ETSI TS 138 323 V16.3.0 (2021-04)

5G; NR; Packet Data Convergence Protocol (PDCP) specification (3GPP TS 38.323 version 16.3.0 Release 16)

RTS/TSGR-0238323vg30

General Information

• Status: Not Published
• Technical Committee: 3GPP RAN 2 - Radio layer 2 specification and Radio layer 3 RR specification
• Current Stage: 12 - Completion
• Completion Date: 16-Apr-2021

Standards Content (Sample)

ETSI TS 138 323 V16.3.0 (2021-04)






TECHNICAL SPECIFICATION
5G;
NR;
Packet Data Convergence Protocol (PDCP) specification
(3GPP TS 38.323 version 16.3.0 Release 16)

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3GPP TS 38.323 version 16.3.0 Release 16 1 ETSI TS 138 323 V16.3.0 (2021-04)

Reference
RTS/TSGR-0238323vg30
Keywords
5G

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ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 2 ETSI TS 138 323 V16.3.0 (2021-04)
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ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 3 ETSI TS 138 323 V16.3.0 (2021-04)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 General . 8
4.1 Introduction . 8
4.2 Architecture . 8
4.2.1 PDCP structure . 8
4.2.2 PDCP entities . 9
4.3 Services . 10
4.3.1 Services provided to upper layers . 10
4.3.2 Services expected from lower layers . 10
4.4 Functions . 11
5 Procedures . 11
5.1 PDCP entity handling . 11
5.1.1 PDCP entity establishment . 11
5.1.2 PDCP entity re-establishment . 11
5.1.3 PDCP entity release . 13
5.1.4 PDCP entity suspend . 13
5.1.5 PDCP entity reconfiguration . 13
5.2 Data transfer . 14
5.2.1 Transmit operation . 14
5.2.2 Receive operation . 15
5.2.2.1 Actions when a PDCP Data PDU is received from lower layers . 15
5.2.2.2 Actions when a t-Reordering expires . 16
5.2.2.3 Actions when the value of t-Reordering is reconfigured . 17
5.2.3 Sidelink transmit operation . 17
5.2.4 Sidelink receive operation . 17
5.3 SDU discard . 17
5.4 Status reporting . 17
5.4.1 Transmit operation . 17
5.4.2 Receive operation . 18
5.5 Data recovery . 18
5.6 Data volume calculation . 18
5.7 Robust header compression and decompression . 19
5.7.1 Supported header compression protocols and profiles . 19
5.7.2 Configuration of ROHC . 20
5.7.3 Protocol parameters . 20
5.7.4 Header compression using ROHC . 20
5.7.5 Header decompression using ROHC . 21
5.7.6 PDCP Control PDU for interspersed ROHC feedback . 21
5.7.6.1 Transmit Operation . 21
5.7.6.2 Receive Operation . 21
5.8 Ciphering and deciphering . 21
5.9 Integrity protection and verification . 22
5.10 Handling of unknown, unforeseen, and erroneous protocol data . 23
5.11 PDCP duplication . 23
5.11.1 Activation/Deactivation of PDCP duplication . 23
5.11.2 Duplicate PDU discard . 24
5.12 Ethernet header compression and decompression . 24
ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 4 ETSI TS 138 323 V16.3.0 (2021-04)
5.12.1 Supported header compression protocols . 24
5.12.2 Configuration of EHC . 24
5.12.3 Protocol parameters . 24
5.12.4 Header compression using EHC . 24
5.12.5 Header decompression using EHC . 25
5.12.6 PDCP Control PDU for EHC feedback . 25
5.12.6.1 Transmit Operation . 25
5.12.6.2 Receive Operation . 25
5.12.7 Simultaneous configuration of ROHC and EHC . 25
5.13 Uplink data switching . 25
6 Protocol data units, formats, and parameters . 26
6.1 Protocol data units . 26
6.1.1 Data PDU . 26
6.1.2 Control PDU . 26
6.2 Formats . 26
6.2.1 General . 26
6.2.2 Data PDU . 27
6.2.2.1 Data PDU for SRBs . 27
6.2.2.2 Data PDU for DRBs with 12 bits PDCP SN . 27
6.2.2.3 Data PDU for DRBs with 18 bits PDCP SN . 28
6.2.2.4 Data PDU for sidelink DRBs for groupcast and broadcast and for the sidelink SRB0 . 28
6.2.2.5 Data PDU for sidelink SRBs for unicast . 29
6.2.2.6 Data PDU for sidelink DRBs for unicast with 12 bits PDCP SN . 29
6.2.2.7 Data PDU for sidelink DRBs for unicast with 18 bits PDCP SN . 30
6.2.3 Control PDU . 31
6.2.3.1 Control PDU for PDCP status report . 31
6.2.3.2 Control PDU for interspersed ROHC feedback . 32
6.2.3.3 Control PDU for EHC feedback. 32
6.3 Parameters . 32
6.3.1 General . 32
6.3.2 PDCP SN . 32
6.3.3 Data . 33
6.3.4 MAC-I . 33
6.3.5 COUNT . 33
6.3.6 R . 33
6.3.7 D/C. 33
6.3.8 PDU type . 34
6.3.9 FMC . 34
6.3.10 Bitmap . 34
6.3.11 Interspersed ROHC feedback . 34
6.3.12 SDU Type . 34
6.3.13 K ID . 34
NRP-sess
7 State variables, constants, and timers . 35
7.1 State variables . 35
7.2 Constants . 35
7.3 Timers . 36
Annex A (normative): Ethernet Header Compression (EHC) protocol . 37
A.1 EHC principle . 37
A.2 EHC packet format and parameters . 38
A.2.1 EHC packet format . 38
A.2.1.1 EHC Full Header packet and EHC Compressed Header packet . 38
A.2.1.2 EHC feedback packet . 39
A.2.2 Parameters. 39
A.2.2.1 F/C. 39
A.2.2.2 CID . 39
Annex B (informative): Change history . 40
History . 41

ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 5 ETSI TS 138 323 V16.3.0 (2021-04)
Foreword
This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 6 ETSI TS 138 323 V16.3.0 (2021-04)
1 Scope
The present document provides the description of the Packet Data Convergence Protocol (PDCP).

2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 38.300: "NG Radio Access Network; Overall description".
[3] 3GPP TS 38.331: "NR Radio Resource Control (RRC); Protocol Specification".
[4] 3GPP TS 38.321: "NR Medium Access Control (MAC) protocol specification".
[5] 3GPP TS 38.322: "NR Radio Link Control (RLC) protocol specification".
[6] 3GPP TS 33.501: "Security Architecture and Procedures for 5G System ".
[7] IETF RFC 5795: "The RObust Header Compression (ROHC) Framework".
[8] IETF RFC 3095: "RObust Header Compression (ROHC): Framework and four profiles: RTP,
UDP, ESP and uncompressed".
[9] IETF RFC 4815: "RObust Header Compression (ROHC): Corrections and Clarifications to RFC
3095".
[10] IETF RFC 6846: "RObust Header Compression (ROHC): A Profile for TCP/IP (ROHC-TCP)".
[11] IETF RFC 5225: "RObust Header Compression (ROHC) Version 2: Profiles for RTP, UDP, IP,
ESP and UDP Lite".
[12] 3GPP TS 36.321: "Evolved Universal Terrestrial Radio Access (E-UTRA) Medium Access
Control (MAC) protocol specification".
[13] 3GPP TS 23.287: "Architecture enhancements for 5G System (5GS) to support Vehicle-to-
Everything (V2X) services".
[14] 3GPP TS 33.536: "Security Aspect of 3GPP Support for Advanced V2X Services".
[15] IEEE Standard 802.3™-2018: "Ethernet".
[16] 3GPP TS 24.587: "Vehicle-to-Everything (V2X) services in 5G System (5GS), Stage 3".
ETSI

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3GPP TS 38.323 version 16.3.0 Release 16 7 ETSI TS 138 323 V16.3.0 (2021-04)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A
term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].
AM DRB: a data radio bearer which utilizes RLC AM.
DAPS bearer: a bearer whose radio protocols are located in both the source gNB and the target gNB during DAPS
handover to use both source gNB and target gNB resources.
Non-split bearer: a bearer whose radio protocols are located in either the MgNB or the SgNB to use MgNB or SgNB
resource, respectively.
NR sidelink communication: AS functionality enabling at least V2X communication as defined in TS 23.287 [13],
between two or more nearby UEs, using NR technology but not traversing any network node.
PDCP data volume: the amount of data available for transmission in a PDCP entity.
Split bearer: in dual connectivity, a bearer whose radio protocols are located in both the MgNB and the SgNB to use
both MgNB and SgNB resources.
Split secondary RLC entity: in dual connectivity, the RLC entity other than the primary RLC entity which is
responsible for split bearer operation. If the PDCP entity is associated with two RLC entities, the split secondary RLC
entity is the RLC entity other than the primary RLC entity. If the PDCP entity is associated with more than two RLC
entities, the split secondary RLC entity is configured by upper layers.
UM DRB: a data radio bearer which utilizes RLC UM.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An
abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in
TR 21.905 [1].
AM Acknowledged Mode
CID Context Identifier
DAPS Dual Active Protocol Stack
DRB Data Radio Bearer carrying user plane data
EHC Ethernet Header Compression
gNB NR Node B
HFN Hyper Frame Number
IETF Internet Engineering Task Force
IP Internet Protocol
MAC Medium Access Control
MAC-I Message Authentication Code for Integrity
PDCP Packet Data Convergence Protocol
PDU Protocol Data Unit
RB Radio Bearer
RFC Request For Comments
RLC Radio Link Control
ROHC RObust Header Compression
RRC Radi
...