Introduction and Problem Statement

After a number of years of research and technical development, the initial 5G New Radio technology according to Release 15 is currently deployed by Mobile Network Operators as mainstream technology serving the public and industry. As in LTE, there will be several evolutions of New Radio as well within the upcoming 3GPP releases. Many extensions are currently under investigation in 3GPP to enable further markets to be addressed by cellular based communication systems, like automotive, positioning and industrial production/automation.

There is a unique opportunity in 3GPP to standardize satellite as an integral part in 5G as part of the Release 17 together with the cellular stakeholders given their increasing interest in the topic. This opportunity has to be seized immediately to prevent the risk of a postponement of the standard development to future Releases beyond 17 while SatCom users and service providers are calling for standardized solutions.

Since June 2018, the study item report for Non-Terrestrial-Networks (NTN) TR 38.811 ([1]) is available, including the referenced documents in this activity definition. TR 38.811 summarizes the identification of New Radio impacts for satellite operation and gives recommendations for the actual running second study item on NTN in Rel-16 ([2], [3]), which will be finalized by March 2020. The study item report [3] is updated continuously.

The 5G METEORS vision is to implement and operate a framework supporting dynamic prototyping in the 5G satellite convergence domain, responding in an agile manner to technology developments driven by the market and the standardization work in 3GPP to support satellites in 5G. More specifically, 5G METEORS plans to draw on the expertise, knowledge and know-how developed and accumulated in Germany in the 5G and satellite communication domains by experts at academia, in small and large enterprises, as well as by entrepreneurs, and offer an opportunity to further expand through a series of prototyping and concept validation activities.

5G METEORS activities will be tightly associated with the 3GPP standardization organization process and shall foster the standardization of 5G satellite integration in Releases 16 and 17. For all 5G METEORS activities, their topic match and their timeliness will be evaluated in regard of the overall 3GPP schedule for the upcoming releases and especially for the work to support satellite in 5G.

Objective and work to be performed

This activity shall implement in real-time on a SDR platform relevant parts of the lower layers (PHY, MAC) of the 5G NR waveform (accompanied e.g. by a simplified control plane) with the necessary adaptations according to 3GPP NTN studies, to enable detailed performance analysis of NR over satellite. The SDR implementation should at least support a RF carrier bandwidth of 40 MHz to enable broadband applications.

Operating New Radio over satellite requires essential adaptations according to 3GPP work (TR 38.811, TR 38.821) and ITU work (ITU-R M.2047 for LTE adaptations, [4]). Using a closed source platform in this case is not possible for specific demonstrations of satellite capabilities. A number of open source developments support the development of the cellular-based ecosystem.

This activity shall identify such open source SDR initiatives, and propose to complement such initiatives with a satellite-related component of New Radio.

A number of SDR boards are currently capable of supporting 4G RAN, be it the UE or eNB. While the first 5G New Radio waveform is specified in Rel-15 already, it has not been implemented yet on commonly available open source SDR platforms. Nearly all available SDR platforms are closed source e.g. Amarisoft. SDR based products or prototypes from big cellular vendors are closed source as well.

There are few open source initiatives available for 3GPP-based systems. Software Radio Systems (SRS), [5]) is one of them, concentrating on LTE developments for eNB and UE.

Based on GNU Radio, there is the project called “gr-lte” ([6]). This project aims to provide a modular environment for an LTE downlink receiver (UE-side). “gr-lte” provides blocks to synchronize to a LTE downlink signal. It performs OFDM operation to operate in the frequency domain and provides a channel estimator. Gr-lte seems to concentrate on LTE and no public information is available on activities for New Radio developments.

Besides these two open-source projects aiming mostly on the UE-side, there is OpenAirInterface [7], which already provides implementation of various features from different LTE Releases on eNB- and UE-side.  Members of the OpenAirInterface Software Alliance (OSA) contribute to the Open Air Interface (OAI) open source software. Currently, the OAI 5G New Radio software stack is under development, for gNB and UE and OAI seems to be the most promising SDR platform for New Radio adapted for satellite.

Deliverables and Output

• Real time prototype for New Radio adapted to operate over satellite (GEO as first priority and LEO as second priority)
• Contributions to open source project(s) like OpenAirInterface are considered as a plus.
• Technical note on findings.

Duration and schedule (mid term milestone and review, if applicable)

The duration of the activity shall not exceed 9 month, with one intermediate review.

Maximum budget available for the activity

The budget of this activity shall not exceed 60000 €.

References and related activities

[1] 3GPP TR 38.811 “Study on New Radio (NR) to support non terrestrial networks (Release 15)”, V15.0.0, 2018-06

[2] 3GPP RP-190710 “Study on solutions for NR to support non-terrestrial networks (NTN)”, Thales, 3GPP TSG RAN meeting #83, Shenzhen, China, March 18-21, 2019

[3] 3GPP TR 38.821 “Solutions for NR to support non-terrestrial networks (NTN) (Release 16)”, Draft v0.6.0, 2019-04

[4] ITU-R M.2047-0 “Detailed specifications of the satellite radio interfaces of International Mobile Telecommunications- Advanced (IMT-Advanced)”, 2013-12

[5] www.softwareradiosystems.com

[6] https://github.com/kit-cel/gr-lte

[7] OpenAirInterface Software Alliance, www.openairinterface.org

[8] 5G-METEORS 1st Open Call Topic 2 “Realtime SDR – 5G NR over satellite – higher layers (PDCP/RLC)”

Proposal Submission

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