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SAE J2735-Draft-Rev15 [issued: 01-30-07]
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27 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
<xs:element name="blockCount" >
<xs:simpleType>
<xs:restriction base="xs:unsignedShort"/>
</xs:simpleType>
</xs:element>
<!-- the number of blocks in total -->
<xs:element name="wordCount" >
<xs:simpleType>
<xs:restriction base="xs:unsignedShort"/>
</xs:simpleType>
</xs:element>
<!-- the number of bytes in this payload -->
<xs:element name="payLoad" type="PayloadData" />
<!-- the payload data to be transferred -->
<xs:element name="crc" >
<xs:simpleType>
<xs:restriction base="xs:unsignedShort"/>
</xs:simpleType>
</xs:element>
<!-- a CRC, if not provided by the framing -->
</xs:sequence>
</xs:complexType>
Remarks: This message allows for transfer of up to 4,295 Megs of data to be sent per session per application
using a simplistic method without error recovery, but with basic error detection. It is intended to be a utility method
to be used in developing DSRC applications, and not to be used or depended upon in real time operational
systems because its excessive use by any party would easily disturb time critical systems by excessive
bandwidth consumption.
5.6 Message: MSG_MapFragment
Use: The Map Fragment message is used to send small self contained maps of intersections and roadway
geometry to mobile users. The most common use is in connection with the local roadway geometry needed to
support applications relating to intersection intrusion safety
ASN.1 Representation:
MapFragment ::= SEQUENCE {
id NationalIntersectionID,
--- unique ID of some sort
cnt INTEGER (0..256),
-- count of object defintions that follow
objs SEQUENCE (SIZE(0..256)) OF CHOICE {
anchor Anchor,
zoom Zoom,
point Point,
line Line,
shape Shape,
approach Approach,
phase Phase,
overlap Overlap,
etc Etc
},
-- a collection of basic map objects,
-- the precise nature TBD
-- and nesting vs flat or linked TBD
...
}
XML Representation:
<xs:complexType name="MapFragment" >
<xs:sequence>
<xs:element name="id" type="NationalIntersectionID" />
<!-- - unique ID of some sort -->