Vehicle Positioning, Digital Maps and Integrated Services

Lecture 7 WAVE Protocols

Outline

WAVE IntroductionWAVE1609.1WAVE1609.2WAVE1609.3WAVE1609.4

Introduction

DSRC5.9GHz DSRCMACPHYIEEE802.11p.802.11pIEEE2003802.11aWAVE(Wireless Access in the Vehicular Environment)DSRC

Introduction

ITSDSRC

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Introduction

: Bluetooth (BT), Ultra-wideband (UWB)

: 2G, 2.5G, 3G, 3.5G (cellular systems), GPS, WiMAX

: Microwave, Infrared, Dedicated Short Range Communications (DSRC), Wi-Fi

: Microwave, Infrared, DSRC

Introduction

(microwave)(infrared)(radio frequency, e.g. DSRC)

Introduction

(V2R, OBU-to-RSURSU-to-OBU)

(V2V, OBU-to-OBU)

DSRC

DSRCITSDSRCOBURSU

1050 m (line-of-sight) kbps

Wi-Fi WLAN: 10100 m ideal: a: 54Mbps11b: 11 Mbps11g: 54 Mbps DSRC WLAN: 3001000 m mobile: 327 Mbps

DSRC/WAVE

Vehicle to vehicle

Service channel

Service channel

Control channel

Intersection

10MHz5.855~5.925GHz5.890GHz()5.860GHz()

DSRC/WAVE

DSRC/WAVEIPIEEE1609.3/WAVE Short Message ProtocolIPv6

*

*

WME

UDP/TCP

WSMP

LLC

WAVE MAC

WAVE Physical

Management plane

Data plane

WAVE Protocol Stack Model

IPv6

1609.3

MLME

PLME

Multi-channel operation

1609.4

1609.3

802.11p

802.2

Application

1609.1

ApplicationPresentationSession

Network

Data Link

Physical

Transport

OSI Reference Model

802.11

Security

Services

1609.2

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IEEE1609 IEEE 1609 5.9 GHz IEEE 802.11 802.11p IPv6

IETF (Internet Engineering Task Force) WAVE

LLC (Logical Link Control ) -- IEEE 802.2LLCMAC (Medium Access Control) -- PHY (Physical Layer) -- WME (WAVE Management EntityWAVE )MLME (MAC Layer Management Entity)PLME (Physical Layer Management Entity)WSMP (WAVE Short Message ProtocolWAVE )MAC sublayer management entity (MLME)physical sublayer management entity (MLME)

Noun interpret(1)

Wireless access in vehicular environment (WAVE): IEEE

Onboard unit (OBU):WAVERSUOBU

Roadside unit (RSU):WAVEOBUs

Noun interpret(2)

Provider Service Table (PST):WAVE devicechannel

Provider Service Context (PSC):PSID

Provider service identifier (PSID)

Noun interpret(3)

WAVE management entity (WME):WAVE networking

WAVE short message (WSM):IPWAVE device

WAVE short message protocol (WSMP): WAVE shot message

Noun interpret(4)

WAVE basic service set (WBSS)WAVESCHWBSSWAVEWAVECCH

WAVE routing advertisement (WRA):RSU

Noun interpret(5)

WAVE service advertisement (WSA)WAVEWMEWAVE

WAVE service information element (WSIE)WAVEWAVE

System components and connectivity

Two types of systems identified in the WAVE standards. The first type is a roadside unit (RSU). The second type is an onboard unit (OBU).

WAVE(RSU)(OBU)

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IEEE 1609.1

IEEE 1609.1 : resource manager IEEE 1609.1 WAVE DSRC WAVE (OBU) (RSU) WAVE

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IEEE 1609.2

IEEE 1609.2 : secure message formats to process secure messages of the DSRC/WAVE DSRC WAVE

WAVE

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Scope & purpose

Define secure message formats, the processing of the secure messages within the DSRC/WAVE systemMethod for securing WAVE management messages and application messages excepting vehicle-originating safety messagesServices used to protect messages from attacks

