The unmanned aerial vehicles (UAVs) are new types of user equipment connected to cellular networks with promising revenue through additional new subscribers and use cases, especially for aviation sector. In addition, UAVs are accepted as an extension to base stations by boosting coverage, spectral efficiency and user quality of experience. In this context, the main aim of this project is to provide high quality of data link and smooth UAVs connectivity into cellular network infrastructure. The UAVs allow rapid deployment of a multi-hop communication backbone in challenging environments with applications for public safety, delivery and monitoring. Therefore, Unmanned aerial vehicles (UAVs) can be used as complementary infrastructure to provide wireless services for the ground users or they may require wireless connectivity from the ground for a safe and reliable operation. This PhD project aims to study several UAV use-cases covering 5G core networks and to validate UAV/UTM connectivity KPIs for supporting such challenging. The project will drive UAV and 5G networks to a win-win position, on one hand by showing that 5G is able to guarantee UAV vertical KPIs, and on the other hand by demonstrating that 5G can support challenging use-cases that put pressure on network resources. To achieve that we will look to study of where 5G can add value to improve the existing UAV connectivity.