Redes Inalámbricas – Tema 5 Vehicular Networking

REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA

Redes Inalámbricas – Tema 5 Vehicular Networking

General overviewTechnologies

WAVE CALM

Mobility

Thanks to:• Knut Evensen - CVIS Chief Architect• John Moring • Vinod Kone• Jeonghoon Mo @ WINE LAB, Information and Communications University

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102

Motivation

Safety and transport efficiency In Europe around 40,000 people die and more than 1.5

millions are injured every year on the roads Traffic jams generate a tremendous waste of time and of

fuel Most of these problems can be solved by providing

appropriate information to the driver or to the vehicle

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10 Motivation: other scenarios3

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10 Motivation: other scenarios4

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105

Motivation: Sensor networks on the road

Position sensorsGPS, accelerometer,

compass, tilt sensorEnvironment sensors

CO2, cameras, thermometer, barometer, humidity sensor

Vehicle sensors ignition, speed, engine

speed, engine temperature, …

Vehicle interior sensorscamera, ID card reader

Source: Davies, Cottingham, Jones: A Sensor Platform forSentient Transportation Research, LNCS 4272. Oct. 2006.

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Technology trends Wi-Fi (and possibly WiMAX) enabled

vehicles are expected to be on the road within the next 3-5 years. Assuming 10% market penetration, this amounts to ~3-4 million Wi-Fi enabled vehicles in the UK, and ~20 million in the US in near future.

FCC has allocated 75 MHz of spectrum exclusively for V2V and V2I wireless communications (total UK 3G spectrum is ~ 70 MHz). In the UK and across the EU 30 MHZ of spectrum has been put aside for vehicular networks.

Vehicles equipped with WiFi can communicate directly with each other (V2V), and with the fixed infrastructure (V2I). They can form Vehicular Adhoc Networks (VANET)

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107

Vehicular Ad Hoc Network (VANET)

Vehicular Ad Hoc network (VANET) Uses equipped vehicles as the network nodes Nodes move at will relative to each other but within the

constraints of the road infrastructure VANETs vs MANETs

Rapid Topology ChangesHigh relative speed of vehicles => short link life

Frequent FragmentationChunks of the net are unable to reach nodes in nearby regions

Small Effective Network DiameterA path may cease to exist almost as quickly as it was

discovered (reactive routing) Limited Redundancy

The redundancy in MANETs is critical to providing additional bandwidth

In VANETs the redundancy is limited both in time and in function

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10 So what kind of a system do we need?

Desirable system properties Data collection and distribution in a local environment Low information delivery latency Cheap deployment and communication

Probable solutions Cellular ? Service fees Satellite ? High latency Vehicular Networks ?

What is a vehicular network? Vehicles are equipped with sensing, computing and wireless

devices Vehicles talk to road-side infrastructure (V2I) and other vehicles

(V2V) Has all the desirable properties

8

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10 Vehicular Networks

What does road-side infrastructure (Infostation) mean? High bandwidth & Low cost device Coverage is less compared to a cellular base station

Advantages of infrastructure support Low latency communication with vehicles Gateway to the Internet and extend connectivity Distributing time-critical data (e.g. accident notifications, traffic

jam) near the affected area is efficient

9

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1010 Data Dissemination approaches and tradeoffs

CharacteristicsHigh mobilityDynamic topologyReceivers are a priori

unknownLarge scaleHigh densityLow penetration ratio

ChallengesMaintaining routing

tables is difficult

Scalability

Dealing with partitions

Vehicular networks need to handle large amounts of data (emergency messages, videos etc)How do we efficiently disseminate this information?

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1011 Classification of Dissemination Approaches

V2I / I2V dissemination Push based Pull based

V2V dissemination Flooding Relaying

How to deal with network partitions? Opportunistic forwarding

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10 Push based dissemination

Infostation pushes out the data to everyone Applications: Traffic alerts, Weather alerts

Why is this useful? Good for popular data No cross traffic Low contention

Drawback Everyone might not be interested in the same data

12V2I / I2V dissemination Push based Pull basedV2V dissemination Flooding RelayingHow to deal with network partitions? Opportunistic forwarding

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10 Pull based dissemination

Request – Response model Applications: Email, Webpage requests

Why is this useful? For unpopular / user-specific data

Drawback Lots of cross traffic Contention, Interference, Collisions


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10 Flooding

Basic Idea Broadcast generated and received data to neighbors Usually everyone participates in dissemination

Advantages “Good” for delay sensitive applications Suitable for sparse networks

Key Challenges How to avoid broadcast storm problem?


