DSRC & WAVE

1

Overview• DSRC– Dedicated Short-Range Communications– ASTM Standard E2213-03, based on 802.11a– ITS communications on 5.9/5.8GHz band

• WAVE– Wireless Access in Vehicular Environments– Mode of operation used by IEEE 802.11 devices to

operate in the DSRC band• IEEE 802.11p– Based on ASTM Standard E2213-03– Currently draft

2

Comparisons

DSRC/WAVE Wi-Fi Cellular Mobile WiMAX5

Data rate 3-27Mbps 6-54Mbps < 2 Mbps 1-32 Mbps

Mobility > 60 mph < 5mph > 60 mph > 60 mph

Nominal Bandwidth 10MHz 20MHz < 3MHz < 10MHz

Operating Band 5.86-5.92GHz (ITS-RS)

2.4GHz, 5.2GHz (ISM) 800MHz, 1.9GHz 2.5 GHz

IEEE std. 802.11p(WAVE) 802.11a N/A 802.16e

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IEEE WAVE Standards

4

IEEE P1556

• Standard for Security and Privacy of Vehicle/Roadside Communication Including Smart Card Communication

• Is now replaced by IEEE 1609.2

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IEEE P1609/WAVE

• IEEE P1609 family are standards for WAVE• Defines…for vehicular wireless communication– Architecture, Communications model,

Management structure, Security mechanisms, Physical access

• Architectural components– On Board Unit (OBU)– Road Side Unit (RSU)– WAVE interface

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IEEE P1609/WAVE CCH & SCH

• WAVE devices shall be able to accommodate an architecture that supports a Control Channel (CCH) and multiple Service Channels (SCH)

• CCH– Transmit WAVE Short Messages (WSM)– Announce WAVE services

• SCH– Application interactions/transmissions

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Synchronization

• To make sure all devices are monitoring CCH during CCH interval

• IEEE 1609.2 Security• Single-channel device– Must have Coordinated Universal Time (UTC)

• Ex: GPS pulse per second (PPS)– Or it shall continuously monitoring CCH

• Multi-channel device– Monitor CCH

• Ex: Timestamp field of IEEE 802.11

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IEEE 1609 Sync Tolerance

• Guard interval is used for synchronization

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IEEE 1609/WAVE

• IEEE 1609.1– Resource Manager

• IEEE 1609.2– Security Services for Applications and

Management Messages• IEEE 1609.3– Networking Services

• IEEE 1609.4– Multi-Channel Operations

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IEEE Protocol Stacks

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WME

MLME

PLME WAVE PHY

WAVE MAC ChannelCoordination

LLC

IPv6

UDP / TCPWSMP

MIB

ToAirlink

Management Plane Data Plane

IEEE 1609.3

IEEE 1609.4

IEEE 802.11a/e/p

IEEE 1609.2

Security issues of all IEEE 1609 protocol stacks

IEEE 1609.3 Data Services

• Logical Link Control (LLC)• IPv6• UDP & TCP• WAVE short message (WSM) and protocol

(WSMP)

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IEEE 1609.3 Management Services

• Application Registration– Register application to WAVE Management Entity

(WME) so service flow can map to correct IP address & port

• WAVE Basic Service Set (WBSS) management– WBSS actions• Ex: Joining & ending a WBSS

– WBSS parameters management• Ex: SSID, MAC address, SCH number, Timestamp

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IEEE 1609.3 Management Services

• Channel usage monitoring– Ex: QoS, avoid using congested channel

• IPv6 configurations• Received channel power indicator (RCPI)

monitoring– Ex: provide RCPI for applications

• Management information base (MIB) maintenance– Management parameters

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IEEE 1609.4 User Priority (UP)

• Use IEEE 802.11e EDCA mechanism• Mapping UP to Access Category Index (ACI)

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IEEE 1609.4 UP on CCH & SCH

SCH

CCH

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IEEE 1609.4 Channel Coordination

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IEEE 802.11p

• Define enhancements to 802.11 required to support ITS applications

• Lower layer of WAVE• Supports two different stacks– IPv6• only on SCHs (not CCH)

– WAVE Short Message Protocol (WSMP)• can be sent on any channel• allows applications to directly control physical

characteristics

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IEEE 802.11p

• Communication between 802.11 STAs …– Without becoming a member of a BSS is possible– Direct & Immediate– Avoid the latency caused by BSS association– May use a dedicated frequency band

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IEEE 802.11p MAC

• DCF – CSMA/CA– IBSS & Infrastructure– Communication outside BSS

• HCF contention-based channel access => EDCA– EDCA is an enhanced variant of DCF– EDCA parameters• Outside BSS: default• Inside BSS: given by associated BSS or AP

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DSRC Worldwide - ISO

• ISO (International Organization for Standardization)– Working Group 15• Upper layer

– Working Group 16• Lower layer

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DSRC Worldwide - Europe• CEN (European Committee for Standardization)– EN 12253:2004 Dedicated Short-Range Communication -

Physical layer using microwave at 5.8 GHz (review)– EN 12795:2002 Dedicated Short-Range Communication

(DSRC) - DSRC Data link layer: Medium Access and Logical Link Control (review)

– EN 12834:2002 Dedicated Short-Range Communication - Application layer (review)

– EN 13372:2004 Dedicated Short-Range Communication (DSRC) - DSRC profiles for RTTT applications (review)

