ETSI TS 103 175 V1.1.1 (2015-06)

ETSI TS 103 175 V1.1.1 (2015-06)






TECHNICAL SPECIFICATION
Intelligent Transport Systems (ITS);
Cross Layer DCC Management Entity
for operation in the ITS G5A and ITS G5B medium

---------------------- Page: 1 ----------------------
2 ETSI TS 103 175 V1.1.1 (2015-06)



Reference
DTS/ITS-0020046
Keywords
ITS, Spectral Management
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2015.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 ETSI TS 103 175 V1.1.1 (2015-06)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Symbols . 9
3.3 Abbreviations . 9
4 Introduction . 10
5 DCC architecture . 11
5.1 Overview . 11
5.2 DCC_ACC . 11
5.3 DCC_NET . 12
5.4 DCC_FAC . 12
5.5 DCC_CROSS . 12
6 DCC management entity . 12
6.1 Overview . 12
6.2 DCC parameter evaluation . 13
6.3 DCC_CROSS_Access . 15
6.4 DCC_CROSS_Net . 16
6.5 DCC_CROSS_Facilities . 16
7 DCC limits specification . 17
7.1 Overview . 17
7.2 Requirements . 17
8 Interfaces . 18
8.1 Overview . 18
8.2 Interface (1) with DCC_ACC (MI SAP) . 18
8.2.1 MI-GET.request . 18
8.2.1.1 Function . 18
8.2.1.2 Semantics . 19
8.2.2 MI-GET.confirm . 19
8.2.2.1 Function . 19
8.2.2.2 Semantics . 19
8.2.3 MI-SET.request . 19
8.2.3.1 Function . 19
8.2.3.2 Semantics . 20
8.2.4 MI-SET.confirm . 20
8.2.4.1 Function . 20
8.2.4.2 Semantics . 20
8.2.5 DCC Parameters at the MI-SAP . 21
8.3 Interface (2) with DCC_NET (MN SAP) . 21
8.3.1 MN-GET.request . 21
8.3.1.1 Function . 21
8.3.1.2 Semantics . 21
8.3.2 MN-GET.confirm . 22
8.3.2.1 Function . 22
8.3.2.2 Semantics . 22
8.3.3 MN-SET.request . 22
8.3.3.1 Function . 22
ETSI

---------------------- Page: 3 ----------------------
4 ETSI TS 103 175 V1.1.1 (2015-06)
8.3.3.2 Semantics . 22
8.3.4 MN-SET.confirm . 22
8.3.4.1 Function . 22
8.3.4.2 Semantics . 23
8.3.5 DCC Parameters at the MN-SAP . 23
8.4 Interface (3) with DCC_FAC (MF SAP) . 24
8.4.1 MF-SET.request . 24
8.4.1.1 Function . 24
8.4.1.2 Semantics . 24
8.4.2 MF-SET.confirm . 24
8.4.2.1 Function . 24
8.4.2.2 Semantics . 24
8.4.3 DCC Parameters at the MF-SAP . 25
9 Test procedures . 25
9.1 Introduction . 25
9.2 General Test requirements . 26
9.3 Test case 1: Homogeneous ITS traffic, energy threshold test . 27
9.4 Test case 2: Homogeneous ITS traffic, header decoding test . 28
9.5 Test case 3: Sensitivity threshold correction . 28
9.6 Test case 4: DCC stability . 28
Annex A (informative): List of requirements . 30
A.1 Introduction . 30
A.2 Requirements . 30
Annex B (informative): Other DCC entities . 32
B.1 Introduction . 32
B.2 DCC_ACC . 32
B.3 DCC_NET . 32
B.4 DCC_FAC . 33
Annex C (informative): DCC algorithms capable of satisfying testable limits . 34
C.1 Introduction . 34
C.2 State-Based Reactive DCC . 34
C.3 Linear Adaptive DCC . 35
History . 36

ETSI

---------------------- Page: 4 ----------------------
5 ETSI TS 103 175 V1.1.1 (2015-06)
Intellectual Property Rights
IPRs essential or potentially essential to the present document 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 (http://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.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Intelligent Transport Systems
(ITS).
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

