## 9 Challenges
### Integration  
The integration of the Internet of Vehicles (IoV) and the Internet of Flying Vehicles (IoFV) into a network is an undertaking that involves various considerations such as security, infrastructure, existing technologies, and frameworks. Ensuring security measures is crucial. Achieving successful integration also requires leveraging current infrastructure and technologies while accommodating the unique characteristics of both ground and aerial transportation systems. When it comes to security, a comprehensive approach is needed. This includes implementing encryption techniques, secure communication protocols, robust authentication mechanisms, and measures to protect the infrastructure. These security measures should align with existing frameworks while addressing the challenges posed by merging the IoV and IoFV. Infrastructure readiness plays a role in this integration [194]. The physical and communication infrastructure must be designed to cater to the needs of ground and flying vehicles. This involves deploying traffic management systems for ground vehicles, as well as establishing air traffic control mechanisms for flying vehicles [195]. Existing technologies and frameworks significantly influence how this integration takes shape. Utilizing communication protocols, such as V2X communication for ground vehicles and UTM for flying vehicles improves the efficiency and compatibility of communication [196]. By integrating with established intelligent transportation systems (ITS) frameworks, we can facilitate data exchange and contribute to a more cohesive and effective transportation ecosystem [197]. To ensure an integration process, it is important to examine existing models of the IoV (Internet of Vehicles) and IoFV (Internet of Flying Vehicles). Noteworthy examples in the IoV domain include the C-V2X (cellular vehicle to everything) platform, which employs networks for vehicle communication [198], as well as DSRC (dedicated short-range communication), which is a wireless technology designed specifically for vehicular communication [199]. On the IoFV front, UTM (unmanned traffic management) models offer a framework for managing and monitoring low-altitude airspace to enable efficient drone operations [200]. In order to meet the communication needs of ground and flying vehicles, it may be beneficial to consider a communication infrastructure. This approach involves combining DSRC for ground vehicles with satellite-based communication for flying vehicles to optimize coverage and reliability [154]. Additionally incorporating edge computing capabilities allows for critical data to be processed closer to their source, thereby reducing latency and improving real-time decision making in areas like collision avoidance and route optimization [201]. Furthermore, integration extends beyond software systems; retrofitting existing infrastructure with sensors and communication devices can enhance the responsiveness of our transportation network [202]. This involves implementing traffic lights with embedding sensors [203] in roadways and establishing communication infrastructure at landing pads and airports to enable operations within the Internet of Vehicles (IoV) and the Internet of Flying Vehicles (IoFV) [204]. Collaboration is crucial to tackle the challenges associated with integrating infrastructure and technology. Collaborations between government entities, technology providers, vehicle manufacturers, and urban planners through partnerships encourage a cooperative approach toward standardization, policy development, and the creation of interoperable frameworks [205]. To summarize, successfully combining the IoV and IoFV into a network requires the consideration of security measures, existing technologies, infrastructure requirements, and frameworks. By aligning these elements with the needs of ground and flying transportation systems, we can establish an integrated network that operates efficiently.