5G-NTN GEO-based Over-The-Air Demonstrator using OpenAirInterface

5G services combined with the satellites, also termed 5G NonTerrestrial Networks (5G-NTN), have the capability of
providing connectivity to the areas which were previously
either unreachable or too costly to be reached by terrestrial
communication networks. Proof-of-Concept (POC)
demonstrators, preferably based on open-source
implementation are desirable to expedite the ongoing research
on 5G-NTN. In this work, we discuss the contributions made
during the project 5G-GOA: 5G-Enabled Ground Segment
Technologies Over-The-Air Demonstrator which aims to
provide direct access to 5G services to a UE through a
transparent payload Geostationary (GEO) satellite. 5G-GOA
uses the open-source Software-Defined-Radio (SDR) platform
OpenAirInterface (OAI) and does the necessary adaptations to
achieve its objectives. Adaptations span physical layer
techniques (e.g. synchronization) up to upper layer
implementations (e.g., timers and random-access procedures)
of the Radio Access Network (RAN). The adaptations are
based on 3GPP 5G-NTN discussions and the solutions are
compliant with the recently frozen 3GPP Release-17. An endto-end SDR-based 5G-NTN demonstrator has been developed
for Over-The-Satellite (OTS) testing. We present results from
several experiments that were conducted for in-lab validation
of the demonstrator using a satellite channel emulator before
going live with OTS tests. Experimental results indicate the
readiness of the demonstrator for OTS testing which is
scheduled during ICSSC 2022. The source code has been
submitted to OAI public repository and is available for testing.