---------------------- Page: 5 ----------------------
6 ETSI TS 103 175 V1.1.1 (2015-06)
1 Scope
The present document specifies the functionality of the decentralized congestion control (DCC) entity residing in the
management plane for the ITS-G5A, ITS-G5B, and ITS-G5D radio interfaces, collectively known as the 5 GHz ITS
frequency band.
The purpose of the DCC operation is to evaluate the load of the active radio channels and to optimize the radio channel
usage by managing the ITS-S DCC parameters. Another purpose is to keep track and help the exchange of DCC
parameters which cannot be conveyed via the data plane between the different layers.
The present document specifies:
• The necessary support functions of DCC that needs to be in the management plane, i.e. cross-layer DCC
operations.
• The required interface parameters between the DCC management entity and the DCC entities in the facilities,
the networking & transport and the access layers.
• The testing procedures and corresponding test cases.
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] IEEE 802.11-2012: "IEEE Standard for Information technology -- Telecommunications and
information exchange between systems Local and metropolitan area networks -- Specific
requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
[2] ETSI TS 102 687: "Intelligent Transport Systems (ITS); Decentralized Congestion Control
Mechanisms for Intelligent Transport Systems operating in the 5 GHz range; Access layer part".
[3] ETSI EN 302 636-4-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and
point-to-multipoint communications; Sub-part 1: Media-Independent Functionality".
[4] ETSI TS 102 636-4-2: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 2: Media-dependent functionalities for ITS-G5".
[5] ETSI TS 102 723-1: "Intelligent Transport Systems (ITS); OSI cross-layer topics;
Part 1: Architecture and addressing schemes".
[6] ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".
[7] ETSI EN 302 663: "Intelligent Transport Systems (ITS); Access layer specification for Intelligent
Transport Systems operating in the 5 GHz frequency band".
[8] ETSI EN 302 571: "Intelligent Transport Systems (ITS); Radiocommunications equipment
operating in the 5 855 MHz to 5 925 MHz frequency band; Harmonized EN covering the essential
requirements of article 3.2 of the R&TTE Directive".
ETSI

---------------------- Page: 6 ----------------------
7 ETSI TS 103 175 V1.1.1 (2015-06)
[9] ETSI TS 102 792: "Intelligent Transport Systems (ITS); Mitigation techniques to avoid
interference between European CEN Dedicated Short Range Communication (CEN DSRC)
equipment and Intelligent Transport Systems (ITS) operating in the 5 GHz frequency range".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TR 101 612: "Intelligent Transport Systems (ITS); Cross Layer DCC Management Entity for
operation in the ITS G5A and ITS G5B medium; Report on Cross layer DCC algorithms and
performance evaluation".
[i.2] G. Bansal, J. Kenney, and C. Rohrs, "LIMERIC: A Linear Adaptive Message Rate Algorithm for
DSRC Congestion Control", IEEE Trans. Vehicular Technology, Vol. 62, No. 9, Nov. 2013.
[i.3] B. Cheng, M. Gruteser, J. Kenney, G. Bansal, K. Sjoberg, "Performance Evaluation of a Mixed
Vehicular Network with CAM-DCC and LIMERIC Vehicles", Proceedings of the IEEE World of
Wireless, Mobile and Multimedia Networks (IEEE WoWMoM'15), Boston, USA, 2015.
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in IEEE 802.11-2012 [1],
ETSI EN 302 665 [6], ETSI EN 302 663 [7], ETSI EN 302 571 [8] and the following apply:
burst of messages: set of one or more messages that the gatekeeper transfers to the ITS-G5 radio at one time
CBR target value: value used in GN as discriminator for the evaluation of the global CBR
NOTE: In the present document it is set to a fixed value and equal to the congestion threshold C
TH
channel busy ratio: time-dependent value between zero and one (both inclusive) representing the fraction of time that
an individual radio channel used by an ITS-S was busy
NOTE: This is one possible implementation of the channel load metric.
channel resource limit: maximum amount of available resources of an individual radio channel used by an ITS-S
NOTE: It corresponds to a trade-off between the maximum usage of the channel for periodic safety-related
messages, maximizing the performance of the ITS-G5 technology and allowing any event-based
emergency packet to be reliably transmitted.
chipset channel load: chipset data type that the DCC_ACC entity will transform into a local channel specific CBR
value
cross-layer DCC: cooperation mechanisms based on entities distributed over several layers of the protocol stack which
jointly work together to fulfil the operational requirements of DCC
DCC_ACC: DCC entity located at the Access Layer that acts as a gatekeeper and also provides the local CBR values
for all ITS-G5 radio channels used by a certain ITS-S
DCC_CROSS: DCC cross-layer entity located in the management plane
DCC_CROSS_Access: function in the DCC_CROSS entity that exchanges DCC control parameters with DCC_ACC
ETSI

