5G • RAN
PDCP Control PDU
PDCP Status Report Control PDU
Control packet exchanged between peer PDCP entities during handover to coordinate lossless data forwarding.
Technical Explanation
During handover, the UE and target gNodeB exchange PDCP Control PDUs (Status Reports). The report contains First Missing COUNT (FMC) and a bitmap indicating which packets were received successfully. The transmitter uses this to retransmit only missing packets, achieving completely seamless, lossless handover.
Key Functions
- Coordinates lossless packet retransmission during mobility handovers
- Identifies First Missing COUNT (FMC) and subsequent packet reception bitmap
- Exchanges RoHC feedback for header decompressor synchronization
Specifications
3GPP TS 38.323
Interfaces
Uu
Related 5G Concepts
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