Networking challenges for non-terrestrial networks exploitation in 5G

The standardization process of the fifth generation of mobile communications (5G) is still ongoing, with planned end in 2020. A lot of changes have been made from the previous generations involving different technologies, concepts, and paradigms, which will deeply affect the telecommunication infrastructure and its management. Besides, a higher number of use cases and application scenarios are envisioned in the near future. This will contribute in generating higher and higher traffic volumes from a higher number of connected devices/users with different performance requirements. Additional network resources are required to fulfill users' requirements in order to guarantee the expected Quality of Experience (QoE). The integration of Non-Terrestrial Networks (NTNs) within the 5G framework is under standardization and can lead to manifold advantages, such as coverage extension and additional communication link, among many others. However, NTN integration is also leading to challenges related to the employment and adaptation to aerospace networks of technologies originally designed for terrestrial networks. This paper provides an overview of the role of NTNs in the 5G ecosystem, of the application scenarios that can benefit from the integration among terrestrial and non-terrestrial networks, and of some identified challenges from the networking viewpoint, which still require further analysis towards possible solutions.