Terminology » Difference between Service Link vs Feeder Link

Difference between Service Link vs Feeder Link

5g ntn 5g ntn satellite communication

These are the two primary communication links in 5G Non-Terrestrial Network (NTN) architecture viz. service link and feeder link. These two links are fundamental in NTN based 5G communication, as they describe how signals travel between users, satellites, and gateway stations.

  • The service link is the radio interface between the satellite and the User Equipment (UE) for example, a smartphone, IoT device or vehicle terminal. It is also known by “User Link”.
  • It is the link through which end users actually access 5G NTN services, such as voice, data or IoT connectivity.
  • Operates in S-band, Ku-band or Ka-band as per satellite type (LEO, MEO, GEO) to provide wide area coverage.
  • The service link handles both uplink (i.e. UE to satellite) and downlink (satellite to UE) communication.
  • This link connects the satellite to the ground gateway station (i.e. NTN Gateway or NCC-network control center), which then connects to the 5G core network (5GC).
  • It carries aggregated data between core network (through gateway) and the satellite.
  • This link is not directly accessible to users. It is purely used as network infrastructure.
  • Operates in higher bands e.g. Ka-band, Q/V band to offer higher throughput and to reduce interference with user bands.

5G NTN Service vs Feeder Link

Key differences

AspectService LinkFeeder Link
DefinitionRadio Link between satellite & UE (User Equipment)Radio Link between Satellite & Ground Gateway Station
PurposeProvides user access to 5G NTN servicesConnects satellite to the core network via the gateway
Data TypeUser data and control signaling to/from end usersAggregated user traffic and network control signaling
BandsS, Ku, Ka bandsKa, Q, V bands
Access by userDirectly accessed by the userNot accessible by the user
Function in the networkAir interface for userActs as trunk line between satellite & core
Example Use caseSatellite providing mobile connectivity to a ship or vehicleSatellite communicating with a network control center on Earth

Summary: The service link connects the user to the satellite; the feeder link connects the satellite to the ground network.