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10 Techniques to avoid the broadcast problem

Simple forwarding Timer based Hop limited

Map based / Geographic forwarding Directed flooding Aggregation

Drawbacks / Limitations of Flooding Flooding in general

High message overhead Not scalable Map based / Geographic

Geographically closest doesn’t necessarily reflect the best path!

Depend on a location based serviceAggregation techniques tradeoff with accuracy


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10 Relaying

Basic Idea Instead of flooding the network, select a relay (next hop) Relay node forwards the data to next hop and so on

Advantages Reduced contention Scalable for dense networks

Key Challenges How to select the relay neighbors? How to ensure reliability?


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10 How to select a relay neighbor?

Simple forwarding Select the node farthest from source

Map based / Geographic forwarding Closest to the destination Abstract topology into a weighted directed graph

Drawback / Limitations Locally best next hop may not be globally best !


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10 How to ensure reliability?

Use RTS/CTS & ACK

Use indirect acknowledgments

Drawbacks / Limitations RTS/CTS incurs lot of overhead Interference affects indirect acknowledgments


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10 Opportunistic Forwarding

Problem with partitioned networks Next hop is not always present

Opportunistic Forwarding Basic Idea: Store and Forward Challenge: What is the right re-broadcast interval?

Solutions Broadcast repeatedly Cache at infostations


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10 Opportunistic: Drawbacks / Limitations

It is difficult to select the correct re-broadcast interval Too soon high overhead Too late doesn’t deal with partitions effectively

Maintaining a neighbor list induces high overhead and contention


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10 Take AwayV2I/I2V Dissemination Pros Cons

Push Suitable for popular data Not suitable for un-popular data

Pull Suitable for un-popular/ user-specific data

Cross traffic incurs heavy interference, collisions

V2V Dissemination Pros ConsFlooding Can reliably & quickly

distribute data Not scalable for dense networks

Relaying Works well even in dense networks

Selecting best next hop & reliability is difficult

Dissemination in Partitioned networks

Pros Cons

Opportunistic Suitable for network partitions

Difficult to estimate re-broadcast intervalHigh overhead in dense networks

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1022 EU activities

Group of Experts IEEE

European

Projects

Harmonization Standardisation

Political, Social and Economic Interests

ETSI

ITUISO

C2C-CC

ConveningStimulationModerationEditoring

Dissemination

CombinationClarification

Spec

ifica

tions

CEN

Etc.

IETF

http://www.coopers-ip.eu/index.php?id=2

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1023 Numerous Systems and Standards are under

Construction…

A variety of EU and national projects elaborate Protocol Architectures,System Architectures, High-Level Architectures .......

Do we really need yet another Communication - Architecture ?

Yes, because a comprehensive framework is needed to enable individually developed components to cooperate easily

Source: Timo Kosch, BMW

http://www.prevent-ip.org/en/home.htm

http://www.coopers-ip.eu/index.php?id=2

http://www.network-on-wheels.de/vision.html

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1024 Proposed European ITS Communication Architecture

Facilities

Station-ExternalInterfaces

MI-S

AP

IN-SAP

Man

agem

ent I

nfor

mat

ion

Bas

e (M

IB)

Station-InternalInterfaces

ITS Network

IN-SAP

MN

-SA

P

Networking & Transport

Access Technologies (PHY&DLL)

...IPv6 +Mobility

Extensions

NF-SAP

Geo-Routing

MI-S

AP

MN

-SA

PM

F-S

AP

Man

agem

ent

Application Support

NF-SAP

MF-

SA

P

ITS Station Reference Architecture

Other protocols

e.g.GPS

e.g.2G/3G/...

e.g.BlueTooth

e.g.Ethernet

e.g.5.9GHz

Secu

rity

SI-S

AP

SI-S

AP

SN

-SA

P

SN

-SA

P

SF-

SA

P

SF-

SA

P

Sec

urity

Info

rmat

ion

Bas

e(Id

entit

y, C

rypt

oKey

and

Cer

tific

ate

Man

agm

ent)

