lites involved for the ISL part. According to 3GPP TR 38.82117, the two typical scenarios of a satellite-based NTNs providing access to UE are depicted as follows: Satellite Satellite (or UAS platform) (or UAS platform) Feeder link Feeder link (mandatory if no ISL) network Service Gateway equipments Beam foot print Field of view of the satellite (or UAS platform) Figure 16.19 - Scenario 2 of NTN architecture 5G and Satellite Communications Finally, in Figure 16.20, we look at the TN and NTN communication scenario based on the interoperability of GEO and LEO satellites, to provide global coverage. Mobility between TN and NTN GEO Satellite Non-GEO Satellite Terrestrial gNB Very high-speed/aerial vehicle Limited/primary TN conn. Wide/secondary NTN LEO/GEO conn. Low-speed ship Remote Outdoor Medium/high-speed vehicle/ A2G systems Indoor/outdoor Low-speed, pedestrian Rural/ area/sea Limited/secondary train Rural/suburban area remote area Good/primary TN conn. TN conn. Good/primary NTN Good/primary TN conn. Wide/ Wide/secondary NTN LEO conn. LEO/GEO conn. secondary NTN LEO conn. Figure 16.20 - NTN network architecture between different types of satellites With support for the three different scenarios of NTN-based communication, 5G can truly provide a global reach and overcome the lack of terrestrial cell towers in every part of the earth - the land and the oceans (https://www.5gamericas.org/wp-content/uploads/2022/01/5G- on-Terrestrial-Networks-2022-WP-Id.pdf) - Let us evaluate security implications next. Under the NTN architecture, the current 5G security considerations will apply to NTN and 5G communication. The key considerations will remain as follows: Authentication and authorization Integrity and replay protection Confidentiality protection Privacy may emerge as the next consideration for this area. With mobile UE, the location and movement of people or assets can be subject to privacy requirements. We may see future evolutions of security implementations at the interface of the satellite GW and current 5G syste