WAVE systems overview

Entities in the systemProvidersUsersRoadSide Units (RSUs) WAVE devices operate only when stationarySupport information exchange with OBUsUsually be providersOn-Board Units (OBUs)WAVE devices operate in motionSupport information exchange with RSUs and other OBUsUsually be users (may be providers)Public Safety On-Board Units (PSOBUs)Certificate Authorities (CAs)Support security servicesAuthorize other entities via the issuance and revocation of certificates

WAVE systems overview

WAVE systems overview-Messages for WAVE radio stack

WAVE Short Message (WSM) for broadcast applications over WSMP (network layer)UDP/IP stack for transactional applications (network layer)WAVE Service Announcement (WSA) for providers notifies users which the services are and what service channel(s) they are provided on (MAC layer)All generated by the WAVE Management Entity (WME)

WAVE systems overview Security services

Applications over UDP use the secured message formats to protect application data (Encrypted Message)Application over WSMP use the secured message formats or the secured WSM types to protect application data (Signed Message)WME uses the secured WSIE type to preventing fake services (Signed Message)

Secured message format

Secured message format

Secured message format

Secured message format

Secured message format

Secured message format

Secured message format

Secured message examples

Secured message examples

Communication security overview

AttacksIntercept a messageAlter the messageReplay a messagePreventionConfidentiality encrypting the messageAuthenticity confirmation of origin of the messageIntegrity confirmation that the message has not been altered

Cryptographic services

Symmetric algorithm (secret-key)Two entities share a secret-key and uses this key to encrypt/decrypt the message and provide authenticity and integrityOnly the party shares the key knows who generates the messageAES-CCM (authenticate-then-encrypt) adopted by this standard Asymmetric algorithm (public-key)Two keys: public key and private keyIn WAVE context, broadcast messages are signed and are not be encryptedTransactional messages are protected with asymmetric or symmetric algorithms

Cryptographic services

Hash functionsSHA-1 are adopted by this standardUse to generate identifiers to certificates and fragmented messagedFor efficiently operate the cryptographic algorithmAsymmetric algorithms are used to setup a secure-sessionSymmetric algorithms are then used to protect data

The construction and use of signed messages

Flow Chart

Issuer requests certificate from CA

CA response with corresponding certificate and CRL

WAVECertificateRequest

WAVECertificateResponse

Sender send signed message with certificate and signature

Receiver verifies the message by certificate and the signature

SecuredMessage(Signed Message)

Sender send encrypted message

Receiver decrypts the message by symmetric key

SecuredMessage(Encrypted Message)

Summary of IEEE 1609.2

Anonymity

Mechanism for providing anonymous authenticated broadcast messaged are not given in this standard at this timeThe current standard is focus on protecting message payloads and does not provide the protection for message headers

IEEE 1609.3

IEEE 1609.3 : network services WAVE WAVE WAVE OSI IEEE 1609.3 IPv6 WAVE short message (WSM)

*

WAVE network services (1/3)

IEEE 1609.3 WAVE

IEEE 1609.3 5.9GHz DSRC/WAVE

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WAVE network services (2/3)

WAVE Data Plane() UDP (TCP)IPv6 WAVE Short Message (WSM) Protocol (WSMP) WAVEIPv6WSMP

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WAVE network services (3/3)

Management Plane()

(WAVE basic service set ,WBSS)

IPv6

*

Communication protocols (1/2)

Channel typesCCH (single control channel)shorthigh-priority application system control message SCH (multiple service channel)

*

WAVE-- WSMP IPv6

- CCH shorthigh-priority application system control message

- SCH

Communication protocols (2/2)

WAVE Short Message Protocol (WSMP)WAVE (CCH or SCH) PHY()WAVE Short Messages (WSMs)PSID

IPv6SCH

*

WAVE

- WSMP WSMPWSMPWAVE (CCH or SCH) PHY()

WSMsMAC addressbroadcast addressWSMs PSID WSMs

- IPv6SCH

IEEE1069.3 Protocol Stack Model

non-IP based

*

IEEE 1609.3 WAVE system IP non-IP based non-IP basedWSMPIEEE 1609.3 WAVE WME MIB LLCUDP/TCPWSMP

Datagram different in TCP/IP and WSM( Wave Short Message )

LLCIEEE 802OSIMACLLCIEEE 802.3MACLLCIEEE 802.2LLC DSAP(Destination Service Access Point)SSAP(Source Service Access Point)(Control)DSAPSSAP DSAPSSAP

