US-EU V2V V2I Message Set Standards Collaboration

Sue Bai

Honda R&D Americas, Inc.

2013-02-12

1

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

2

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)

4

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

5

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

6

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

7

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.•…

11

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.

12

• 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 !

• Questions?

Thank you!

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