## 2 Internet of Vehicles and Smart Cities
### The UAV and the Smart City Paradigm
#### 2.5.2 Smart Cities  
As stated before, the smart city is an extensive concept. It is a combination of perspectives with the purpose to optimize resources and their management sustainably and efficiently, as to improve the life of the citizens. [PERSON] et al. [41] list some _smart_ characteristics common to the smart cities' concepts:  
* _Smart Living_--any individual should be able to have quality health conditions, safety, and cultural and educational access, also good accessibility in its housings. \begin{table}
\begin{tabular}{c c} \hline
**Security Requirement** & **Description** \\ \hline _Data authentication_ & Vehicles identities should be verified when transferring data \\ _Data integrity_ & Sent and received data should be verified to ensure correct data transferal \\ _Data confidentiality_ & Data transmission between vehicles should be secret \\ _Access control_ & Vehicles should be allowed to access services they are entitled to \\ _Data non-repaliation_ & Vehicles should not be able to deny the authenticity of another vehicle \\ _Availability_ & Communication between vehicles should be ensured even under bad conditions in the event of an attack \\ _Anti-jamming_ & Malicious vehicles cannot interrupt communications between other vehicles \\ _Impersonation_ & A vehicle cannot impersonate another entity in the network \\ _ID traceability_ & A vehicle’s identity can be retrieved from sent messages \\ _Vehicle_ & Sent messages can only be accessed by authorized vehicles and remote nodes. The vehicle’s identity \\ _privacy/inonymity_ & should be hidden. \\ \hline \end{tabular}
\end{table} 
Table 1: Security requirements for IoV [34]. * _Smart Mobility_--any individual should be able to access its territory from local to a national scope. Intelligent Transportation Systems intermediate these accesses so that they can be made safely and sustainably. * _Smart Environment_--any smart city should deliver good land use planning, reasonable pollution control, proper natural resource usage. * _Smart Economy_--any smart city should promote local product use (local economy), incentivize entrepreneur, and innovation culture based on e-services. * _Smart People_--any individual should be invited to incorporate life-long learning precepts, social and ethnic diversity precepts, community and creativity sense, and a citizen-level awareness. * _Smart Governance_--any smart city should be governed with transparent, public decisions and have public and social services. To achieve these, various technologies have to interoperate simultaneously and share information to process the state of the various environments and, finally, make decisions. However, this interoperability can be a difficult challenge to overcome and that is where IoT and IoV come into place. They guarantee interoperability in their networks, as well as offer properties such as security, scalability, and big data management, that are essential for a safe and reliable smart city. Given the expected increase in connected devices in the near future, be it vehicles or non-mobile sensors and base stations, maintaining these wireless connections with low latencies and quality of service requirements is one of the major challenges for smart cities. The emerging 5G technologies and new computing paradigms (fog, edge, and cloud computing), as mentioned above, can prove to be a viable solution to these problems, but a change in the way we perceive the network topologies can also improve the outcome of these implementations for the better. Through the usage of UAVs as DBS, which can communicate with ground base stations (GBS), the coverage of networks substantially increased, allowing for more devices to be connected in a bigger area, enabling the communication between devices in different locations in the same city that otherwise wouldn't be able to and expanding the coverage of administrative services to the whole city. This is showcased in Figure 7, where DBS's are used with 5G technology to extend the coverage area of services for other vehicles and users.