ISO 24102-5:2013
(Main)Intelligent transport systems — Communications access for land mobiles (CALM) — ITS station management — Part 5: Fast service advertisement protocol (FSAP)
Intelligent transport systems — Communications access for land mobiles (CALM) — ITS station management — Part 5: Fast service advertisement protocol (FSAP)
ISO 24102-5:2013 specifies procedures and data elements in the ITS station management entity and the ITS station facilities layer of the ITS station reference architecture for advertisement of locally available ITS services. These procedures and data elements constitute the "Fast Service Advertisement Protocol" (FSAP).
Systèmes intelligents de transport — Accès aux communications des services mobiles terrestres (CALM) — Gestion des stations ITS — Partie 5: Protocole d'avertissement de service rapide (FSAP)
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 24102-5
First edition
2013-07-01
Intelligent transport systems —
Communications access for land
mobiles (CALM) — ITS station
management —
Part 5:
Fast service advertisement protocol
(FSAP)
Systèmes intelligents de transport — Accès aux communications des
services mobiles terrestres (CALM) — Gestion des stations ITS -- —
Partie 5: Protocole d’avertissement de service rapide (FSAP)
Reference number
ISO 24102-5:2013(E)
©
ISO 2013
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ISO 24102-5:2013(E)
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ii © ISO 2013 – All rights reserved
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ISO 24102-5:2013(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 Requirements . 2
6 Architecture . 3
6.1 ITS communications architecture . 3
6.2 Implementation architecture . 3
6.3 Communication entities . 5
6.4 Communication phases . 5
6.5 SAM frames . 7
6.6 FSAP reference architecture . 8
7 Protocol elements . 9
7.1 Management service access points . 9
7.2 Protocol data units . 9
7.3 Port numbers .11
7.4 ITS application object identifier . .11
8 Protocol procedures .12
8.1 General .12
8.2 Service provider .13
8.3 Service user .15
8.4 Service operation phase .17
8.5 ITS station-internal management communications .17
8.6 Duplicate service detection .17
9 Conformance .18
10 Test methods .18
Annex A (normative) ASN.1 modules .19
Bibliography .25
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ISO 24102-5:2013(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received. www.iso.org/patents.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
The committee responsible for this document is ISO/TC 204, Intelligent transport systems.
ISO 24102 consists of the following parts, under the general title Intelligent transport systems —
Communications access for land mobiles (CALM) — ITS station management:
— Part 1: Local management
— Part 3: Service access points
— Part 4: ITS station-internal management communications
— Part 5: Fast service advertisement protocol (FSAP)
The following parts are under preparation:
— Part 2: Remote management
— Part 6: Path and flow management
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ISO 24102-5:2013(E)
Introduction
This International Standard is part of a family of International Standards for communications access for
land mobiles (CALM). An introduction to the whole set of International Standards is provided in ISO 21217.
This part of ISO 24102 is part 5 of a multipart International Standard which determines the intelligent
transport systems (ITS) station management - fast service advertisement protocol.
The ITS station management entity provides functionality related to the management of communication
protocol layers and the security entity presented in the ITS station reference architecture specified in
ISO 21217 and presented in Figure 1, and in line with the general ITS architecture specified in ISO 21217.
Applications
API
MS
Facilities
NF
Networking &
Transport
IN
Access
Communications
Figure 1 — ITS station reference architecture with named interfaces
ITS station management is specified as a distributed process, where no supervisory entity is employed.
