RAN4 NTN Co-existence

3GPP RAN4 is working on an NTN coexistence study in frequency bands around 2GHz. This involves producing system level simulations with regards to Terrestrial (TN) and Non-Terrestrial Network (NTN) co-existence within adjacent frequency bands. We have modified our fully dynamic system level simulator operating on a packet level resolution for the purpose. Template is implemented by the NTN simulator.

Essential pre-conditions

  • NTN satellite with 1 beam and 1-tier FR3 wrap-around (6 beams generating co-channel interference)

  • TN network with 7 macro sites with 3 sectors each (21 cells total)

  • ACIR region offset: enabled (13 dB)

  • 10 UEs per TN cell area = 210 in total

  • 50 NTN UEs on the edge of TN; Isolation distance of 2 * ISD in Urban scenarios

  • TN interference scaling enabled (in cases where TN UL is the aggressor)

  • Full buffer traffic

Configurable options

  • NTN orbit & TN scenario combination

    • LEO 600 & Urban (/scaled)

    • LEO 600 & Rural (/scaled)

    • LEO 1200 & Urban (/scaled)

    • LEO 1200 & Rural (/scaled)

    • GEO & Urban (/scaled)

    • GEO & Rural (/scaled)

  • Adjacent Channel Interference Ratio (ACIR)

    • Off

    • 12, 14, ..., 38, 40 dB (15 options)

RAN4 Templates

All the templates are identical to each other except on the Adjacent Channel Interference (ACI) configuration. Other channels do not interfere each others.

ACIR range. Additional 13 dB attenuation for 2/3 of the bandwidth (=13 dB ACIR range) where as the closest 1/3 interfered bandwidth get the nominal ACIR value.

Scaling factor. The simulated TN network does not cover the whole beam but caused interference has been scaled up assuming there are TN cells on full NTN beam coverage area. Assuming 20% activity factor.

RAN4-SC1

Aggressor TN DL. Victim NTN DL. Constant ACIR values.

RAN4-SC2

Aggressor TN UL. Victim NTN UL. ACIR range. ACI scaling enabled.

RAN4-SC3

Aggressor NTN DL. Victim TN DL. Constant ACIR values.

RAN4-SC4

Aggressor NTN UL. Victim TN UL. ACIR range.

RAN4-SC5

Aggressor NTN UL. Victim TN DL. ACIR range.

RAN4-SC6

Aggressor TN DL. Victim NTN UL. Constant ACIR values. ACI scaling enabled.


Scenario aggressor/victim configurations

ACIR range

Urban TN configuration with NTN users on outside ring

    • In urban TN scenarios the NTN UE ring and TN outer edge isolation distance is 2 * ISD.

Rural TN configuration with NTN users on outside ring

    • In rural TN scenarios there is no isolation distance between NTN user ring and TN network edge

References

[1] R4-2120671, Simulation assumptions for NTN co-existence study, Samsung, CATT, 3GPP TSG-RAN WG4 Meeting # 101-e, November, 2021.