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5G • 5G-Advanced (Rel-18)

SBFD In-Band Relay

Integrated Access and Backhaul (IAB) Full Duplex Relaying

Applies SBFD self-interference cancellation to IAB relay nodes, allowing simultaneous wireless backhaul reception and mobile access transmission on the same carrier.

Technical Explanation

Legacy Integrated Access and Backhaul (IAB) nodes in Rel-16/17 must alternate between communicating with the parent donor base station (backhaul) and serving local mobile users (access), cutting effective throughput in half. SBFD IAB relays employ self-interference cancellation to backhaul and serve users simultaneously, doubling relay spectral efficiency.

Key Functions

  • Enables simultaneous wireless backhaul and user access on a single carrier frequency
  • Doubles the throughput efficiency of Integrated Access and Backhaul (IAB) nodes
  • Eliminates half-duplex scheduling bottlenecks across multi-hop relay topologies
  • Significantly reduces fiber rollout costs in dense urban millimeter wave extensions
Specifications
3GPP TR 38.858, TS 38.401 (Rel-18)
Interfaces
UuF1* (IAB)
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