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Management
MI MN MF
SI SN SF
Security
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INTERNATIONAL STANDARD ISO 24102-5:2013(E)
Intelligent transport systems — Communications access
for land mobiles (CALM) — ITS station management —
Part 5:
Fast service advertisement protocol (FSAP)
1 Scope
This part of ISO 24102 specifies procedures and data elements in the ITS station management entity
and the ITS station facilities layer of the ITS station reference architecture for advertisement of locally
available ITS services. These procedures and data elements constitute the “Fast Service Advertisement
Protocol” (FSAP).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 8825-2, Information technology — ASN.1 encoding rules: Specification of Packed Encoding Rules
(PER) — Part 2
ISO 21217, Intelligent transport systems — Communications access for land mobiles (CALM) — Architecture
ISO 21218, Intelligent transport systems — Communications access for land mobiles (CALM) — Access
technology support
ISO 24102-1, Intelligent transport systems — Communications access for land mobiles (CALM) — ITS station
management — Part 1: Local management
ISO 24102-3, Intelligent transport systems — Communications access for land mobiles (CALM) — ITS station
management — Part 3: Service access points
ISO 24102-4, Intelligent transport systems — Communications access for land mobiles (CALM) — ITS station
management — Part 4: Station-internal management communications
ETSI TS 102 797-1, Intelligent Transport Systems (ITS); Communications Access for Land Mobiles (CALM);
Test specifications for ITS station management (ISO 24102); Part 1: Protocol Implementation Conformance
Statement (PICS) proforma
ETSI TS 102 797-2, Intelligent Transport Systems (ITS); Communications Access for Land Mobiles (CALM); Test
specifications for ITS station management (ISO 24102); Part 2: Test Suite Structure & Test Purposes (TSS&TP)
ETSI TS 102 797-3, Intelligent Transport Systems (ITS); Communications Access for Land Mobiles (CALM);
Test specifications for ITS station management (ISO 24102); Part 3: Abstract Test Suite (ATS) and partial
PIXIT proforma
3 Terms and definitions
For the purposes of this document, the terms and definitions in ISO 21217 apply.
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ISO 24102-5:2013(E)
4 Abbreviated terms
ctx FSAP message type for service context messages (CTX)
CTX service context message PDU
FMT-ID FSAP Message Type Identifier
FSA fast service advertisement
FSAP FSA protocol
REQN request message PDU, no response message PDU expected
REQRES request or response message PDU out of the set REQW, REQN, RES
REQW request message PDU, response message PDU expected
RES response message PDU, acknowledging a REQW
sam fast message type for service advertisement message (SAM)
SAM service advertisement message PDU
SIP service initialization phase
SOP service operation phase
5 Requirements
The ITS station management includes functionality specified in the various parts of this multipart
International Standard:
1) The functionality of local ITS station management specified in ISO 24102-1.
2) The functionality of remote ITS station management specified in ISO 24102-2.
3) The functionality of management service access points specified in ISO 24102-3.
4) The functionality of ITS station-internal management communications specified in ISO 24102-4.
5) The functionality of the “Fast Service Advertisement Protocol” (FSAP) specified in this part of ISO 24102.
The means to secure the access to management functionality need to be specified within the global
context of ITS security. Details are outside the scope of this part of ISO 24102.
Detailed mandatory requirements are specified in the following clauses of this part of ISO 24102.
— Clause 6 specifies architectural issues related to FSAP.
— Clause 7 specifies protocol elements of FSAP.
— Clause 8 specifies protocol procedures of FSAP.
— Clause 9 specifies conformance declaration.
— Clause 10 specifies test methods.
— Annex A specifies the ASN.1 module for FSAP.
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ISO 24102-5:2013(E)
6 Architecture
6.1 ITS communications architecture
The “Fast Service Advertisement Protocol” (FSAP) is designed in line with the general ITS architecture
specified in ISO 21217.
6.2 Implementation architecture
The “Fast Service Advertisement Protocol” (FSAP) specified in this part of ISO 24102 may support the
implementation architectures introduced in ISO 21217 and illustrated in Figures 2, 3, and 4 with the
peer ITS stations A and B.
NOTE Figures 2, 3, and 4 show the “Fast Network & Transport Protocol” (FNTP) as an example of a suitable
protocol in the networking and transport layer.
