ETSI TS 136 321 V15.8.0 (2020-01)

ETSI TS 136 321 V15.8.0 (2020-01)






TECHNICAL SPECIFICATION
LTE;
Evolved Universal Terrestrial Radio Access (E-UTRA);
Medium Access Control (MAC) protocol specification
(3GPP TS 36.321 version 15.8.0 Release 15)

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3GPP TS 36.321 version 15.8.0 Release 15 1 ETSI TS 136 321 V15.8.0 (2020-01)



Reference
RTS/TSGR-0236321vf80
Keywords
LTE
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3GPP TS 36.321 version 15.8.0 Release 15 2 ETSI TS 136 321 V15.8.0 (2020-01)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
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ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
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Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found under http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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3GPP TS 36.321 version 15.8.0 Release 15 3 ETSI TS 136 321 V15.8.0 (2020-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 6
1 Scope . 7
2 References . 7
3 Definitions and abbreviations . 8
3.1 Definitions . 8
3.2 Abbreviations . 11
4 General . 12
4.1 Introduction . 12
4.2 MAC architecture . 12
4.2.1 MAC Entities . 12
4.3 Services . 15
4.3.1 Services provided to upper layers . 15
4.3.2 Services expected from physical layer . 15
4.4 Functions . 15
4.5 Channel structure . 16
4.5.1 Transport Channels . 16
4.5.2 Logical Channels . 16
4.5.3 Mapping of Transport Channels to Logical Channels . 17
4.5.3.1 Uplink mapping . 17
4.5.3.2 Downlink mapping . 17
4.5.3.3 Sidelink mapping . 18
5 MAC procedures . 19
5.1 Random Access procedure . 19
5.1.1 Random Access Procedure initialization . 19
5.1.2 Random Access Resource selection . 22
5.1.3 Random Access Preamble transmission . 24
5.1.4 Random Access Response reception. 25
5.1.5 Contention Resolution . 28
5.1.6 Completion of the Random Access procedure . 30
5.2 Maintenance of Uplink Time Alignment . 31
5.3 DL-SCH data transfer . 32
5.3.1 DL Assignment reception . 32
5.3.2 HARQ operation . 34
5.3.2.1 HARQ Entity. 34
5.3.2.2 HARQ process . 35
5.3.3 Disassembly and demultiplexing . 36
5.4 UL-SCH data transfer . 36
5.4.1 UL Grant reception . 36
5.4.2 HARQ operation . 40
5.4.2.1 HARQ entity . 40
5.4.2.2 HARQ process . 43
5.4.3 Multiplexing and assembly . 45
5.4.3.1 Logical channel prioritization . 45
5.4.3.2 Multiplexing of MAC Control Elements and MAC SDUs . 47
5.4.4 Scheduling Request. 47
5.4.5 Buffer Status Reporting . 49
5.4.5a Data Volume and Power Headroom Reporting . 51
5.4.6 Power Headroom Reporting . 51
5.5 PCH reception . 53
5.6 BCH reception . 53
ETSI

