# A 5G V2X Ecosystem Providing Internet of Vehicles +
## 2 Related Work  
IoV provides all Internet services to drivers, passengers and vehicles, and the SDIoV is nothing else than the integration of SDN with IoV. This brings the need for innovation to support IoV communications, services, and applications. In this proposal, challenges are pointed out, such as high efficiency in resources use, capacity increase, management, and control in a scalable and flexible way, as well the QoS (Quality of Service) in vehicular communication networks [4].  
When SDN is applied in IoV by disassociating the control and data planes, the controller simply manages the network and can shape the data traffic for the specific application. That is the reason why the SDIoV is expected to deal with the traditional vehicular networks shortcomings, offering efficient data transmission and traffic shaping in different vehicular scenarios, even with the routing protocols unaddressed in such environment limitations. In SDIoV, the packet routing can make IoV applications feasible while connected vehicles rely on the messages received from other vehicles and/or Road Side Unit (RSU) and, in such way, as the centralized controller has a global view of the whole network, an optimal route selection is easier [5].  
IoV needs non-stop technology evolution to answer all the new safety requirements and use cases that come with the Cellular Vehicle-to-Everything (C-V2X) development, in reason to provide a higher performance radio, while reusing upper layers defined by the automotive industry. The Third Generation Partnership Project (3 GPP) is used to define C-V2X and to specify service requirements for V2X systems, with an expectation to support several advanced scenarios [6; 7].  
In this direction, ITS and future vehicular networks require stringent requirements, and as already noted, these are hardly met through the IEEE 802.11p technology [8], that has 27 Mbps maximum throughput with V2X applications. As an alternative, the Long-Term Evolution (LTE) technology has been employed to support vehicle applications [9; 10], however the performance is affected by interference as shown by [11].  
The first V2X specifications involving cellular networks was provided in Release 14 of Long-Term Evolution-Advanced (LTE-A), focusing mainly on the aspects of vehicular safety applications, where was defined that vehicles should use a new PC5 interface for communication. It is because the LTE for vehicle standard supports side link or V2V communications using a direct interface on modes 3 and 4 which got physical layer changes introduced by Release 14, and its evolutions are being discussed on Release 15 to support 5G-V2X autonomous vehicles' applications [12].  
The 5G network integrated with SDN and Mobile Edge Computing (MEC) [13] appear as a good candidate technology for Vehicular Ad hoc Networks (VANETs) operational improvement, in terms of data rate, coverage, and QoS. There are other works that present interesting points to be considered for the 5G development common work, such as a four-tier architecture for urban traffic management [14]. Even SDN has already been used for vehicular networks, it has limitations in RSU when there is a high density of vehicles, by presents frequent handovers, what degrades its performance [15].  
In [1], the authors found that there is a minimum transmission delay, in accordance with different densities of vehicles. With the fog cell use, the authors were able to demonstrate an improvement on the transport management system performance. However, problems on the multi-hop routing retransmission and gateway vehicle selection on the proposed structure persist, which directly affects the system performance. Finally, a next generation 5G topology structure, using SDN controllers and a fog computing framework with zones and clusters to avoid frequent handovers between vehicles and RSUs is presented in [16].