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SAE J2735-Draft-Rev28 [issued: 11-10-08]
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39 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
1~2 bytes in length -->
<xs:element name="crc" type="MsgCRC" />
</xs:sequence>
</xs:complexType>
Used By: This entry is used directly by one other data structure in this standard, a MSG called
MSG_EmergencyVehicleAlert <ASN> <XML>. In addition, this item may be used by data structures
in other ITS standards.
Remarks: This message is also used a building blocm for other DSRC messages. When used in other
public safety messages, additional elements may be appended to form new message types.
5.12 Message: MSG_RTCM_Corrections
Use: The RTCM_Corrections message is used to encapsulate RCTM differential corrections for GPS and
other radio navigation signals as defined by the RTCM (Radio Technical Commission For Maritime
Services) special committee number 104 in its various standards. Here, in the work of DSRC, these
messages are "wrapped" for transport on the DSRC media, and then can be re-constructed back into the
final expected formats defined by the RCTM standard and used directly by various positioning systems to
increase the absolute and relative accuracy estimates produced.
ASN.1 Representation:
RTCM-Corrections ::= SEQUENCE {
msgID DSRCmsgID,
msgCnt MsgCount,
-- the specific edition of the standard
-- that is being sent
-- the message and sub-message type, as
-- defined in the RTCM revision being used
status GPSstatus,
...
}
XML Representation:
<xs:element name="rTCM-Corrections" type="RTCM-Corrections"/>
<xs:complexType name="RTCM-Corrections" >
<xs:sequence>
<xs:element name="msgID" type="DSRCmsgID" />
<xs:element name="msgCnt" type="MsgCount" />
<!-- the specific edition of the standard
that is being sent -->
<xs:element name="msg" type="RTCM-MsgType" />
<!-- the message and sub-message type, as
defined in the RTCM revision being used
NOTE as the message type is also in the payload,
we may want to remove it from here, not sure right now. DCK -->
<xs:element name="wdCount" >
<xs:simpleType>
<xs:restriction base="xs:unsignedShort">
<xs:maxInclusive value="1023"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
<!-- a count of bytes to follow -->
</xs:sequence>
</xs:complexType>
In addition, this item may be used by data structures in other ITS standards.
Remarks: Observe that the transport layer details (preamble, CRC, etc.) as outlined in RTCM standard
10403.1 version 3.0 clause four are not sent in this message. In a similar fashion, the same framing