SNAP(Sub-Network Access Protocol)LLC HeaderDSAPSSAP64SNAP CodeTypeCodeTypeEthernet IITypeSNAPLLCDSAP SSAP0XAAControl0X03

Logical Link Control (LLC)

IPv6 type packets received from the lower layers with an Ethernet Type value of 0x86DD are delivered to the IPv6 protocol. WSM packets received from the lower layers with an Ethernet Type of 0x88DC are delivered to the WSM protocol. IPv6 packets for transmission shall have Ethernet Type set to 0x86DD. WSM packets for transmission shall have Ethernet Type set to 0x88DC

IPv6Ethernet Type0x86DD

WSMEthernet Type0x88DC

Service request summary table & graph

alternating

immediate

extended

CCHCCH intervalSCH intervalCCHSCHNetworking ServicerequestSCHCCH intervalCCHSCH interval

Service access point

Service access point (SAP)protocol layer

WAVE Basic Service Set (WBSS)

WBSSWAVEWBSS WBSS

WSMPWBSSSCHWSMsCCH

WAVE Communications Concepts

WBSSWBSSWSMsCCHWBSSWSMsIPv6SCHWBSS(persistent)(non-persistent)Internet accessDevice WBSS rolesWBSSrolePrioritiesWMEMAC

Operation without a WBSS

WSMMACWSMPpower leveldata rateWSMWSMPCCHpacket passcommunication stackWSMPPSIDCCH

Operation with a WBSS (1/2)

WBSS Persistent WBSSCCH

Non-Persistent WBSS

Operation with a WBSS (2/2)

WAVE Service Information Element (WSIE)WAVEWSIEWAVE Service Advertisement (WSA)WSIEWBSSWMEWME-Application.request WMEMLME-WSA.request WBSS

WAVE Service Information Element (WSIE)

Reference by IEEE 1609.3

*

WSIE WAVEWMEProvider Service InfoChannel InfoWAVE Routing Advertisement WRA()WAVE Service Advertisement WSA IEEE 1609.2Security HeaderTrailerSecured WSApackageMLME-WSA.requestMLMEMLMEtiming quality headerWSIEMAC header trailer

Service usage examples(1/4)

Higher layerentityprovider service request WMESCHMLMEWSAs

Service usage examples(2/4)

Higher layerentityuser service requestSCHWMEWSAsdetectSCH

Service usage examples(3/4)

Higher layerentityuser service request no SCH accessWMEWSAsHigher layerHigher layerMIBservice requestauto-accessWMEauto-accessSCH access

Service usage examples(4/4)

Higher layerentity user servicerequestWMEMIBWMESCH access

Wave Service Advertisement format

Provider Service InfoService InfoChannel InfoWAVE Routing

WSM format

Provider Service Identifier (PSID) WSM

WAVE Element IDWSMElement ID

WSMLength WSM data

WSMData WSMData

WAVE Element ID

WAVE Element ID

IEEE 1609.4

Discuss the WAVE multi-channel operationsMAC (Control Channel, CCH) (Service Channels, SCH) ()

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General description

WAVE (OBU RSU) (CCH) (SCH)CCHWSMWAVESCHs(Physical layer, PHY) IEEE 802.11 IEEE 802.11p

Reference Model

WME

UDP/TCP

WSMP

LLC

WAVE MAC with channel coordination

WAVE Physical

Management plane

Data plane

IPv6

MLME

PLME

Application

Focus of enhancements

Specified by this standard

*

IEEE 1609.4 MLME WAVE MAC with channel coordination MLME MAC (MAC sublayer management entity) (multi-channel) IEEE 802.11 MACLLC (logical link control IEEE802.2) PHY (IEEE P802.11p)

Multi-channel operation(1/3)

(1) PHY is tuned to the CCH, and receives WSAs, which are in turn passed to MLME, and then WME.(2) WME accepts user service requests from higher layer entities.(3) WME matches available services with requested services and assigns channel access, sending SCH start commands to the MAC layer management entities associated with the two physical layers.

