Packet Data Convergence Protocol

In Release 15, the PDCP function introduced several key features including PDCP duplication for increased reliability, a PDCP suspend/resume procedure, and support for Robust Header Compression (ROHC) for Mission Critical and V2X services. It also added clarifications and corrections for handling split bearers, LWA bearers, and the notification of PDCP sequence number length changes. Furthermore, the release specified the delivery of stored PDCP SDUs for UM DRBs during re-establishment and defined the inclusion of RLC mode information for PDCP transfer.

• Introduction of PDCP duplication TS 38.323CR0009
• Use of ARP priority level in addition to QCI for packet handling TS 23.401CR3359
• Addition of a note that input-packets / output-packets are not reported in SGi signalling with CUPS TS 29.061CR0500
• RoHC support for Mission Critical services over MBMS TS 36.300CR1116
• Inclusion of Maximum Number of PDCP SDUs per TTI for DL Categories 22-26 TS 36.306CR1736
• Deliver stored PDCP SDUs for UM DRB at PDCP re-establishment TS 36.323CR0241

+ 39 more changes

In Release 16, the PDCP function was enhanced with new capabilities for QoS monitoring, including accumulated packet delay estimation and queuing delay measurement. The release also introduced support for Ethernet packet filters within the Traffic Flow Template (TFT) and allowed for a PDCP version change without requiring a handover. Furthermore, it included corrections and operational clarifications for scenarios such as PDCP re-establishment when using t-Reordering and for duplication in Industrial IoT (IIoT) contexts.

• Accumulated packet delay estimation for QoS monitoring and division of PDB TS 23.725CR0028
• Introducing EHC in LTE PDCP TS 36.323CR0278
• Ethernet packet filters in TFT TS 23.401CR3512
• Allowing PDCP version change without handover TS 36.306CR1754
• LTE PDCP corrections for NR IIOT TS 36.323CR0286
• Correction for PDCP status report TS 36.323CR0287

+ 21 more changes

In Release 17, the key new feature for PDCP was the introduction of support for User Plane IP in EPC-connected architectures using NR PDCP. This enhancement was accompanied by various corrections and clarifications for other PDCP-related functions, including aspects for sidelink relay, multicast/broadcast service (MBS), and Layer 2 UE-to-Network relay. The release also included specific corrections to PDCP control PDUs and procedures for uplink delay reporting and entity establishment.

• Introducing support of UP IP for EPC connected architectures using NR PDCP TS 36.300CR1353
• Introducing support of UP IP for EPC connected architectures using NR PDCP TS 36.331CR4763
• Introducing support of UP IP for EPC connected architectures using NR PDCP TS 38.323CR0085
• Introducing support of UP IP for EPC connected architectures using NR PDCP TS 38.331CR2904
• Correction on PDCP Control PDU for UDC feedback TS 36.323CR0304
• Correction of references to RRC protocol elements in S1AP TS 36.413CR1908

+ 12 more changes

In Release 18, key PDCP enhancements included the introduction of NR sidelink PDCP duplication to improve reliability for direct device-to-device communication. The release also introduced a PDCP Sequence Number gap reporting mechanism and delivered corrections for the delay critical indication from PDCP to RLC, as well as for PDCP configuration in multicast and dual-connectivity scenarios.

• Updates on 3GPP-Packet-Filter TS 29.061CR0553
• Introduction of NR sidelink PDCP duplication in TS 38.323 TS 38.323CR0126
• Protocol Stack for MTSI UE TS 26.114CR0529
• IANA registration for data channel sub-protocols TS 26.114CR0537
• PDCP SN gap reporting TS 38.323CR0139
• Correction for Delay Critical Indication from PDCP to RLC TS 38.323CR0144

+ 3 more changes

In Release 19, the primary enhancements for PDCP focused on Extended Reality (XR) services, introducing specific XR enhancements and making corrections to the related PDCP specification. The release also included corrections to the PDCP configuration for Signaling Radio Bearers SRB4 and SRB5. Furthermore, the "MOBILE" protocol was added to the standardized inventory list of protocols.

• Introduction of R19 XR enhancements for PDCP spec. TS 38.323CR0149
• Adding MOBILE protocol to inventory list TS 33.938CR0008
• XR PDCP corrections TS 38.323CR0151
• Correction on pdcp-Config for SRB4 and SRB5 TS 38.331CR5586