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SAE J2735-Draft-Rev18 [issued: 06-26-07]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
3.12 control channel (CCH): The radio channel of those defined in IEEE 802.11p used for exchange of
management data and WAVE Short Messages
3.13 Controller Assembly: A complete electrical device mounted in a cabinet for controlling the operation
of a highway traffic signal.
3.14 Controller Unit: That part of a controller assembly that is devoted to the selection and timing of the
display of signal indications
3.15 Critical lane volume: Definition to be refined by committee.
3.16 cycle: Definition to be refined by committee.
3.17 Cycle Length: The time required for one complete sequence of signal indications.
3.18 Dark Mode: The lack of all signal indications at a signalized location. (The dark mode is most
commonly associated with power failures, ramp meters, beacons, and some movable bridge signals.)
3.19 data: Representations of static or dynamic entities in a formalized manner suitable for
communication, interpretation, or processing by humans or by machines.
3.20 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.
3.21 data consumer: Any entity in the ITS environment which consumes data from others.
3.22 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.
3.23 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.
3.24 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).
3.25 data plane: The communication protocols defined to carry application and management data across
the communications medium.