PHYCCHWSAsMLMEWME

WME

WMEMLMEPHY

Multi-channel operation(2/3)

(4) MLME controls the channel switching of the two PHYs. PHY1 alternates between CCH and SCH1 on channel interval boundaries; PHY2 remains tunes to SCH2 for the duration of its service.(5) On receipt of a subsequent request from the higher layer, WMEends the SCH2 assignment and MLME in turn causes PHY2 to return to its default state.

MLMEPHYPHY1CCHSCH1channel intervalPHY2SCH2

WMESCH2PHY2default

Multi-channel operation(3/3)

Provide Functions

(Channel routing)Routing for WSMP dataRouting for IP datagram(User priority, UP)(Channel coordination)MAC(MSDU)

Routing for WSMP data (1/2)

WSMP header channel numberpower level data rateData Packet IEEE 1609.3

*

WSMP (WAVE short message protocol) data

WSMP header , Channel numberPower level Data rate

1 octet = 8

Routing for WSMP data (2/2)

Routing Script Scenario WSMP data LLC MAC MAC buffer WSMP header channel number WSMP header channel number channel number CCH number SCH number

*

WSMP (WAVE short message protocol) data

1. WSMP data LLC MAC

2. MAC buffer WSMP header channel number

3. WSMP header channel number channel number CCH number SCH number

Routing for IP packet (1/2)

IP MLME SCH numberpower leveldata rate power level data rate

IP LLC MACMACSCH

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IP

IP MLME SCH numberpower leveldata rate power level data rate

IP LLC MACMACSCH

Routing for IP diagrams (2/2)

Data shall be discarded WAVE WBSS (WAVE basic service set) WBSSWAVESCH

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WAVE WBSS (WAVE basic service set) WBSSWAVESCH

User priority (1/2)

IEEE 802.11e (Enhanced Distributed Channel Access mechanism EDCA) (MAC) (access category index, ACI)IEEE 802.11 EDCA parameters(Arbitration inter-frame spaceAIFS)(Contention windowCW)(Transmit opportunity (TXOP) limit) TXOPlimit =0MSDU

User priority (2/2)

Channel (MAC)

LLC

PHY

MAC

ACI = 0

ACI = 1

ACI = 2

Transmit Queues

AIFS[ACI]

CW[ACI]

TXOP[ACI]

Internal Contention

Medium Contention

Source : IEEE 1609.4

AIFS[ACI]

CW[ACI]

TXOP[ACI]

AIFS[ACI]

CW[ACI]

TXOP[ACI]

ACI = 3

AIFS[ACI]

CW[ACI]

TXOP[ACI]

Pre-queue channel access functions

*

Channel (PHY)

MSDU MAC Channel routing MAC (ACI)

(back-off)

-

ITS1986U. C. BerkeleyPATHVIIGMV2VIVBSS(Integrated Vehicle-Based Safety System)CICAS(Cooperative Intersection Collision Avoidance System)VII(Vehicle Infrastructure Integration)(Vehicle Safety Communication Consortium, VSCC)

*

-

ITS1970ASV(Advanced Safety Vehicle)AHS(Advanced cruise-assisted Highway System)

*

-

ITS

FleetNetIVHW (Inter-Vehicle Hazard Warning)CarTALK 2000WILLWARN (Wireless Local Danger Warning)COMeSafetyIntelligent Car Initiative

2003 (C2C-CC, Car-to-Car Communication Consortium)

*

*

DSRCITSDSRCOBURSU

10MHz5.855~5.925GHz5.890GHz()5.860GHz()

DSRC/WAVEIPIEEE1609.3/WAVE Short Message ProtocolIPv6

*

*

IEEE1609 IEEE 1609 5.9 GHz IEEE 802.11 802.11p IPv6

IETF (Internet Engineering Task Force) WAVE

LLC (Logical Link Control ) -- IEEE 802.2LLCMAC (Medium Access Control) -- PHY (Physical Layer) -- WME (WAVE Management EntityWAVE )MLME (MAC Layer Management Entity)PLME (Physical Layer Management Entity)WSMP (WAVE Short Message ProtocolWAVE )MAC sublayer management entity (MLME)physical sublayer management entity (MLME)

WAVE(RSU)(OBU)

*

*

*

*

*

*

*

WAVE-- WSMP IPv6

- CCH shorthigh-priority application system control message

- SCH

*

WAVE

- WSMP WSMPWSMPWAVE (CCH or SCH) PHY()

