TechWindo

3GPP introduced specific bands for Non-Terrestrial Networks (NTN) to support 5G NR over satellites. These bands are optimized for Mobile Satellite Services (MSS) and Feeder Links.

1. n255 – S-band

• Frequency Range:
  • Uplink (UE → Satellite): 1980 MHz – 2010 MHz
  • Downlink (Satellite → UE): 2170 MHz – 2200 MHz
• Duplex Mode: FDD
• Use Case:
  • Direct UE-to-satellite connectivity for mobile broadband.
  • Common for LEO and GEO satellites.
• Advantages:
  • Good propagation characteristics.
  • Moderate antenna size for UE.

2. n256 – L-band

• Frequency Range:
  • Downlink (Satellite → UE): 1525 MHz – 1559 MHz
  • Uplink (UE → Satellite): 1626.5 MHz – 1660.5 MHz
• Duplex Mode: FDD
• Use Case:
  • MSS services (voice, messaging, IoT).
  • Ideal for NTN because of low attenuation and better penetration.
• Advantages:
  • Excellent coverage and penetration.
  • Smaller bandwidth compared to S-band.

Feeder Link Bands

For connecting satellite ↔ ground gateway, higher frequency bands are used:

• Ka-band: ~27.5–31 GHz (uplink), 17.7–21.2 GHz (downlink)
• Ku-band: ~14 GHz uplink, ~11 GHz downlink

Key Points

• Both n255 and n256 are FDD bands.
• Designed for direct UE-to-satellite links in NTN.
• Support mobility, IoT, and broadband use cases.