5G NR and DVB Simulations for Future-Proof NGSO Systems: DVB Project

September 2, 2025

Two satellites orbiting the Earth with the sun reflected in the background

As NGSO satellite constellations grow larger and more complex, it’s important to ensure that these systems are built on reliable, future-proof technologies.

Commissioned by the DVB Project, Magister simulated the performance of alternative technologies for current and future NGSO systems: 3GPP 5G NR NTN, DVB-S2X, and DVB-RCS2.

These evaluations are crucial information for operators planning to deploy future NGSO (Non-Geosynchronous satellite Orbit) based services.

Evaluating 5G NR and DVB performance for future NGSO systems

During the spring of 2025, Magister conducted system simulations for the DVB (Digital Video Broadcasting) Project. In Low Earth Orbit (LEO) satellite scenarios, we compared the 5G NR NTN (5th Generation New Radio Non-Terrestrial Network) technology to DVB-S2X (2nd Generation Satellite Extensions) and DVB-RCS2 (Return Channel Satellite 2nd Generation).

We performed return link simulations in which we compared NR NTN and DVB-RCS2/DVB-S2X waveforms. DVB-S2X waveforms in the return link are a new addition to the DVB standard, whereas previously only DVB-RCS2 was specified. Through these simulations we wanted to examine the performance of the old and updated standard in comparison to NR NTN in NGSO environments.

This was a continuation of our previous simulation work, such as the research executed for the paper “Simulative Comparison of DVB-S2X/RCS2 and 3GPP 5G NR NTN Technologies in a Geostationary Satellite Scenario”, which won the Best Paper Award for Industrial Relevance at the ASMS/SPSC 2025.

These recent evaluations completed for DVB introduced new effects such as signal degradation from the Doppler shift and losses in gain when using Electronically Steered Antennas. The main goal was to compare the performance of DVB-S2X and DVB-RCS2 against another candidate for current and future satellite systems – 3GPP (3rd Generation Partnership Project) 5G NR NTN.

Our simulative evaluations provide crucial information for operators that are looking to deploy NGSO-based services. In-depth system-level simulations help support decisions about e.g. which technologies to invest in to maximize system reliability and readiness for future use cases.

Developing specifications for digital media delivery at the DVB

In the DVB (Digital Video Broadcasting) Project, the world’s leading media and technology companies work together to create open technical specifications for digital media delivery.

Through working groups, DVB members develop specifications for digital television systems, which are turned into standards by international standardization bodies such as ETSI (European Telecommunications Standards Institute).

DVB has developed standards for satellite communications, the most prominent of which are DVB-S2X for the forward (download) link and DVB-RCS2 for the return (upload) link.

NGSO constellations provide high-speed internet connectivity around the world

Momentum has been building around NGSO constellations in recent years, including well-known examples such as SpaceX’s Starlink, Amazon’s Kuiper, and Eutelsat OneWeb.

While these abovementioned constellations focus on delivering global high-speed internet connectivity, NGSO constellations also have other applications, such as Earth observation. NGSO constellations encompass satellites in Low Earth Orbit (LEO) and Medium Earth Orbit (MEO).

NGSO satellites orbit the Earth at lower altitudes, whereas the altitude of traditional Geosynchronous Orbit (GSO) satellites is approximately 36,000 km around the equator. GSO satellites appear stationary since they move in sync with the Earth’s rotation, but NGSO satellites are visibly moving at a faster speed. This means that a constellation of NGSO satellites is needed to constantly cover a given point on Earth.

One of the most challenging aspects of NGSO operation is the frequently changing, potentially very high Doppler shift. It’s a frequency change caused by the high-speed movement of satellites relative to the user. This phenomenon is a lot more pronounced in NGSO systems compared to GSO or ground-based networks.

However, since satellite trajectories are predictable, most of the Doppler shift can be compensated. In this case, tests were performed for varying levels of compensation, simulating real-life conditions such as antenna tracking and satellite movement.

Analyzing Doppler resilience in a LEO-600 satellite environment

We utilized two of our own simulators for conducting the evaluations: SNS3 and ALIX. They’re both extensions of the ns-3 simulator (Network Simulator 3), and both have been developed in European Space Agency projects.

SNS3 models a fully interactive multi-spot beam satellite network with a single satellite. ALIX is a 5G TN-NTN (Terrestrial / Non-Terrestrial Network) System Level Simulator that has been developed for the purpose of successful standardization of NTN in the 3GPP.

The performance of the NR NTN and DVB return links were evaluated at system level in a LEO regenerative satellite payload scenario, using Ka-band frequencies (30 GHz in the return link). We utilized 3GPP LEO-600 satellite calibration scenarios and 3GPP VSAT (Very Small Aperture Terminal) characteristics.

The Doppler effect is a critical phenomenon in LEO systems due to the high relative speed of the satellites compared to ground users. In system-level evaluations, we compared DVB with NR NTN under three different Doppler compensation values: full, 99.3%, and 97.5% compensation for the Doppler shift.

The uncompensated Doppler in the simulated scenario was around 270-380 kHz, which was reduced to around 2-3 kHz (99.3%) or 7-10 kHz (97.5%) when compensation was applied.

DVB demonstrated more reliable performance in real-world conditions

Through our simulations, we observed NR PUSCH (Physical Uplink Shared Channel) to be more susceptible to Doppler degradation compared to DVB. All DVB return link variations demonstrated an increase in performance gain over NR PUSCH as the residual Doppler shift increased.

DVB waveforms showed greater resilience to Doppler effects, especially at moderate compensation levels. They enjoyed an average of 2-3 dB better signal-to-interference-plus-noise ratio (SINR).

With ideal compensation, NR PUSCH was seen to perform better overall than the DVB waveforms. Nevertheless, under less than ideal conditions, DVB waveforms showed stronger, more reliable performance. Given that real-world environments are often far from ideal and terminals vary in capability, robust and consistent performance in challenging environments is a key advantage.

It is important to note that these results are highly sensitive to changes in the simulated configuration, e.g. adaptive coding and modulation (ACM) and channel estimation parameters. However, the findings provide a clear picture of the general trend and magnitude of technology performances, when Doppler effects are applied.

> Magister Solutions: Simulation Report on the Comparison of DVB RCS2 and 3GPP NR NTN Technologies in LEO Systems

> DVB White Paper: System-level Simulations for Non Geosynchronous Satellite Orbit (NGSO) Constellations

Magister Solutions is a Finnish company that specializes in communication network simulation tools and services for modelling real-world communication systems (satellite and terrestrial) in detail.

As an independent company, we provide the industry with unbiased simulation-based evaluations of network and communication technology performance. This supports standardization and helps organizations make informed decisions about technology investments.