DENM-PDU-Descriptions {
 itu-t (0) identified-organization (4) etsi (0) itsDomain (5) wg1 (1) ts (102637) denm (3) version2 (2) 
}

DEFINITIONS AUTOMATIC TAGS ::= 

BEGIN

IMPORTS 
    ItsPduHeader, Latitude, Longitude, Elevation, Speed, VehicleCommonParameters, ProfileParameters, StationID, TimeStamp, ReferencePosition 
FROM CAM-PDU-Descriptions { itu-t (0) identified-organization (4) etsi (0) itsDomain (5) wg1 (1) ts (102637) cam (2) version1 (1) };


DenmPdu ::= SEQUENCE {
	header	ItsPduHeader,	
	denm	DecentralizedEnvironmentalNotificationMessage

}

DecentralizedEnvironmentalNotificationMessage ::= SEQUENCE {
	
	management	DecentralizedSituationManagement,	--  container with DEN management and version control
	situation	DecentralizedSituation,  			-- container with event description, incl. type, severity
	location	DecentralizedSituationLocation,		-- container with event location, location referencing with more detailed location description and the relevance area
	
	...
 }

DecentralizedSituationManagement::= SEQUENCE {
	-- unique identifier about an event from one originator ITS station, combination of node ID and a sequence number
	actionID	ActionID,	-- 6 byte
	
	-- version of the DENM indicating updates from the same originator ITS station; value of 255 is used for the  cancellation message sent from the originator ITS station
	
	dataVersion	DataVersion,  	-- 1 byte
	-- time when the DENM is deleted from the DEN management and the information related to the event is set as invalid.. If it is not provided, it indicates that the expiry time is unkown by the originator ITS station	
	expiryTime	TimeStamp  	OPTIONAL, 	-- 6 byte
	frequency	INTEGER (0..255)	OPTIONAL, 	--units of 0.1 Hz
	-- probability of the detected event to  be true, varies  from 0 to 100, with maximum value as full reliability
	reliability	INTEGER(0..100), 	-- 7 bits
	-- negates the existence of an event at the event position by a third part ITS station that have received DENMs previously.		 
	isNegation	BOOLEAN    		-- 1 bit	
}

-- event description derived from [3]
DecentralizedSituation::= SEQUENCE {
	-- traffic status near the event position, defined based on [3], TPEG table tec001 
	trafficFlowEffect 	TrafficFlowEffect	OPTIONAL,	 -- 1 byte. 
	-- event direct cause and sub cause description as defined in tab6.1 and in [3]
	situation	Situation,
	-- linked cause if information is available.
	linkedCause	Situation		OPTIONAL,	-- 2 Byte, 
	-- severity value of the event, defined in [3], TPEG table tec003			
	severity	Severity,	-- 1 byte
	-- characteristics of the event 
	eventCharact	SEQUENCE -- EventCharact 1 byte 
	{
		-- event mobility description, set to TRUE if the event is in mobility 
		eventmobility	BOOLEAN,
		-- whether the event is caused by the originator ITS station
		causeType   ENUMERATED { itsStation, geographicalRegion },
		-- whether the event is physicalling relevant to the  receiving ITS station.
		relevance ENUMERATED {physicallyRelevant, difficultDrivingConditions },
		-- whether the event is time critical road safety event, set to TRUE if it is the case.
		timeCriticality	BOOLEAN,
		-- more characteristics may be added in future.
		...
	} OPTIONAL,
		
	vehicleCommonParameters	VehicleCommonParameters OPTIONAL,
	profile ProfileParameters    OPTIONAL
}

DecentralizedSituationLocation::= SEQUENCE {
	-- description of the event position
	eventPosition	CHOICE	{
		-- the geographical position of the reference position 
		eventPositionCurrentDefinition	EventPosition,
		...
	},
	-- description of  the relevance area for the  DENM dissemination
	-- location referencing of the event position
	locationRef	CHOICE {
		-- consequence position of the trace location referencing mechanism
		trace	TraceLocData,
		-- more location referencing mechanism to be added
		...
	},
	...
}

EventPosition ::= SEQUENCE {
		refPosition	ReferencePosition,
		eventSpeed	Speed OPTIONAL	-- event speed, either equal to or different from the vehicle speed
}

		
ActionID ::= SEQUENCE {
	stationID 	StationID,	-- a 4 byte value
	sequenceNo 	SequenceNo	-- a 2 byte value
}

SequenceNo ::=	INTEGER (0..65535)		-- increased by 1 each time a new event is detected by the same ITS  station.

DataVersion ::= INTEGER {firstVersion(0),secondVersion(1),cancellation(255) } (0..255)

TrafficFlowEffect ::= 	INTEGER (0..7)

Situation ::= SEQUENCE {
	cause 		CauseCode, 	-- 1 byte
	subCause	SubCauseCode	-- 1 byte
}

-- 1 to 100 indicates causecode defined within [3]
-- 101 – 255 indicates causecode without being defined by [3]
CauseCode ::= INTEGER {reserved(0),dangerousDriving(101),intersectionViolation(102),vehicleProblem(103),intersectionCollision(104),hazardousLocation(105) } (0..255)

SubCauseCode ::= INTEGER {unknown(0)} (0..255)

Severity ::= ENUMERATED 		-- 1 byte
{
	informative		(1), 
	-- Text example: <Attention, there is a dangerous obstruction due to fog>
	obstacles		(2),	--danger level 1
	-- Text example: <Attention, there a danger due to fog>
	danger	(3),			--danger level 2: 
	-- Text example: <Attention, highest danger due to fog>
	highestDanger	(4)		--danger level 3: 
}

TraceLocData ::=	SEQUENCE {
	--3 bits, identifier of the trace
	traceID	INTEGER(0 .. 7),	
	--5 bits, number of waypoint positions included in the trace
	waypoints	SEQUENCE (SIZE(0..31)) OF	Waypoint
}

Waypoint  ::=		SEQUENCE{
	--  waypoint positions included in the trace.	
	ptLat 	Latitude,							--a 4 bytes value 
	ptLong 	Longitude,						--a 4 bytes value
	ptAlt 	Elevation,
	...
}

END