WSMsMAC addressbroadcast addressWSMs PSID WSMs

- IPv6SCH

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IEEE 1609.3 WAVE system IP non-IP based non-IP basedWSMPIEEE 1609.3 WAVE WME MIB LLCUDP/TCPWSMP

LLCIEEE 802OSIMACLLCIEEE 802.3MACLLCIEEE 802.2LLC DSAP(Destination Service Access Point)SSAP(Source Service Access Point)(Control)DSAPSSAP DSAPSSAP

SNAP(Sub-Network Access Protocol)LLC HeaderDSAPSSAP64SNAP CodeTypeCodeTypeEthernet IITypeSNAPLLCDSAP SSAP0XAAControl0X03

IPv6Ethernet Type0x86DD

WSMEthernet Type0x88DC

CCHCCH intervalSCH intervalCCHSCHNetworking ServicerequestSCHCCH intervalCCHSCH interval

Service access point (SAP)protocol layer

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WSIE WAVEWMEProvider Service InfoChannel InfoWAVE Routing Advertisement WRA()WAVE Service Advertisement WSA IEEE 1609.2Security HeaderTrailerSecured WSApackageMLME-WSA.requestMLMEMLMEtiming quality headerWSIEMAC header trailer

Higher layerentityprovider service request WMESCHMLMEWSAs

Higher layerentityuser service requestSCHWMEWSAsdetectSCH

Higher layerentityuser service request no SCH accessWMEWSAsHigher layerHigher layerMIBservice requestauto-accessWMEauto-accessSCH access

Higher layerentity user servicerequestWMEMIBWMESCH access

Provider Service InfoService InfoChannel InfoWAVE Routing

Provider Service Identifier (PSID) WSM

WAVE Element IDWSMElement ID

WSMLength WSM data

WSMData WSMData

WAVE Element ID

*

*

IEEE 1609.4 MLME WAVE MAC with channel coordination MLME MAC (MAC sublayer management entity) (multi-channel) IEEE 802.11 MACLLC (logical link control IEEE802.2) PHY (IEEE P802.11p)

PHYCCHWSAsMLMEWME

WME

WMEMLMEPHY

MLMEPHYPHY1CCHSCH1channel intervalPHY2SCH2

WMESCH2PHY2default

*

WSMP (WAVE short message protocol) data

WSMP header , Channel numberPower level Data rate

1 octet = 8

*

WSMP (WAVE short message protocol) data

1. WSMP data LLC MAC

2. MAC buffer WSMP header channel number

3. WSMP header channel number channel number CCH number SCH number

*

IP

IP MLME SCH numberpower leveldata rate power level data rate

IP LLC MACMACSCH

*

WAVE WBSS (WAVE basic service set) WBSSWAVESCH

*

Channel (PHY)

MSDU MAC Channel routing MAC (ACI)

(back-off)

ITS1986U. C. BerkeleyPATHVIIGMV2VIVBSS(Integrated Vehicle-Based Safety System)CICAS(Cooperative Intersection Collision Avoidance System)VII(Vehicle Infrastructure Integration)(Vehicle Safety Communication Consortium, VSCC)

*

ITS1970ASV(Advanced Safety Vehicle)AHS(Advanced cruise-assisted Highway System)

*

FleetNetIVHW (Inter-Vehicle Hazard Warning)CarTALK 2000WILLWARN (Wireless Local Danger Warning)COMeSafetyIntelligent Car Initiative

2003 (C2C-CC, Car-to-Car Communication Consortium)

*

Vehicle to

vehicle

Service

channel

Service

channel

Control

channel

Intersection

CH

172

CH

174

CH

182

CH

180

CH

178

CH

176

CH

184

5

.

8

5

5

5

.

9

2

5

5

.

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1

5

5

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5

5

.

8

9

5

5

.

8

8

5

5

.

8

7

5

5

.

8

6

5

Frequency

(

GHz

)

Optionally combined

service channels

Issuer requests

certificate from CA

CA response with

corresponding certificate

and CRL

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Sender send signed

message with certificate

and signature

Receiver verifies the

message by certificate

and the signature

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Sender send encrypted

message

Receiver decrypts

the message by

symmetric key

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