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3GPP TS 36.321 version 15.8.0 Release 15 4 ETSI TS 136 321 V15.8.0 (2020-01)
5.7 Discontinuous Reception (DRX) . 54
5.7a Discontinuous Reception (DRX) for SC-PTM . 57
5.8 MAC reconfiguration . 58
5.9 MAC Reset . 58
5.10 Semi-Persistent Scheduling . 59
5.10.1 Downlink . 59
5.10.2 Uplink . 60
5.11 Handling of unknown, unforeseen and erroneous protocol data . 61
5.12 MCH reception . 61
5.13 Activation/Deactivation of SCells . 61
5.14 SL-SCH Data transfer . 63
5.14.1 SL-SCH Data transmission . 63
5.14.1.1 SL Grant reception and SCI transmission . 63
5.14.1.2 Sidelink HARQ operation . 69
5.14.1.2.1 Sidelink HARQ Entity . 69
5.14.1.2.2 Sidelink process . 69
5.14.1.3 Multiplexing and assembly . 70
5.14.1.3.1 Logical channel prioritization . 70
5.14.1.3.2 Multiplexing of MAC SDUs . 71
5.14.1.4 Buffer Status Reporting . 71
5.14.1.5 TX carrier (re-)selection for V2X sidelink communication . 73
5.14.2 SL-SCH Data reception . 74
5.14.2.1 SCI reception. 74
5.14.2.2 Sidelink HARQ operation . 75
5.14.2.2.1 Sidelink HARQ Entity . 75
5.14.2.2.2 Sidelink process . 75
5.14.2.3 Disassembly and demultiplexing . 76
5.15 SL-DCH data transfer . 76
5.15.1 SL-DCH data transmission . 76
5.15.1.1 Resource allocation . 76
5.15.1.2 Sidelink HARQ operation . 76
5.15.1.2.1 Sidelink HARQ Entity . 76
5.15.1.2.2 Sidelink process . 77
5.15.2 SL-DCH data reception . 78
5.15.2.1 Sidelink HARQ operation . 78
5.15.2.1.1 Sidelink HARQ Entity . 78
5.15.2.1.2 Sidelink process . 78
5.16 SL-BCH data transfer . 79
5.16.1 SL-BCH data transmission . 79
5.16.2 SL-BCH data reception . 79
5.17 Data inactivity monitoring . 79
5.18 Recommended Bit Rate . 79
5.19 Activation/Deactivation of CSI-RS resources . 80
5.20 Preallocated uplink grant . 80
5.21 SC-PTM Stop Indication . 80
5.22 Entering Dormant SCell state . 81
5.23 Autonomous Uplink . 82
5.24 Activation/Deactivation of PDCP duplication. 83
6 Protocol Data Units, formats and parameters . 83
6.1 Protocol Data Units . 83
6.1.1 General . 83
6.1.2 MAC PDU (DL-SCH and UL-SCH except transparent MAC and Random Access Response, MCH) . 83
6.1.3 MAC Control Elements . 85
6.1.3.1 Buffer Status Report MAC Control Elements . 85
6.1.3.1a Sidelink BSR MAC Control Elements . 87
6.1.3.2 C-RNTI MAC Control Element . 88
6.1.3.3 DRX Command MAC Control Element . 89
6.1.3.4 UE Contention Resolution Identity MAC Control Element . 89
6.1.3.5 Timing Advance Command MAC Control Element . 89
6.1.3.6 Power Headroom Report MAC Control Element . 90
6.1.3.6a Extended Power Headroom Report MAC Control Elements . 90
ETSI

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3GPP TS 36.321 version 15.8.0 Release 15 5 ETSI TS 136 321 V15.8.0 (2020-01)
6.1.3.6b Dual Connectivity Power Headroom Report MAC Control Element . 93
6.1.3.7 MCH Scheduling Information MAC Control Element . 95
6.1.3.7a Extended MCH Scheduling Information MAC Control Element . 96
6.1.3.8 Activation/Deactivation MAC Control Elements . 97
6.1.3.9 Long DRX Command MAC Control Element . 98
6.1.3.10 Data Volume and Power Headroom Report MAC Control Element . 98
6.1.3.11 SPS confirmation MAC Control Element . 99
6.1.3.12 SC-PTM Stop Indication MAC Control Element . 99
6.1.3.13 Recommended bit rate MAC Control Element . 100
6.1.3.14 Activation/Deactivation of CSI-RS resources MAC Control Element . 101
6.1.3.15 Hibernation MAC Control Elements . 102
6.1.3.16 AUL confirmation MAC Control Element . 103
6.1.3.17 PDCP Duplication Activation/Deactivation MAC Control Element . 104
6.1.4 MAC PDU (transparent MAC) . 104
6.1.5 MAC PDU (Random Access Response) . 104
6.1.6 MAC PDU (SL-SCH) . 106
6.2 Formats and parameters . 108
6.2.1 MAC header for DL-SCH, UL-SCH and MCH. 108
6.2.2 MAC header for Random Access Response . 111
6.2.3 MAC payload for Random Access Response . 111
6.2.4 MAC header for SL-SCH . 111
7 Variables and constants . 112
7.1 RNTI values . 112
7.2 Backoff Parameter values . 114
7.3 PRACH Mask Index values. 116
7.4 Subframe_Offset values . 116
7.5 TTI_BUNDLE_SIZE value. 116
7.6 DELTA_PREAMBLE values . 116
7.7 HARQ RTT Timers . 117
7.8 DL_REPETITION_NUMBER value . 119
7.9 UL_REPETITION_NUMBER value . 119
Annex A (normative): Handling of measurement gaps . 120
Annex B (normative): Contention resolution for RACH access . 121
Annex C (informative): Intended UE behaviour for DRX Timers . 124
Annex D (normative): List of CRs Containing Early Implementable Features and
Corrections . 126
Annex E (informative): Change history . 127
History . 136

ETSI

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3GPP TS 36.321 version 15.8.0 Release 15 6 ETSI TS 136 321 V15.8.0 (2020-01)
Foreword
rd
This Technical Specification has been produced by the 3 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 36.321 version 15.8.0 Release 15 7 ETSI TS 136 321 V15.8.0 (2020-01)
1 Scope
The present document specifies the E-UTRA MAC protocol.
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.
...