Combined ITS-S router / host Combined ITS-S router / host
A B
Applications Applications
Facilities layer Facilities layer
Networking & transport Networking & transport
layer (e.g. FNTP) layer (e.g. FNTP)
Access layer (CIs) Access layer (CIs)
Communication link between ITS-Ss
Figure 2 — Implementation architecture I
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Management
Security
Management
Security
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ISO 24102-5:2013(E)
ITS-S host A
Applications
ITS-S router A
Facilities layer
Networking & transport Networking & transport
layer layer (e.g. FNTP)
Access layer (LAN CI) LAN CI Other CIs
ITS station-internal network A
ITS-S host B
Applications
ITS-S router B
Facilities layer
Networking & transport Networking & transport
layer layer (e.g. FNTP)
Access layer (LAN CI) LAN CI Other CIs
ITS station-internal network B
Figure 3 — Implementation architecture II
ITS-S host A
Applications
ITS-S router A
Facilities layer
Networking & transport Networking & transport
layer layer (e.g. FNTP)
Access layer (LAN CI) LAN CI Other CIs
ITS station-internal network A
Combined ITS-S router / host B
Applications
Facilities layer
Networking & transport
layer (e.g. FNTP)
Access layer
(CIs)
Figure 4 — Implementation architecture III
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Management Management
Management
Management
Security Security
Security
Management Management
Management
Security
Communication link between
ITS-Ss
Security Security
Security
Communication link between ITS-Ss
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ISO 24102-5:2013(E)
6.3 Communication entities
The “Fast Service Advertisement Protocol” (FSAP) distinguishes
— service provider ITS stations, and
— service user ITS stations.
An implementation of an ITS station may simultaneously or sequentially act as a service provider ITS
station and as a service user ITS station.
An instance of any kind of ITS station identified in ISO 21217 may implement the FSAP.
6.4 Communication phases
6.4.1 Overview
In order to allow an instance of an ITS station to offer an ITS service to another instance of an ITS station
by means of an application session, a service initialization phase (SIP) is performed by the FSAP, where
the SIP is based on single-hop ad hoc communication, e.g. applying the FNTP networking and transport
layer protocol specified in [5].
After initialization, the application session is performed during the service operation phase (SOP),
where the SOP may be based on either single-hop ad hoc communication or e.g. IPv6 communication
over any kind of access technology.
During SIP, handover to another access technology and IPv6 may be demanded.
The real-time SIP procedures shall be implemented in an ITS-S router.
SOP communications are between peer ITS-S hosts. Dependent on the implementation, this may require
ITS station-internal forwarding of SOP packets between ITS-S router and ITS-S host.
NOTE The specification of SOP is outside the scope of this part of ISO 24102.
6.4.2 Service initialization phase
The purpose of SIP is to invite a peer ITS station unit by means of a service advertisement message (SAM)
to use an ITS service which is uniquely identified by an ITS application object ID (ITS-AID) specified in [4].
Acceptance of such an invitation finally results in a session where the two peer ITS-S applications
exchange data.
Two operational options of SIP are specified. The distinction originally was motivated by the two ITS
application objects:
[1]
1) ITS application class ; and
2) ITS application.
NOTE A SAM may also contain just a message, which cannot result in a subsequent session.
[1]
Option one, originally designed for ITS application classes (DSRC-like SIP) , is illustrated in Figure 5. SAM
is sent by a service provider ITS station to invite for a service initialization phase. CTX is sent by a
service user ITS station to acknowledge SAM. Successful SIP is given by the first successful REQW or
REQN of the service provider.
NOTE In [1], BST equals SAM, and VST equals CTX.
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ISO 24102-5:2013(E)
Service Provider Service User
SAM
CTX
REQW
RES
REQN
REQN
REQW
RES
Figure 5 — ITS application session with CTX
NOTE The concept of application classes was introduced in [1]. Distinction of classes was done with an
identifier of ASN.1 type DSRCapplicationEntityID. The difference between an ITS application class and an ITS
application is that, for an ITS application object, several contexts exist. Each context itself can be referred to as an
ITS application.
During an SOP
— requests, either with or without an expected response, typically are sent by the service provider but
may also be sent by the service user, and
— responses typically are sent by the service user but may also be sent by the service provider,
depending on the specification of the ITS application.
