Dedicated Short Range Communications - IEEE · PDF file · 2014-07-03Dedicated...

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Dedicated Short Range Communications:Connecting vehicles

John KenneyToyota InfoTechnology Center, USA

June 11, 2014jkenney@us.toyota-itc.com

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33,561 2012Traffic Fatalities in

What if …

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we could use wireless communicationto make driving safer?

DSRCDedicated Short

Range Communication

80%US DOT estimates DSRC can

address 80% of crashes involvingnon-impaired drivers

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DSRC Outline

• What is it?• What is it good for?• How does it work?• What’s hard about this?• What happens next?

What is DSRC?

• Ad hoc networking to and from vehicles– V2X where X = {vehicle, roadside infrastructure,

phone, bicycle, train, pedestrian …}

• Part of the Intelligent TransportationSystem (ITS)

• Key for US DOTConnectedVehicleprogram

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What is DSRC Good For?

• Saving Lives• Preventing or reducing:

– Injuries– Property destruction– Time lost in traffic– Fuel consumption/Greenhouse gas emissions

• Enabling mobile commerce• Informing drivers• Creating sandbox for innovation …

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DSRC V2V Safety Concept• Concept: each vehicle

sends Basic SafetyMessages frequently.

• Receiving vehiclesassess collision threats

• Threat: Warn driver ortake control of car

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Example collision scenarios

• All enabledby exchangeof BSMs

• Receiverapps notstandard

• Innovativeuses of BSMencouraged

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Emergency Electronic Brake Lights (EEBL)

Forward Collision Warning (FCW)

Blind Spot / Lane Change Warning (BSW / LCW)

Do Not Pass Warning (DNPW)

Intersection Movement Assist (IMA)

Left Turn Assist (LTA)

Roadside use case:Work Zone Warning

Grass Divider

up to 1100 ftrange

Work Zone Warning Com. Zone

Work Zone

Traffic Cones

RSU

In-Vehicle Displayand AnnunciationZONE

AHEAD

WORK

9RSU = Roadside Unit

V2I Safety Use Case:Emergency Signal Preemption

EmergencyVehicle

RSU

up to 1000 m(3281 ft)

Preempt Transaction1. DSRC OBE-to-RSE: Vehicle Host Preemption Request2. DSRC RSE-to-OBE: ACK3. Emergency Vehicle Host Displays Preempt-ACK within vehicle

DSRC Transaction occurs on Ch. 184 at high power.

OBU

10OBU = On Board Unit, RSU = Roadside Unit

How does DSRC Work?• Necessary for interoperability

DSRC PHY+MAC (IEEE 802.11p)

DSRC Upper-MAC (IEEE 1609.4)

IPv6

TCP/UDP

Safety Message (SAE J2735)Min. Perf. Req. (SAE J2945)

Non-safety applications

DSRC Security (IE

EE

1609.2)

DSRC WSMPwith safety sublayer

(IEEE 1609.3)

See: J. Kenney, “DSRC Standards in the United States”, Proc. IEEE, July 2011, Vol. 99, No. 7, pp. 1162-118211

• Most standards mature

DSRC System

InternalSensors

Computer

DSRCRadio

GPS

DriverInterface

Example of DSRC Prototype SystemMany suppliers are in this space

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DSRC Spectrum

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Frequency(GHz)

Ch 172BSMs

Ch 174 Ch 176 Ch 180 Ch 184PublicSafety

Ch 182Ch 178ControlChannel

Long Range

Intersections

Control

Channel

Designated Public SafetyShort Range

Service

Shared Public Safety /Private Service

40 dBm

33 dBm

23 dBm

40.0

33.0

23.0

44.8 dBm

Public limit

Private limit

Medium Range

Service

V2V and

Safety of Life

44.8

5.85

0

5.85

5

5.86

5

5.87

5

5.88

5

5.89

5

5.90

5

5.91

5

5.92

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PowerLimits(dBm EIRP)

Recent move to allow unlicensed sharing discussed below

What is hard about DSRC?

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Mobility:• Testing shows

802.11p capableof dependablecommunicationover ~300 meters@ 20 dBm

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Scalability

Basic question: will all this still work here?

Distributed Adaptive Control

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Each vehicle computesits message rate ri(t)adaptively based onchannel load

Vehicle KMessage Rate Control System

Vehicle 1Message Rate Control System

DSRC Channel

r1(t)

rK(t)

CBR(t)

Algorithm Goals: controlled load, convergence, fairness

Σ+

_

CBR TargetCBR Target isassociated with highchannel throughput

CBR = Channel Busy RatioA channel loading metric

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Adaptive Algorithm: LIMERIC• LInear MEssage Rate Integrated Controller• Toyota ITC idea• Currently under evaluation in US and Europe

See: G. Bansal, J. Kenney, and C. Rohrs, “LIMERIC: A Linear Message Rate Control Algorithm for DSRCCongestion Control”, IEEE Transactions on Vehicular Technology, to appear fall 2013.

Convergence:• Provable conditions• Fair• Exact

• Mathematicallyprovable behavior

• Demonstrated viasimulation

• Verified by radioimplementation

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Security and Privacy

• Goals:– Receiver needs to trust information it gets– We need to preserve privacy of drivers– Costs need to be controlled

• Two principal areas:– Per-message security– Security Infrastructure

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Per-Message Security

• IEEE 1609.2 standard defines how toauthenticate and how to encrypt

• Authentication proves– Sender was authorized– Content was not changed

• No permanent identifiers are included

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Get/Renew credentials?Detect misbehavior?Remove bad actors?

Security Infrastructure

CertificateAuthority (CA)

New CertificatesCertificateRevocation Lists

MisbehaviorReports

What medium?

Status of DSRC Deployment

• 10+ years of research (US DOT, industry)• Standards are mature• Aug. 2012-Aug. 2013 Model deployment

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• Testing collisionavoidance

• ~3000 DSRCequippedvehicles

• Includes cars,trucks, buses,motorcycles

• > 20infrastructurelocations

• 100s GB datacollected

• > 10 TB videocollected

What happens next for DSRC?

• Feb. 3, 2014: NHTSA planto require DSRC

– http://www.nhtsa.gov/About+NHTSA/Press+Releases/USDOT+to+Move+Forward+with+Vehicle-to-Vehicle+Communication+Technology+for+Light+Vehicles

– Regulatory process is starting

• US DOT expanding test beds and field trials:– Michigan, Florida, New York, California– http://www.its.dot.gov/testbed.htm

• Engagement from suppliers• OEMs ramping development• Technical challenges remaining:

– Spectrum Sharing– Global harmonization– Protocol evolution– Automated control

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Conclusions

• DSRC has great potential to make drivingsafer: 33,561

• DSRC can enable many other services,including automated driving

• Technology is relatively mature• US DOT planning to require DSRC• Remaining challenges include:

– Congestion Control (Scalability)– Security– Spectrum Sharing 23

24jkenney@us.toyota-itc.com

www.us.toyota-itc.com