What is PDCP sequence number in LTE?

PDCP is located in the Radio Protocol Stack in the UMTS/LTE/5G air interface on top of the RLC layer. PDCP provides its services to the RRC and user plane upper layers , e.g. IP at the UE or to the relay at the base station.

PDCP stands for Packet Data Convergence Protocol . It is a layer of 5G NR radio protocol stack. It is placed top of the RLC Layer and below of the SDAP layer(for user plane) or RRC layer (for control plane) in the Radio Protocol Stack in 5G NR. Due to header compression functionality, it is called as convergence …5 Oca 2022

i) Data coming into PDCP first go through “Sequence Numbering” Procedure. It means that PDCP add “Sequence Number” to each of incoming data block . Once it add ‘Sequence Number’, it has to manage the number.