Service Data Adaptation Protocol (SDAP)
SDAP is the 5G radio protocol layer that maps quality-of-service flows onto data radio bearers.
What is Service Data Adaptation Protocol (SDAP)?
SDAP was introduced in 5G NR and sits above PDCP. It tags packets with QoS flow identifiers and sends each flow to a suitable DRB, so that it gets the right treatment over the air.