Why Do We Need to Work Together
• EU-JPN-US V2V safety & mobility application already have much similarity on data needs, e.g.– High-accuracy vehicle dynamic data at high and/or flexible
transmission interval– Event-triggered additional data transmission needs– Accurate lane-level traffic signal phase, timing related info needs
• Data similarity can lower global development cost on similar applications– Common/Similar message set, data elements and quality of
data facilitate V2X implementation from one region to be “reused” by other regions with min. duplicated work
– Does not have to be identical however the core elements should be available across the region with reasonably similar/same quality assurance
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US-EU V2V/V2I Standards Compare/Contrast
IEEE 1609.3 1609.4Network Layer
SAE J2735 J2945Message set &
data performance requirementsApplication Layer
IEEE
1609.
2
Secu
rity
fu
nct
ion
s
IEEE 802.11p PHY Layer
• Similar architectures• Security protocol and physical layer standards are near identical• Message set data elements are similar• However application layer, channel congestion control and performance requirements differs-It is OK to remain different
3
SAE J2735 Defined Messages
ID Messages Typical Use Status
0 Reserved N/A
1 MSG_A_la_Carte V2X
2 MSG_BasicSafetyMessage (BSM) V2V Used by USDOT program & other ITS industry research
3 MSG_CommonSafetyRequest V2?
4 MSG_EmergencyVehicleAlert
5 MSG_IntersectionCollisionAvoidance V2X
6 MSG_Map I2V Based on USDOT previous project. Used by various demo/research program
7 MSG_NMEA_Corrections I2V
8 MSG_ProbeDataManagement I2V Used by VII Proof of Concept (PoC) project
9 MSG_ProbeVehicleData V2I Used by VII PoC project
10 MSG_RoadSideAlert
11 MSG_RTCM_Corrections I2V Based on USDOT previous project. Used by various demo/research program
12 MSG_SignalPhaseAndTiming I2V Based on USDOT previous project. Used by various demo/research program
13 MSG_SignalRequestMessage V2I
14 MSG_SignalStatusMessage I2V
15 MSG_TravelerInformation Message I2V Used by VII PoC & will be used in Model Deployment (Curve Speed Warning)
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V2V Messages: Where We Were 2.5 Years Ago
Part II Optional
Path History
Path PredictionRTCM Package
Event Flags
Other vehicle data…
U.S. V2V Safety Msg
Message CountVehicle Temp ID
Time Stamp
LatitudeLongitudeElevation
TransmissionAndSpeedHeading
Acceleration (4way)
Brake Status
Steering Wheel Angle
PositionalAccuracy
Vehicle Size
Message Type
… …
Illustration of BSM Part I & Part II Transmission interval
… …
Illustration of CAMP Understanding of ETSI CAM Transmission interval
• CAM & BSM has significant difference in use cases and application design
• As result, major difference in data format & definition
• Transmission interval also varies very much
• Rationales of the difference unclear
• Requires face-to-face technical detailed walk through
Data in diifference
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2011 2012 2013
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
US-EU V2V Message Collaboration Progress
ETSI WG1 workshop
ETSI WG1 Workshop
ETSI WG1 Workshop
Reached Step 1 data elements harmonization •Align remaining
elements•Continue performance requirements discussion
• Achieved same/similar data element level definition & availability for most of the critical data elements in V2V messages ETSI’s CAM and US SAE’s Basic Safety Message (BSM)
• Borrowed from EU’s field experience, SAE is considering encoding format change to match EU’s more efficient way
• Started and continuing discussion on definition of performance requirement– Such as latency definition, data age definition, DSRC propagation range definition and testing
method
• Step 2: Harmonizedmore data elements;• Identified high-level difference among ETSI-SAE-ISO
•Review latest revision candidate list from SAE•Confirm latest CAM and data dictionary changes
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CAM-BSM Compare & Contrast-Overview 2013
CAM
Message ID
Station ID
GenerationDelta Time
Station Type
Latitude
Longitude
Elevation
PositionConfidence
Speed
DriveDirection
Heading
LongitudinalAcceleration
AccelerationControl
Curvature
VehicleWidth
VehicleLength
ExteriorLights
PathHistory
Optional elements
LaneCount …
BSM
Message Type
Message Count
Vehicle Temp ID
Time
Latitude
Longitude
Elevation
Positional accuracy
Transmission & speed
Heading
Steering wheel angle
Acceleration 4 way
Brake status
Vehicle size
Event flags (optional)
Path history
Path prediction
RTCM package (optional)
Other vehicle
data/Containers(optional)
…
• Most critical vehicle dynamic data are “matched”same or similar definition
• EU’s CAM continue to progress with accommodating various vehicle type needs vs US BSM so far focuses on light vehicle-something US can learn from EU once heavy vehicle related DSRC activity progresses further
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2012 2013 2014
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
US-EU V2I Message Collaboration Progress• Strong support from EU and Japan team as part of the ISO/CEN/SAE collaboration
• Expert team formed with highly productive and intensive technical discussion
• Agreement reached to adopt SAE J2735 SPaT Map format with regional specifics and regional control on revision
• By far one of the greatest success on collaborated global standards development, thanks to the spat/map expert team’s persistence and effort
SPaT/Map workshop
• Explained J2735 SPaT Map msg and data structure•Detailed review of SPaT/GID message & data contents
SPaT/Map Delft mtg
• Formed SPaT/Map expert team from EU/US/JPN•Collaborate with CEN/ISO/SAE
Regular mtgs & draft iterations following during ISO/CEN schedule
• SAE Balloting started !
