Shared Access Satellite-Terrestrial Reconfigurable Backhaul Network Enabled by Smart Antennas at MmWave Band

5G traffic expectations require not only the appropriate access infrastructure, but also the corresponding backhaul infrastructure to ensure well-balanced network scaling. Optical fiber and terrestrial wireless backhaul will hardly meet 100 percent coverage, and satellite must be considered within the 5G infrastructure to boost ubiquitous and reliable network utilization. This work presents the main outcomes of the SANSA project, which proposes a novel solution that overcomes the limitations of the traditional fixed backhaul. It is based on a dynamic integrated satellite- terrestrial backhaul network operating on the mmWave band. Its key principles are seamless integration of the satellite segment into terrestrial backhaul networks, a terrestrial wireless network capable of reconfiguring its topology according to traffic demands, and aggressive frequency reuse within the terrestrial segment and between terrestrial and satellite segments. The two technological enablers of SANSA are smart antenna techniques at mmWave and software defined intelligent hybrid network management. This article introduces these 5G enablers, which permit satellite communications to play a key role in different 5G use cases, from the early deployment of 5G services in sparse scenarios to enhanced mobile broadband in denser scenarios.