– EN ISO 14906:2004 Electronic Fee Collection - Application interface

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DSRC Worldwide - Japan

• ARIB (Association of Radio Industries and Businesses, 電波產業會 )– STD-T55: Electronic Toll Collection System– STD-T75: Dedicated Short-Range Communication

System– STD-T88: DSRC Application Sub-Layer

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DSRC Worldwide - US

Old – 915MHz• Range < 30 meters• Data rate = 0.5 mbps• Designed for ETC, but can be

used for other applications• Single unlicensed channel• Requires special (custom) chip

set & software• Vehicle to roadside

• Command-response

New – 5.9GHz• Range to 1000 meters• Data rate 6 to 27 mbps• Designed for general internet

access, can be used for ETC• 7 licensed channels• Uses open off-the-shelf chip

set & software• Vehicle to roadside & vehicle

to vehicle• Command-response & peer to

peer

The lead organization is ASTM

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US DSRC Spectrum

• 75 MHz band has been allocated by FCC at 5.9 GHz

• Initial band use rules accepted• No auction expected• Band allows both safety and commercial

applications to coexist

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US DSRC Channel Plan

Frequency (GHz)

5.85

0

5.85

5

5.86

0

5.86

5

5.87

0

5.87

5

5.88

0

5.88

5

5.89

0

5.89

5

5.90

0

5.90

5

5.91

0

5.91

5

5.92

0

5.92

5

5.82

5

5.83

0

5.83

5

5.84

0

5.84

5

Canadian Special License Zones*

US Spread Spectrum Allocation Uplink

Downlink

IEEE 802.11a/RA WB - 52 carrier OFDM /w 48 data carriers, 10 MHz channels

* - The channels overlapping these zones may be restricted in some locations in Canada. In these cases use channels 1, 2, and 3 in their place.

Ch 172 Ch 174 Ch 176 Ch 178 Ch 180 Ch 184Ch 182

Optional 20 MHz Optional 20 MHzControl Channel

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Range (ft)

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

3400

360020

0

400

600

800

Data R

ate (Mbps)

33

30

27

24

21

18

12

9

6

3

0

~

~

3000ft↓

0.5 Mbps

902 - 928 MHz Band Performance Envelope

5850 - 5925 MHz BandPerformance Envelope

Emergency Vehicle ServicesSafety Message Services

Data Transfer and Internet Access Services

Toll and Payment Services

(Approximate)

US DSRC Performance Envelope

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Specific Applications

ACCESS CONTROL PROBE DATA COLLECTION TRAFFIC INFORMATION TOLL COLLECTION GAS PAYMENT DRIVE-THRU PAYMENT DATA TRANSFER (IDB, J1708, J1939, PCI, etc.)

– ATIS DATA– DIAGNOSTIC DATA – REPAIR-SERVICE RECORD– VEHICLE COMPUTER PROGRAM UPDATES– MAP and MUSIC DATA UPDATES

RENTAL CAR PROCESSING

MAINLINE SCREENING BORDER CLEARANCE ON-BOARD SAFETY DATA TRANSFER UNIQUE CVO FLEET MANAGEMENT DRIVER’S DAILY LOG VEHICLE SAFETY INSPECTION TRANSIT VEHICLE DATA TRANSFER (gate) TRANSIT VEHICLE REFUELING LOCOMOTIVE FUEL MONITORING ROLLOVER WARNING LOW BRIDGE WARNING

IN-VEHICLE SIGNING– WORK ZONE WARNING– HIGHWAY/RAIL INTERSECTION WARNING– ROAD CONDITION WARNING

INTERSECTION COLLISION AVOIDANCE VEHICLE TO VEHICLE

– VEHICLE STOPPED or SLOWING WARNING– VEHICLE-VEHICLE COLLISION AVOIDANCE

EMERGENCY VEHICLE SIGNAL PREEMPTION TRANSIT VEHICLE SIGNAL PRIORITY EMERGENCY VEHICLE VIDEO RELAY EMERGENCY VEHICLE APPROACH WARNING

Private and Public Safety - Short Range CVO

Private and Public Safety - Short Range ALL VEHICLES

Public Safety - Extended Range

Public Safety - Intersection and Emergency

TOLL COLLECTION TRANSIT VEHICLE DATA TRANSFER (yard) LOCOMOTIVE DATA TRANSFER CVO TRUCK STOP DATA TRANSFER

Private and Public Safety - Large Zone

Illustrations of some US DSRC APPs• Roadside Unit Placement• Good News/ Bad News• General Internet Access• On-Demand/Dynamic Navigation• Traffic Advisories• Use Vehicles as Traffic Probes• Travel Assistant• Relayed & Delayed Transmission

1. Information or Transaction Request2. Information Requested over Internet3. Data Downloaded Later

Pictures of these applications are selected from Lee Armstrong’s DSRC introduction website29

Roadside Unit Placement

Sometimes someplace instead of everywhere always30

Good News/ Bad News

Can be targeted to specific lanes, directions of travel but not for wide area coverage

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General Internet Access

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On-Demand/Dynamic Navigation

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Traffic Advisories

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Use Vehicles as Traffic Probes

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Travel Assistant

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Relayed & Delayed Transmission

1. Information or Transaction Request2. Information Requested over Internet3. Data Downloaded Later

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Information or Transaction Request

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Information Requested over Internet

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Data Downloaded Later

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