ISO 21212:2008

INTERNATIONAL ISO
STANDARD 21212
First edition
2008-11-01
Intelligent transport systems —
Communications access for land mobiles
(CALM) — 2G Cellular systems
Systèmes de transport intelligents — Accès de communication pour
services mobiles terrestres (CALM) — Systèmes cellulaires 2G

Reference number
©
ISO 2008
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ii © ISO 2008 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Conformance. 1
3 Normative references . 1
4 Terms and definitions. 2
5 Abbreviated terms . 2
6 Requirements . 3
6.1 Adoption of other standards and internationally adopted practices . 3
6.2 Non packet-switching cellular networks . 3
6.3 CALM architecture. 3
6.4 CALM networking protocols. 3
6.5 CALM service access points . 3
6.6 CALM interface manager . 3
6.7 CALM using public wireless networks . 4
6.8 Establishment of a medium specific session . 4
6.9 Interface medium management. 4
7 Medium access control (MAC) . 4
7.1 CALM 2G/2.5G cellular communications MMAE service primitives. 4
7.2 CALM 2G/2.5G cellular communications MMAE functionality. 6
8 Test and conformance requirements. 6
9 Marking, labelling and packaging . 7
10 Declaration of patents and intellectual property. 7

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 21212 was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.

iv © ISO 2008 – All rights reserved

Introduction
This International Standard is part of a family of International Standards for CALM (“Communications Access
for Land Mobiles”) which specify a common architecture, network protocols and communications interface
definitions for wireless communications using different bearer technologies, e.g. second and third generation
cellular, 5 GHz microwave, 60 GHz millimetre-wave, mobile wireless broadband, and Infra-red
communications. Other air interfaces may be added at a later date. These wireless communications interfaces
are designed to provide parameters and protocols for broadcast, point-point, vehicle-vehicle, and vehicle-point
communications in the ITS Sector.
This International Standard determines the air interface parameters for CALM communications via 2G/2.5G
cellular networks.
CALM standards are explicitly designed to enable quasi-continuous communications as well as
communications of protracted duration between vehicles and service providers, and between vehicles.
The fundamental advantage of the CALM concept over traditional systems is the ability to support media
independent handover (MIH), also referred to as heterogeneous handover, between the various media
supported by CALM (e.g., cellular, microwave, mobile wireless broadband, infra-red, DSRC). Selection
policies are supported that include user preferences and media capabilities in making decisions as to which
media to use for a particular session, and when to handover between media or between service providers on
the same medium. These handover mechanisms are defined within the CALM architecture International
Standard (ISO 21217), the CALM networking protocols International Standard (ISO 21210), the CALM
medium service access points International Standard (ISO 21218) and the CALM management International
Standard (ISO 24102). Handovers between access points using the same technology and service provider
use mechanisms that are defined within the particular medium specific CALM Standard.
ITS applications include the update of roadside telemetry and messaging, internet, image and video transfer,
infotainment, multimedia multicast, traffic management, monitoring and enforcement in mobile situations,
route guidance, car-to-car and point-to-multipoint safety messaging, maintenance management, and “yellow
page” services among others.
This International Standard provides definitions and procedures for the establishment and maintenance of an
ITS communications session within a CALM system environment using 2G/2.5G cellular communications.

INTERNATIONAL STANDARD ISO 21212:2008(E)

Intelligent transport systems — Communications access for
land mobiles (CALM) — 2G Cellular systems
1 Scope
This International Standard determines the air interface for second generation (2G) cellular networks and 2G
systems (e.g. using WAP and I-Mode type protocols) to be compliant to CALM, i.e., requirements that must be
met before a 2G system can be incorporated into a CALM system. In particular, this International Standard
specifies protocols and parameters that 2G systems shall include to support prolonged, long-range, high data
rate wireless communication links in ITS environments where heterogeneous handovers or media
independent handovers (MIH) are either necessary to maintain the link, or desirable as determined by media
selection policies.
This International Standard provides protocols and parameters for long range, medium speed wireless
communications in the ITS sector using second generation cellular communications.
Wherever practicable, this International Standard has been developed by reference to suitable extant
standards, adopted by selection. Required regional variations are provided.
Specifically, for this International Standard, extant 2G systems, as defined by various international and
national standards, are adopted by reference.
Application-specific upper layers are not included in this International Standard, but will be driven by
application standards (which may not be technology specific).
2 Conformance
In order to claim conformance with this International Standard, cellular communication shall be established in
full compliance with local telecommunications procedures and protocols for the appropriate 2G/2.5G
Standards, and shall comply with the requirements of ISO 21210, ISO 21217, ISO 21218 and ISO 24102 (see
Clause 3).
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 21210, Intelligent transport systems — Communications access for land mobiles (CALM) — Networking
Protocols
ISO 21217, Intelligent transport systems — Communications access for land mobiles (CALM) — Architecture
ISO 21218, Intelligent transport systems — Communications access for land mobiles (CALM) — Medium
service access points
ISO 24102, CALM Management
...