• Expected publication date
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Joint owner ship, close work relation & regional flexibility are the key to collaboration success
• EU/JPN/US common message format (90% or more are common) with small regional specific sections under regional expert’s management
• US is learning from EU and Japan expert on some of the core technical directions– Discussing adoption of EU’s more efficient encoding rule
– More efficient way of describing allowed maneuvers
Signal Phase & Timing & Map Msg New Common Format
Map
Msg ID
SubID (optional)
Revision
LayerType(optional)
LayerID (optional)
IntersectionCount (optional
Seq. of Intersections
RoadSegments (optional)
DataParameters (optional)
RestrictionList (optional)
Regional Map(optional)
…
SPaT
Msg ID
SubID (optional)
Name (optional)
IntersectionCount
(optional)
Seq. of Intersections
Regional SPaT (optional)
EU specific Elements/Frames
Altitude Value, Confidence
EmissionType Type A, B, C,…
PrioritizationResp. StationID, PrioState, SignalGroupID
…
Japan specific Elements/Frames
Angle Value, Confidence
Abs. Lat/Lon/Elev. Full absolute value for nodes
Counter
MovementEvent Start/end min & Max time, likely time, conf, …
…
9
SAE DSRC Message Set Development Planned Timing(Tentative)
• Revision to the SAE J2735 Standard– Potential ballot-ready full version by mid 2015 and publication by end of 2015
• Mostly corrections and clarifications• Currently discussing potentially switch to more efficient encoding
– Partial ballot & publication on SPaT & Map – Target Q1 2014 to support EU V2I 2015-2016 deployment
• Development of the planned J2945 Standard (currently a draft)– Target ballot-ready version by mid of 2015 and publication by end of 2015
• Timing is dependent on USDOT’s needs and maturity of technical contents
– Paired with J2735 revision publication
2013 2014 2015
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Potential J2735 J2945 Publication?
SPaT & Map Limited Release Work
J2735 Data Dict. rev
J2945 Perf. Req. rev
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SAE DSRC J2735/J2945 Development• Working on J2735/J2945 revision plan
Revise J2735 to be simply a data dictionary. (App-independent to promote reuse of data elements/frames
Revise/develop J2945 message & data performance requirements to include system engineering process, include various application needs, traceability and the data/message performance requirements as separate chapters
SAE J2735 Data Dictionary
Data Elements:•Lat/Lon•Speed•…•Signal Phase•IntersectionID•ProbeSnapShot•…
Messages:
•BSM•SPaT•Map•Probedata…
SAE J2945 Application Specific Msg/data Perf. Req
J2945.1 V2V Safety
• Con-op• User needs• Func. Req• Msg transmission Interval• Channel use• Congestion control• Security/Privacy• GPS receiver config• Data elements level req.
J2945.2? Signal Violation Warning
• Con-op• User needs• Func. Req.• Transmission interval• Channel use• Security• Data elements level req.
J2945.X ProbeData?
• Con-op• User needs• Func. Req.•…
J2945.0 Common Section• PSID
• SSP• Msg Priority
• …• …
J2945.XX
•Con-op• User needs• Func. Req.•…
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J2945.1 V2V Safety Message/Data Minimum Performance Requirements (Tentative)
•Dedicated Channel 172 for BSM (and other V-V Safety messages)-For all categories of device that conform to the accuracy requirements in this document will also use Ch172. -Signal Phase and Timing (SPaT) and Intersection Map messages will be broadcast on a channel that is to be determined.
•Congestion Mitigation - Congestion mitigation applied to all categories of devices.- Congestion mitigation requirements will be published after V2V-Interoperability project completion
•Transmission Power Requirements-Will be based on the result of scalability testing in CAMP/VSC3 V2V-Interoperability when this information is available.
•Security and Privacy Requirements-The Security and Privacy requirements for the IV, HIA and ASD will be communicated when they become available from the V2V-I & other related project
•GPS configuration Requirements-WAAS/SBAS configuration- Each GPS receiver in the MD shall be configured to use WAAS corrections.
•Data Frame/Elements Requirements-The accuracy shall be measured at the sensor output point.-The latency of a data element/frame is defined as the maximum age of the data in the outgoing BSM.
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• V2V messages:– Extend V2V messages collaboration to DENM and J2735– Potential joint work on V2Other road users, EV related ITS messages
• V2I messages: – Soon to publish SAE J2735 NEW SPaT and Map portion for EU
Deployment use– Continue monitoring regional changes potential new common
segments for future joint release
• Application specific performance requirements & test procedures– Jointly develop DSRC radio propagation performance definition and test
procedure– Data element by element level – Other opportunities
US-EU V2X Message & Data Collaboration Work-Next Steps13
• Significant achievement on collaboration of V2V and V2I message development to contribute to efficient global platform implementation
• Extending EU-US collaboration to Performance requirements and test procedure level
• Looking for experts technical contribution and field test result to further improve the quality of the standards
Summary14
Thank European and Japan expert’s strong support !