# Seamless Handover Scheme for MEC/SDN-Based Vehicular Networks
###### Abstract  
With the recent advances in the fifth-generation cellular system (5G), enabling vehicular communications has become a demand. The vehicular ad hoc network (VANET) is a promising paradigm that enables the communication and interaction between vehicles and other surrounding devices, e.g., vehicle-to-vehicle (V2V) and vehicle-to-everything (V2X) communications. However, enabling such networks faces many challenges due to the mobility of vehicles. One of these challenges is the design of handover schemes that manage the communications at the intersection of coverage regions. To this end, this work considers developing a novel seamless and efficient handover scheme for V2X-based networks. The developed scheme manages the handover process while vehicles move between two neighboring roadside units (RSU). The developed mechanism is introduced for multilane bidirectional roads. The developed scheme is implemented by multiple-access edge computing (MEC) units connected to the RSUs to improve the implementation time and make the handover process faster. The considered MEC platform deploys an MEC controller that implements a control scheme of the software-defined networking (SDN) controller that manages the network. The SDN paradigm is introduced to make the handover process seamless; however, implementing such a controlling scheme by the introduction of an MEC controller achieves the process faster than going through the core network. The developed handover scheme was evaluated over the reliable platform of NS-3, and the results validated the developed scheme. The results obtained are presented and discussed. v 1 2022 20  
low-latency use cases such as vehicular communications, augmented and virtual reality (AR, VR), and the Tactile Internet [4, 5]. Furthermore, 5G is expected to achieve a spectrum efficiency improvement of 5 to 10 times, and the user experience can be guaranteed at a speed of 500 km/h. Fifth-generation cellular systems face many challenges, including the massive traffic that is expected to be 1000 times that of the existing systems [6, 7]. One of the main objectives of 5G systems is to improve the end-user experience by providing current services and introducing new services and applications with low/ultralow latency, a high data rate, ultrahigh reliability, and ultrahigh availability [8]. Vehicular communication is one of these 5G use cases, which is intended to provide the infrastructure and coverage for vehicles with heterogenous mobility [9]. Vehicular systems are inseparable components of a smart city environment due to several applications that improve the quality of life, safety, and security of the city [10]. Vehicular networks provide the infrastructure and communication coverage to vehicular devices with heterogenous mobilities, including high mobility. The applications of vehicular networks vary from safety applications such as blind-spot warning and traffic light violations to entertainment such as streaming media and convenience such as parking space identification [11, 12]. Recently, many standards have been established for vehicular communications, such as the IEEE 802.11p and IEEE 1609 family group [13, 14]. These standards achieve effective communication between vehicles and infrastructure. However, vehicular ad hoc networks (VANETs) are still considered a challenging form of the wireless communication technology that complements intelligent transportation systems (ITS) aiming to improve transportation in cooperation with information and communication technologies (ICTs) [15]. VANETs are mobile ad hoc networks (MANETs); however, protocols that perform well in MANETs may not be a great fit for VANETs, due to the usage conditions of high mobility, intermittent connectivity, and heterogeneity. The dramatic increase in the number of vehicles, especially in crowded cities, adds more constraints to the network design.