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SAE J2735-Draft-Rev29 [issued: 12-11-08]
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223 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
9.2 Message: MSG_MapData (GID Layer)
Use: The MapData message is used as wrapper object to relates all the types of maps defined in the
standard. This includes such items as complex intersection descriptions (used with the SPAT message),
high speed curve outlines (used in curve safety alerts), and segment of roadway (used in platoon
applications). The contents of this message are at time informally referred to as the GID layer.
ASN.1 Representation:
MapData ::= SEQUENCE {
msgID DSRCmsgID,
msgCnt MsgCount,
-- updated when message content changes
name DescriptiveName OPTIONAL,
layerType LayerType OPTIONAL,
layerID LayerID OPTIONAL,
intersections SEQUENCE (SIZE(1..32)) OF
Intersection OPTIONAL,
-- other objects may be added at this layer, tbd,
-- this might become a nested CHOICE statement
-- roadSegments SEQUENCE (SIZE(1..32)) OF
-- RoadSegments OPTIONAL,
-- curveSegments SEQUENCE (SIZE(1..32)) OF
-- curveSegments OPTIONAL,
-- wanted: some type of data frame describing how
-- the data was determined/processed to go here
dataParameters DataParameters OPTIONAL,
crc MsgCRC,
... -- # LOCAL_CONTENT
}
XML Representation:
<xs:complexType name="MapData" >
<xs:sequence>
<xs:element name="msgID" type="DSRCmsgID" />
<xs:element name="msgCnt" type="MsgCount" />
<!-- updated when message content changes -->
<xs:element name="name" type="DescriptiveName" minOccurs="0"/>
<xs:element name="layerType" type="LayerType" minOccurs="0"/>
<xs:element name="layerID" type="LayerID" minOccurs="0"/>
<xs:element name="intersections" minOccurs="0">
<xs:complexType>
<xs:sequence minOccurs="1" maxOccurs="32">
<xs:element name="intersection" type="Intersection" />
</xs:sequence>
</xs:complexType>
</xs:element>
<!-- other objects may be added at this layer, tbd,
this might become a nested CHOICE statement
roadSegments SEQUENCE (SIZE (1..32) ) OF
RoadSegments OPTIONAL ,
curveSegments SEQUENCE (SIZE (1..32) ) OF
curveSegments OPTIONAL ,
wanted: some type of data frame describing how
the data was determined/processed to go here -->
<xs:element name="dataParameters" type="DataParameters" minOccurs="0"/>
<xs:element name="crc" type="MsgCRC" />
<xs:element name="localMapData" type="local:MapData" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
Remarks: Issues: Not clear how multiple intersections would really be used in this concept. It may be
that complex intersections must be broken down this way. It may be that sending sets of locally nearby
intersections (although each is independent may be the answer).