The comparison of DVB-S2X/RCS2 and 5G-NR (Non-Terrestrial Networks) technologies has become a highly relevant and debated topic in broadband satellite communication. Many stakeholders are currently contemplating which solution to invest in, given the technologies’ performance, advantages, and limitations.
MARINA project (Multi Access Relative Performance Comparison for GSO Broadband Satellite Networks) is addressing this subject. The project started in June 2023, and is targeting completion in spring 2024. In this project, Magister and Thales Alenia Space France (TASF) join forces, with Magister as the prime contractor and TASF as a subcontractor. The project provides an excellent opportunity for Magister to showcase its world-class simulation expertise but most importantly, promote worldwide standards for satellite networks.
MARINA is an ESA-funded project. It will monitor and contribute to the European Telecommunications Standards Institute (ETSI) SES-SCN work item “Comparison of DVB-S2x/RCS2 and 3GPP 5G-NR NTN-based systems for broadband satellite communication systems” led by the TC-SES/SCN working group.
DVB-S2X/RCS2 and 5G-NR NTN: Origins and applications
ETSI published the satellite broadcast technology referenced DVB-S2 in 2005, followed by the optional extension DVB-S2X in 2014. DVB-S2 is widely used for broadcast services, interactive broadband applications, and Digital Satellite News Gathering (DSNG). ETSI also published the technical specifications of an interactive satellite Return (RTN) channel under “DVB-RCS2” in 2014. The combination of DVB-S2X and DVB-RCS2 represents the state-of-the-art access technology for geostationary High Throughput Satellite (HTS) networks operating in Ku or Ka-Band. Both technologies have been developed by the DVB forum (www.dvb.org).
The 3rd Generation Partnership Project (3GPP) has been working on the support of non-terrestrial networks with 3GPP defined radio interfaces since 2017 as part of the Release 15, i.e. adding the capability to support NTN in existing 3GPP technical specifications. For example, Release 17 has defined features enabling to mitigate specific technical characteristics of non-terrestrial networks including extended/variable propagation delays and Doppler shifts, possible large and earth moving radio cells. The NTN standard defined during the Release 17, has been designed to support a wide range of deployment scenarios including GSO & NGSO based networks for broadband and/or IoT services and operating in any frequency bands.
In this comparison activity, we shall consider GSO based network operating in Ka-Band and addressing VSAT type user equipment. DVB-S2X/RCS2 access technology has been used in such SatCom networks for almost two decades. 5G NR radio interface with NTN enablers is a candidate alternative access technology considered for future satellite networks.
Comparing DVB-S2X/RCS2 and 5G-NR NTN
DVB-S2X/RCS2 and 5G-NR NTN protocols have distinct origins, and they were developed to meet different market needs and user requirements. DVB-S2X/RCS2 was optimized for broadband satellite transmissions, considering typical satcom transponder characteristics such as S/N ratio, propagation delay, gain flatness, phase noise, and amplitude linearity.
On the other hand, 5G-NR NTN is strongly influenced by the performance of handheld user devices operating at lower frequency bands in terrestrial cellular network topology, with its associated performance characteristics.
In ETSI SES-SCN work item “Comparison of DVB-S2X/RCS2 and 3GPP 5G-NR NTN-based systems for broadband satellite communication systems” the objective is to perform a qualitative and quantitative comparison of both access technologies, involving simulative studies at the link and system levels. The project also aims to identify potential enhancements for 5G-NR and contribute potential findings to the 3GPP standardization process.
In the MARINA project, Magister will focus on system-level simulations, while TASF will concentrate on the link level simulations.
The goals of the MARINA project
The MARINA project has identified several technical objectives:
- Compare the performance of DVB-S2x/RCS2 and 5G-NR NTN protocols in higher frequency bands typically used in satcom applications for broadband satellite services.
- Monitor and contribute to the ETSI SES-SCN working group’s ongoing work on comparing DVB-S2x/RCS2 and 5G-NR NTN systems.
- Identify potential improvements for 5G-NR NTN in GEO HTS scenarios, generating inputs for consideration under 3GPP Release 18 and beyond.
- Investigate techniques to reduce the Peak-to-Average Power Ratio (PAPR) when operating on multiple 5G-NR or DVB-S2x carriers.
- Propose a list of recommended follow-up activities to overcome the identified performance issues, especially those related to 5G NR/NTN.
The projects’ results will be available to anyone participating in ETSI standardization. It will be very useful to understand the characteristics and operational constraints of 5G-NR NTN access technology wrt DVB ones for future broadband satellite networks.