Non-terrestrial networks (NTNs) are becoming increasingly more critical in providing wireless connectivity to areas where terrestrial networks cannot ensure coverage. Because NTNs operate above the earth’s surface, they can deliver seamless coverage to remote areas that lack traditional wireless access and increase overall resilience.
One use case in which NTNs are essential is public safety. Natural disasters or other acts can often make terrestrial networks inoperable. NTNs can help ensure first responder communications in those instances, aiding in protecting police, fire, EMS, and the general public.
NTNs have many technical challenges that must be overcome to fill those coverage gaps successfully. Examples include round-trip delays and cell mobility, which were addressed in 3GPP Release 17.Recognizing the obstacles associated with NTNs and implementing proper testing procedures will help ensure operation and improve wireless connectivity in critical areas and situations.
NTN Satellite Types
Typically, NTNs utilize satellites in low earth orbit (LEO), medium earth orbit (MEO), and geostationary orbit (GEO). High-altitude platform systems (HAPS) – balloons, airships, or powered fixed-wing aircraft that fly or float at altitudes of approximately 20 km – and drones are also used in specific networks.
Three satellite types (figure 1) are used in an NTN. As noted in the chart, latency is related to altitude. The higher the altitude, the longer the coverage. The more comprehensive the coverage, the slower the latency.
Satellite-based NTNs consist of several elements. Gateways connect the NTN to a public data network. There are also feeder or radio links between a satellite gateway and the satellite itself. Finally, a service or radio link exists between the UE and the satellite.
This article is posted at anritsu.com
Please fill out the form to access the content
