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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.
Used By: This entry is used directly by one other data structure in this standard, a DF called
DF_SpaceVector <ASN> <XML>. In addition, this item may be used by data structures in other ITS
standards.
Remarks: This element was originally defined in J2313. From Section 8.15 "Location-Tech."
7.5 Data Element: DE_Priority
Use: A priority for the alert message, giving urgency of this message. A relative degree of merit compared
with other similar messages for this type (not other message being sent by the device, nor a priority of
display urgency at the receiver).
At this time, the lower five bits are reserved and shall be set to zero. This effectively reduces the number of
priority levels to eight. The value of all zeros shall be used for "routine" messages such as roadside signage
where not displaying the message to the drive is of only modest impact. The value 111xxxxx shall be the
highest level of priority and shall be consider the most important level. When choices of display order or
transmission order are considered, messages with this level of priority shall be given precedence. The
remaining 6 levels shall be used as determined by local conventions.
ASN.1 Representation:
Priority ::= INTEGER (0..255)
-- Follow definition notes on setting these bits
XML Representation:
<xs:simpleType name="Priority" >
<xs:annotation>
<xs:documentation>
Follow definition notes on setting these bits
</xs:documentation>
</xs:annotation>
<xs:restriction base="xs:unsignedByte"/>
</xs:simpleType>
Used By: This entry is used directly by one other data structure in this standard, a MSG called
MSG_RoadSideAlert <ASN> <XML>. 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.
7.6 Data Element: DE_URL_Base
Use: A valid internet style URI / URL in the form of a text string which will form the base of a compound
string which, when combined with the URL-Short data element, will link to the designated resource. The
string is to be interpreted as case-insensitive . Lower case is recommended. The protocol to be used (such
as http) should be given in the string, The very last letter of the string may be used to differentiate multiple
URL-Base values in a single system. This allows for a total of up to 26+10= 36 such base addresses to
exist. This last letter is then used to differentiate which base a given short value is to be used with (a
matching first letter in the URL-Short value is also used). These letters are stripped from both the base and
short data elements before combining to create the final URL/URI value.
ASN.1 Representation:
URL-Base ::= IA5String (SIZE(1..45))
XML Representation:
<xs:restriction base="xs:anyURI">
<xs:minLength value="1"/>
<xs:maxLength value="255"/>
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