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SDAP QoS Flow Mapping

QoS Flow to DRB Mapping

Rule set within the SDAP layer mapping 5G Core QoS Flows (identified by QFI) to radio data bearers (DRBs).

Technical Explanation

In 5G NR, QoS is managed per-flow rather than per-bearer. The SDAP layer maps incoming 5GC QoS Flows into Data Radio Bearers (DRBs) configured over the air interface. Multiple QoS Flows with compatible delay and loss characteristics can be multiplexed into a single DRB to optimize radio resources.

Key Functions

  • Maps 5G Core QoS Flows (QFIs) into over-the-air Data Radio Bearers (DRBs)
  • Enables many-to-one mapping of QoS Flows to radio bearers
  • Configured via RRC and dynamically updated via Reflective QoS
Specifications
3GPP TS 37.324
Interfaces
Uu

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