Description
The objective is to carry out an assessment of the NTN deployment of the 5G NR air interface in TDD mode and identification of technology gaps and constraints. Develop a software testbed implementing and testing the scenario.Improve the overall spectrum utilisation by up to 50% when using Time Division Duplex communication as per 3GPP standard.The 3GPP has specified for Non-Terrestrial Networks (NTN) the n255 and n256 bands, both operating in Frequency Division Duplex (FDD) mode and allocated at L- and S-band. Enabling Time Division Duplex (TDD) communications could further improve the overall spectrum utilisation in Frequency Range 1 (FR1). In addition, this could support the prospective of a unified NTN-TN scenario where the satellite components may dynamically assist terrestrial stations (e.g., in TDD communications with handheld operating at C-band). To pursue this objective, the NTN capability to support the TDD operations of the 5G NR needs to be assessed in detail, this shall include: - a coexistence study of MSS/FSS services and5G TDD transmissions from space in FR1;- the assessment of the round-trip time and mobility (doppler, variable delay) effects on the radio interface efficiency, evaluating whether LEO and/or MEO based accesses in FR1 TDD can be employed (new solutions to supportTDD NTN on the 5G PHY and MAC layer may be required);-the technological constraints coming from the space segment (e.g., digital processor, active antenna) limiting the actual performances of such system scenario.This activity is a system-level assessment of the 5G NTN operating in TDD mode providing a feasibility and performance analysis; PHY and MAC improvements on the 5G NTN stack shall be proposed. In addition, a software simulator implementing and testing the scenario shall be developed.