d services: A 5G satellite network can be used for content on-demand downloads in low-density areas. Imagine a government university providing online courses or degrees to students living in the desert or mountainous areas. They could download the content in regular intervals leveraging satellite multicasting. More information can be found at https://www.microwavejournal.com/articles/33942 the-role-of-satellites-in-5g-networks.l - Figure 16.10 shows how the 5G network integrates with the satellite network. Bent pipe Satellite Handheld or loT device (= RF repeater) 5G Core NR radio NR radio network NG (=N2/N3) network protocols protocols Regenerative Satellite Handheld or loT device (Including gNB/DU) gNB/CU 5G Core NR radio network Flinterface network NG (=N2/N3) protocols Figure 16.10 - Satellite integration with the 5G network 5G and Satellite Communications We looked at the need for SATCOM in the context of 5G in this section. Next, we will look at the architectural needs to support that. The architecture of 5G and satellite communications Let us look at the architecture of satellite communication in the context of 5G networks. We have already learned about three types of satellites: Geostationary Earth Orbit (GSO): Some examples include the PanAmSat, Intelsat, and Inmarsat satellite systems Medium Earth Orbit (MEO): The Galileo satellite and GPS are some examples. Low Earth Orbit (LEO): Starlink, Viasat, Iridium, and Globalsat are some examples. Figure 16.11 is a diagram of the different types of satellite orbits around the earth. Many of these satellites co-exist with the terrestrial networks to create a 5G satellite-based network. GEO: ~35K Km 600-800 ms MEO: ~8K Km 125-325 ms LEO ~1K Km 30-50 ms Figure 16.11 - Satellite orbits Figure 16.11 shows that GEO satellites cause a latency of 600-800 milliseconds (ms) for the roundtrip. This roundtrip latency drops down to 125-325 ms for MEO, and for LEO, to 30-50 ms. The power needed by end user devices is greater when using GEO or MEO. LEO allows direct connectiv