NOTE 1 The rule on which data are sent by a service provider or by a service user applies strictly for [1]. In
general, for ITS there is no such rule.
NOTE 2 As specified in ISO 21217, the service user and the service client instances of an ITS application are
referred to as ITS-S applications.
[2]
Option two, originally designed for ITS applications (WAVE-like SIP) , is illustrated in Figure 6. SAM
is sent by a service provider ITS sub-system to perform service initialization. Successful SIP is given by
the first successful REQW or REQN of the service user.
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Service
Service
initialization
operation phase
phase
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ISO 24102-5:2013(E)
Service Provider Service User
SAM
REQW
RES
REQN
REQN
REQW
RES
Figure 6 — ITS application session without CTX
During SOP
— requests, either with or without an expected response, typically are sent by the service user but
may also be sent by the service provider, and
— responses typically are sent by the service provider but may also be sent by the service user,
depending on the specification of the ITS application.
NOTE In general, for ITS there is no such strict rule which station type is sending which type of message.
6.4.3 Service operation phase
An ITS service session support is located in the facilities layer. It manages reception and transmission
of session messages, e.g.
— “Request with no response expected” (REQN),
— “Request with response expected” (REQW),
— “Response to a request” (RES)
as illustrated in Figures 5 and 6.
NOTE Details are outside the scope of this part of ISO 24102.
6.5 SAM frames
Depending on the capabilities of the access technology used to transmit SAMs, and depending on system
requirements, the access technology may be accessed either by
— the IN-SAP which is specified in ISO 21218, or
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Service
Service
initialization
operation phase
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ISO 24102-5:2013(E)
— the MI-SAP which is specified in ISO 24102-3.
NOTE Usage of MAC management frames (access via MI-SAP) is specified in [2].
6.6 FSAP reference architecture
The FSAP reference architecture is illustrated in Figure 7.
API
Communications
ITS-S Management Entity ITS-S Facilities Layer
Groupcast
Registration
Handler
Groupcast Manager
Groupcast
Communication
Manager
NF-SAP
ITS-S Networking & Transport Layer
ITS-S Access Layer
Figure 7 — FSAP reference architecture
Management of periodic groupcast for “Fast Service Advertisement Protocol” (FSAP) is specified by
means of three functional entities located in the ITS station (see ISO 21217) i.e.
— “Groupcast registration handler” located in the ITS-S facilities layer,
— “Groupcast communication manager” located in the ITS-S facilities layer,
— “Groupcast manager” located in the ITS-S management entity.
NOTE In case SAMs have to be transmitted in management frames of an access technology, parts of the
functionality of the “Groupcast communication manager” is located in the “ITS-S management entity” of the ITS-S
router used for transmission of SAMs.
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CI Selection Manager
IICP
MF-SAP
MI-SAP MN-SAP
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ISO 24102-5:2013(E)
7 Protocol elements
7.1 Management service access points
NOTE SAPs are functional descriptions which, in many cases, are not implemented as observable interfaces.
Thus, in general, SAPs are not testable. The requirements set up in this part of ISO 24102 with respect to SAPs
thus just mean the functional behaviour rather than a specific implementation. As far as related ASN.1 definitions
are given, these become mandatory as soon as the defined elements become observable, e.g. within a PDU for ITS
station-internal management communications specified in ISO 24102-4.
As specified in this part of ISO 24102, the FSAP shall support functionality of the MF-SAP specified
in ISO 24102-3.
7.2 Protocol data units
7.2.1 Overview
Message protocol data units (PDUs) related to the FSAP port number PORT_SAM identified in [5] are
distinguished by means of a “Fast Message Type Identifier” (FMT-ID). FMT-ID shall distinguish
— “sam” (0): Service advertisement message (SAM) PDU
— “ctx” (1): Service context message (CTX) PDU
FMT-ID is the ASN.1 tag number of the ASN.1 data type FmtID specified in Annex A.
