such schemes allow the nodes to set an entire route before forwarding data packets, causing high control overhead due to the dynamic topology of MANETs. For example, reactive routing protocols, such as AODV (on-demand routing), do not adapt well in high-mobility environments [13]. On the other hand, geographic routing protocols have been shown more interest due to their location awareness via using a Global Positioning System (GPS) device or running localization algorithms. In effect, these approaches employ non-flooding-based route discovery and offer high scalability for large-scale networks depending on the nodes' position information. This means that nodes must know their own positions before broadcasting their beacons' \"Hello\" messages. Also, such routing protocols do not necessitate the setup of a route management process or link maintenance [14; 15; 16]. Instead, the routing decision requires only the position information, i.e., the nodes need only maintain one-hop neighbor information for routing decision; this makes them more robust and efficient protocols for dynamic networks. However, such routing mechanisms have some drawbacks because the position information of each node may change due to network conditions such as GPS devices that may not work well in some locations like tunnels because of the absence of satellite signals. Besides that, a high mobility of nodes may change the network density from sparse to dense or vice versa. In consequence, this will increase the links' breakages of one-hop neighbor nodes and degrade the accuracy of neighbors' awareness [17; 18].