---------------------- Page: 7 ----------------------
8 ETSI TS 103 175 V1.1.1 (2015-06)
DCC_CROSS_Facilities: function in the DCC_CROSS entity that provides DCC control parameters to the facilities
layer and to the applications
DCC_CROSS_Net: function in the DCC_CROSS entity that provides DCC channel resources parameters to the
networking and transport layer
DCC_FAC: DCC entity located at the facilities layer
DCC fairness: concept where any ITS-S under the same channel conditions has an equal opportunity of accessing the
radio channel for periodic messages, while maintaining a channel access margin to always allow the exchange of
safety-critical event-based messages
DCC flow control: function that retrieves the messages from the DCC queues according to their priorities and transfers
them for transmission to the ITS-G5 radio interface
DCC flow control parameters: DCC parameters generated by the DCC_CROSS_Access that indicate to the DCC flow
control the amount of available resources available for transmission on the radio
DCC_NET: DCC entity located in the networking & transport layer
DCC parameter evaluation: function that takes the local CBR and the global DCC RX parameters as input and
evaluates them to obtain the internal DCC parameters and the global DCC TX parameters
DCC power control: optional function that sets the ITS-G5 TX power level according to the DCC power control
parameters per radio channel
DCC power control parameters: DCC parameters generated by the DCC_CROSS_Access function to set the ITS-G5
TX power level limits per radio channel
DCC prioritization: function that routes messages per channel to DCC queues according to the IEEE 802.11 [1]
EDCA access category indicated in the traffic class field
DCC queues: set of buffer space in the DCC_ACC entity in the access layer that temporarily stores the transmission
requests per given radio channel sorted according to their priority and time of arrival
NOTE: A DCC queue retains a message, if a message in a DCC queue with higher priority is present.
decentralized congestion control: set of mechanisms for ITS-S to maintain network stability, throughput efficiency
and fair resource allocation to ITS-S using ITS-G5 access technology
global channel busy ratio: maximum value of the local channel busy ratio, the 1-hop channel busy ratio and the 2-hop
channel busy ratio for a given radio channel
NOTE: The evaluation of the global channel busy ratio, the 1-hop channel busy ratio and the 2-hop channel busy
ratio is specified in ETSI TS 102 636-4-2 [4].
global DCC RX parameters: DCC parameters received from neighbouring ITS-S (e.g. their local CBR measurement)
and locally determined parameters (e.g. number of neighbours) that are used to derive the currently available channel
resources and the global DCC TX parameters
NOTE: These parameters comprehend the basic metrics to derive the current level of resource usage in order to
classify the congestion. Metrics based on local knowledge are used in a first step, such as the Channel
Busy Ratio (CBR) and the number of neighbouring ITS-S. To avoid channel congestion, it is appropriate
to also use cooperatively determined metrics that can be retrieved by exchanging the local metrics.
global DCC TX parameters: DCC parameters per given radio channel broadcasted to neighbouring ITS-S using the
same channel
idle time: time interval between the end of transmission of a first burst and the start of transmission of the next burst by
the ego ITS-S on a given radio channel, considering the inter-frame spacing and inter-leaving transmissions from other
senders
ETSI

---------------------- Page: 8 ----------------------
9 ETSI TS 103 175 V1.1.1 (2015-06)
internal DCC parameters: management parameters that are used to disseminate the DCC parameter evaluation result
to DCC_CROSS_Facilities, to DCC_CROSS_Net and to DCC_CROSS_Access
NOTE: Internal DCC parameters are derived by the DCC parameter evaluation function based on the global DCC
RX parameters and the local CBR value. These parameters define how much channel resources an ITS-S
is allowed to use on each individual radio channel used by the ITS-S.
inter-reception rate: receiver-based metric representing the time between the successful reception of two messages
from the same ITS-S on the same given radio channel
NOTE: If the receiver knows the time between two CAM messages, the inter-reception rate indicates message
losses impacting the ITS-S safety applications.
ITS-G5A: frequency band ranging from 5 875 MHz to 5 905 MHz
ITS-G5B: frequency band ranging from 5 855 MHz to 5 875 MHz
ITS-G5D: frequency band ranging from 5 905 MHz to 5 925 MHz
local channel busy ratio: time-dependent value between zero and one (both inclusive), representing the channel busy
ratio (CBR) as perceived locally by a specific ITS-S for each individual radio channel
message generation parameters: parameters that inform the components in the facilities layer and in the applications
layer about the available channel resources
transmission duration: total time during which the ITS-S own messages are sent on the target radio channel as a burst,
not considering the inter-frame spacing or inter-leaving transmissions from other senders
NOTE: It is also considered to be the transmit duration for the DCC flow control function.
transmit ratio: contri
...