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SAE J2735-Draft-Rev18 [issued: 06-26-07]
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147 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
In addition, this item may be used by data structures in other ITS standards.
Remarks: Note that a well chosen roadway with a set of priority schemes chosen to be very well managed
can be thrown into chaos when an incident event occurs in it and when emergency response equipment
enters the transmission zone during the response to the event. Local agreements on practices, including
road side unit (RSU) placement, will be needed to insure correct operation.
8.7 Data Element: DE_Speed [ATIS]
Use: Need to define.
ASN.1 Representation:
Speed ::= INTEGER (0..100) -- edit to proper ranges
XML Representation:
<xs:simpleType name="Speed" >
<xs:annotation>
<xs:documentation>
edit to proper ranges
</xs:documentation>
</xs:annotation>
<xs:restriction base="xs:unsignedByte">
<xs:maxInclusive value="100"/>
</xs:restriction>
</xs:simpleType>
Used by: This entry is directly used by the following 5 other data structures in this standard (record type,
descriptive name, ASN.1, and XML name (if present) of each):
DF
<XML>, and
DF
<XML>, and
DF
<XML>, and
MSG
<XML>, and
DF
In addition, this item may be used by data structures in other ITS standards.
8.8 Message: MSG_RoadSideAlert [ATIS]
Use: This message is used to send alerts for nearby hazards to travelers. Unlike most messages which use
the LRMS profiles to describe the areas affected, this message likely applies to the receiver by the very fact
that it is received. In other words, it does not use LRMS. Typically transmitted over the Dedicated Short
Range Communications (DSRC) media, this message provides simple alerts to travelers (both in vehicle
and with portable devices). Typical example messages would be "bridge icing ahead" or "train coming" or
"ambulances operating in the area." The full range of ITIS phrases are supported here, but those dealing
with mobile hazards, construction zones, and roadside events are the ones most frequently expected to be
found in use.
This message is for the alerting of roadway hazards; not for vehicle cooperative communications, mayday,
or other safety applications (see SAE J2735 for these). It is generally presumed that each receiving device
is aware of its own position and heading, but this is not a requirement to receive and understand these
messages. Nor is having a local base map.
The space vector section of the message gives a simple vector for where the hazard is located (fixed or
moving) and can be used to filter some messages as being not applicable. Consider a "train approaching"
message which indicates the train is in fact traveling away from the receiver. The basic messages types
themselves are represented in the standard ITIS codes send only in their integer representation formats.