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SAE J2735-Draft-Rev29 [issued: 12-11-08]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
approach consists of one or more motor vehicle lanes of travel as well as possible pedestrian lanes, parking
lanes, barriers, and other types of lane objects some of which cross the path of the motor vehicle travel.
3.7 byte type encoding: A type of information encoding where units of information are handled in modular
increments of 8 bits.
3.8 computed lane: A computed lane is a lane drivable by motorized vehicle traffic which shares its path
definition with another nearby lane at the same intersection. It is one of several types of basic lanes defined
in the message set. The computed lane allows saving of message bytes used to express the geometric path
of multiple lanes approaching an intersection from the same direction.
3.9 conflict monitor: A device used to detect and respond to improper or conflicting signal indications and
improper operating voltages in a traffic controller assembly.
3.10 control channel (CCH): The radio channel of those defined in IEEE 802.11p used for exchange of
management data and WAVE Short Messages.
3.11 Controller Assembly: A complete electrical device mounted in a cabinet for controlling the operation
of a highway traffic signal.
3.12 Controller Unit: That part of a controller assembly that is devoted to the selection and timing of the
display of signal indications.
3.13 cycle: One complete sequence of signal indications.
3.14 cycle length: The duration of one complete sequence of signal indications. The cycle length is not
generally fixed at actuated controllers.
3.15 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.) Note
that when the SPAT message is used to convey the status of a non-signalized 4-way stop type of
intersection, if an approach is modeled as being in the dark mode, it would indicate that the signage is
missing (normally a flashing red stop would be indicated).
3.16 data: Representations of static or dynamic entities in a formalized manner suitable for
communication, interpretation, or processing by humans or by machines.
3.17 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.
3.18 data consumer: Any entity in the ITS environment which consumes data from others.
3.19 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.