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SAE J2735-Draft-Rev26 [issued: 09-18-08]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
3.36 functional-area data dictionary (FADD): A data dictionary that is intended to standardize data
element syntax, and semantics, within and among application areas within the same functional area. This
DSRC standard is a FADD.
3.37 GID layer: Definition to be refined by committee.
3.38 ingress: In the context of this standard an egress is a flow of vehicular or other types of traffic
approaching an intersection on one or more of the defined lanes of travel.
3.39 initialization: One of three modes, or states, of operation known as Registration, Initialization, and
Operations which DSRC systems operate in. The Initialization mode is used to establish a direct
connection (link) between two DSRC devices. It is comparable to, but not equivalent to, an IEEE 802.11
association.
3.40 intelligent transportation systems (ITS): Systems that apply modern technology to transportation
problems. Another appropriate meaning of the ITS acronym is integrated transportation systems, which
stressed that ITS systems will often integrate components and users from many domains, both public and
private.
3.41 interoperability: The ability to share information between heterogeneous applications and systems.
3.42 intersection: In the context of this standard an intersection is a nexus where two or more approaches
meet and vehicles and other type users may travel between the connecting links. Typically this is a
signalized intersection when considered by this standard, and as such the modes of allowed travel are
reflected in the signal phases, the geometry of the intersection itself, and the local regulatory environment.
The messages of this standard convey some of this information to the traveling public. Specifically, the
MAP message conveys the relevant the road geometry, while the SPAT message conveys the current signal
indication to allow and control movement in the intersection.
3.43 intersection control beacon: A beacon used only at an intersection to control two or more directions
of travel.
3.44 interval: The part of a signal cycle during which signal indications are stable and do not change. In
the SPAT message the current timing value for the remaining interval time estimate as well as the
anticipated interval for yellow change interval is provided for each lane. Because signal interval times
commonly change based on triggering events in many types of signaling systems, the value provided in the
SPAT message may represent a minimal value that is extended and updated as the message is re-issued
each time.
3.45 interval sequence: 3.48 interval sequence: The order of appearance of signal indications during
successive intervals of a signal cycle.
3.46 ITIS: International Traveler Information Systems, the term commonly associated with the standard for
incident phrases developed by the SAE ATIS Committee in conjunction with ITE TMDD and other
standards. This work contains a wide variety of standard phrases to describe incidents and is expected to be
used throughout the ITS industry. The codes found there can be used for sorting and classifying types of
incident events, as well as creating uniform human readable phrases. In the capacity of classifying incident
types, ITIS phrases are used in many areas. ITIS phrases can also be freely mixed with text and used to
describe many incidents.
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