5G • RAN
SDAP Header
1-Byte SDAP Protocol Header
Compact 8-bit protocol header prepended to user plane data packets carrying QFI, RQI, and RDI flags.
Technical Explanation
The downlink SDAP header contains 1 byte: 1 bit for RQI (Reflective QoS Indicator), 1 bit for RDI (Reflective QoS Indication for DL), and 6 bits for QFI (QoS Flow ID). In the uplink, it carries 1 bit for DC (Data/Control) and 6 bits for QFI, adding minimal protocol overhead.
Key Functions
- Appends minimal 1-byte protocol overhead per user plane packet
- Conveys 6-bit QFI and 1-bit Reflective QoS Indicator (RQI)
- Configurable as present or absent per Data Radio Bearer
Specifications
3GPP TS 37.324
Interfaces
Uu
Related 5G Concepts
Want to memorize 5G concepts like this one?
Study it with SuperMemo SM-2 spaced repetition flashcards.