7.2.2 Service advertisement message
The elements of the service advertisement message (SAM) protocol data unit (PDU) identified by FMT-
ID = “sam” (0) are illustrated in Figure 8. The SAM PDU shall be of ASN.1 type SAM specified in Annex A.
Service Advertisement Message (SAM)
Header Body
FMT-ID serverID
Version serviceList channelList ipServList
(sam) (StationID)
Figure 8 — Service advertisement message PDU
Elements of SAM are:
— Header
— FMT-ID = “sam” (0), identifying SAM;
— version number of this part of ISO 24102;
— serverID of the service provider ITS station, which shall be of ASN.1 type StationID specified
in Annex A.
— Body
— serviceList: information on services offered, which are identified by ITS-AID;
— channelList: information on channels to be used for the SOP;
— ipServList: information on services offered, which are identified by ITS-AID, and which will
require IPv6 networking in the SOP. Details of the element ipServList will be provided in a
future version of this part of ISO 24102.
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ISO 24102-5:2013(E)
These elements in the Body consist each of a length field followed by the data as specified in Annex A. At
least either serviceList or ipServList shall have a data length different to zero.
The serviceList shall be of ASN.1 type ServiceList containing one or several entries of ASN.1 type
NonipService as illustrated in Figure 9. ASN.1 types shall be as specified in Annex A.
serviceList
No. of
nonipService ITS-AID serviceData serverPort sessionChannel
elements
multiple instances of nonipService
Figure 9 — serviceList
The elements serviceData, serverPort, and sessionChannel shall always be present, but may not be used
always as explained below.
Elements of nonipservice are:
— ITS-AID: ITS application object identifier of ASN.1 type ITSaid specified in [4];
— serviceData: data of ASN.1 type ServiceData related to ITS-AID shall be present if required by the
ITS application object specification. If this element is not used, the length indicator shall be set to zero;
— serverPort: information of ASN.1 type PortNumber on the receive port number of the service
provider shall be present when a reply is expected. If this element is not used, the value PORT_UNK
(unknown, don’t care) identified in [5] shall be used;
— sessionChannel: pointer to a communication channel contained in channelList shall be present when
the SOP shall use a communication channel different to the one used for the SIP. If this element is not
used, the value zero shall be used.
The elements in channelList shall be of ASN.1 type SessionChannel specified in Annex A.
NOTE There may be a limitation on the size of a SAM depending on the properties of the access technology
used to transmit it.
7.2.3 Service context message
The elements of the service context message (CTX) PDU identified by FMT-ID = “ctx” (1) are illustrated
in Figure 10. The CTX PDU shall be of ASN.1 type CTX specified in Annex A. Details of the element
ipContextList will be provided in a future version of this part of ISO 24102.
Context Message (CTX)
Header Body
FMT-ID clientID
Version servContextList ipContextList
(ctx) (StationID)
Figure 10 — Service context message PDU
Elements of CTX are:
— Header
— FMT-ID = “ctx” (1), identifying CTX;
— version number of this part of ISO 24102-5;
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ISO 24102-5:2013(E)
— clientID of the service client ITS station, which shall be of ASN.1 type StationID specified
in Annex A.
— Body
— servContextList: information on service contexts of ASN.1 type ServContextList available
at the service client ITS station. May be present as a reply to a service offered in serviceList;
— ipContextList: information on service contexts of ASN.1 type IpContextList available at the
service client ITS station, which will require IPv6 networking in the SOP. May be present as a
reply to a service offered in ipServList.
These elements in the Body consist each of a length field followed by the data as specified in Annex A. At
least either servContextList or ipContextList shall have a data length different to zero.
An entry in the servContextList shall be of ASN.1 type noIpContexts specified in Annex A and
illustrated in Figure 11.
servContextList
No. of
nonipContext ITS-AID contextData clientPort
elements
multiple instances of nonipContext
Figure 11 — servContextList
Elements of servContextList are:
— ITS-AID: ITS application object identifier of ASN.1 type ITSaid specified in [4];
— contextData: context data of ASN.1 type ContextData specified in Annex A;
— clientPort: information of ASN.1 type PortNum
...
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