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SAE J2735-Draft-Rev15 [issued: 01-30-07]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
3. TERMS AND DEFINITIONS
For the purposes of this standard, the following definitions, abbreviations and acronyms apply.
3.1 Definitions
For the purposes of this standard, the following definitions shall apply.
3.1 airlink: A radio frequency communication interface, such as that defined by WAVE.
3.2 application class identifier (ACID): A code that identifies a class of application, as defined by the IEEE.
3.3 application context mark (ACM): A code identifying a specific instance of an application (as defined in IEEE
documents).
3.4 application-specific data dictionary: A data dictionary specific to a particular implementation of an ITS
application. Local deployments which use DSRC (or other message sets) may often select a subset of the defined
messages meeting their specific needs and create an application-specific data dictionary for that deployment.
3.5 byte type encoding: A type of information encoding where units of information are handled in modular
increments of 8 bits.
3.6 control channel (CCH): The radio channel of those defined in IEEE 802.11p used for exchange of
management data and WAVE Short Messages
3.7 data: Representations of static or dynamic entities in a formalized manner suitable for communication,
interpretation, or processing by humans or by machines.
3.8 data concept: Any of a group of data dictionary structures defined in this standard (e.g., data element, data
element concept, entity type, property, value domain, data frame, or message) referring to abstractions or things in
the natural world that can be identified with explicit boundaries and meaning and whose properties and behavior all
follow the same rules.
3.9 data consumer: Any entity in the ITS environment which consumes data from others.
3.10 data dictionary: An information technology for documenting, storing and retrieving the syntactical form (i.e.,
representational form) and some usage semantics of data elements and other data concepts. The major message
sets of ITS, of which DSRC is but one, are kept and represented in a data dictionary.
3.11 data element: A syntactically formal representation of some single unit of information of interest (such as a
fact, proposition, observation, etc.) with a singular instance value at any point in time, about some entity of interest
(e.g., a person, place, process, property, object, concept, association, state, event). A data element is
considered indivisible.
3.12 data frame: (formerly: Data Structure, which appears in the early ITS efforts, is now more commonly called a
Data Frame. The definition and meaning, which follows, remains the same.): Any construct used to represent the
contents of a Data Dictionary. From a computer science perspective, data frames are viewed as logical groupings
of other data frames and of data elements to describe "structures" or parts of messages used in this and other
standards. A data frame is a collection of one or more other data concepts in a known ordering. These data
concepts may be simple (data elements) or complex (data frames).
3.13 data plane: The communication protocols defined to carry application and management data across the
communications medium.
3.14 data registry: An advanced data dictionary that contains not only data about data elements in terms of their
names, representational forms and usage in applications, but also substantial data about the semantics or
meaning associated with the data elements as concepts that describe or provide information about real or abstract