Session Support

SM-SAP

ITS Transport TCP/UDP

e.g.WiFi

Information Support

ApplicationsTraffic

EfficiencyRoadSafety

OtherApplications

FA-SAP

SA

-SA

P

SA

-SA

P

MA

-SA

P

MA

-SA

P

FA-SAP

SM-SAP

Hardware Security Module (HSM)

Aut

hent

icat

ion,

Aut

horiz

atio

n, P

rofil

e M

anag

emen

t

Fire

wal

l and

Intru

sion

Man

agem

ent

Cro

ss-In

terfa

ce M

anag

emen

tN

etw

orki

ng M

anag

emen

tS

tatio

n m

anag

emen

t

Joint development: ETSI TC ITS COMeSafet

y+ R&D projects




WAVE CALM

Mobility


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10

26

Wireless technologies for BWA Wi-Fi

802.11a/b/g 3G WiMAX 802.16d/e

DSRC 802.11p ( WAVE)

Range up to1000 m up to 4 km up to 40 km Up to 250 m

data rate 11-54 Mbps 384 Kbps – 2Mbps, 14Mbps

10-100 Mbps 54 Mbps

spectrum 2.4 GHz (b/f) 5.2 GHz (f)

1900 to 1980 MHz and 2110 to 2170 MHz (UK)

2.5 GHz (US),3.5, 2.3/2.5, 5 GHz

5.9 GHz

licence licence-exempt licensed Licensed & licence-exempt

dedicated spectrum

access mechanism

contention-based centrally scheduled centrally scheduled contention based

limitations •Interference issues due to shared spectrum•short range

•high deployment costs •lower transmission rates, centralised.

•high deployment costs•centralised

short range

advantage •low deployment cost, •distributed

•already available,• high coverage

•high data rates•large coverage

•low deployment costs•Distributed

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10 802.11b at speeds II: speed dependence

Experiments performed under no-interference conditions (desert)

External antenna on the roof

UDP, TCP, HTTPObserved some

velocity-dependent packet loss

Gass, Scott, Dio, 2005.




WAVE CALM

Mobility


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1029 WAVE Scope

OBU

WA

VE

Sta

ck

Wire

line

Sta

ck

In Vehicle Network

OBU

WA

VE

Sta

ck

Wire

line

Sta

ck

In Vehicle Network

Applications

Optional External Interface Air Interface

WA

VE

Sta

ck

Applications

WA

VE

Sta

ck

Optional External Interface

Host

Wire

line

Sta

ck

Host

Wire

line

Sta

ck

Host

Wire

line

Sta

ck

Host

Wire

line

Sta

ck

Covered by WAVE StandardsROAD SIDE

UNIT

ON-BOARD UNITS

External Systems

External Systems

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1030 Protocol Architecture

UDP / TCP

LLC

PHY

WAVE MAC (including channel coordination)

Air

Inte

rface

IPv6WSMP

Data PlaneManagement Plane

Man

agem

ent

Sec

urity

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1031 Trial Use Standards

IEEE Std 1609.1-2006 Resource Manager

IEEE Std 1609.2-2006 Security Services

IEEE Std 1609.3-2007 Networking Services

IEEE Std 1609.4-2006 Multi-Channel

Operation IEEE P802.11p -

draft WAVE MAC and PHY

IEEE Std 802.11-1999 MAC and PHY

Lower Layers

Networking Services

Upper LayersWAVE Service Security

IEEE 1609.1, et al.

IEEE 1609.3

IEEE 1609.4, IEEE 802.11p

WAVE device

Medium

IEEE 1609.2

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1032 Full Use Standards in process

UDP / TCP

LLC

PHY

WAVE MAC (including channel coordination)

IPv6WSMP

1609

.3

1609.2M

anag

emen

t

Sec

urity

1609

.4

802.

11

Futu

re h

ighe

r la

yer s

tand

ards

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1033 Overview of 802.11p (D7.0)

Specifies channelization in the 5.9 GHz band Tunes some RF specs to allow highway operation Defines a mode of operation “outside the context of a

basic service set” Removes latency-causing link setup operations such as

authentication Defines a Time Advertisement message

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1034 Overview of 1609.4 Multi-Channel Operation

Extensions to the 802.11/802.11p MAC Management plane (MLME: MAC SubLayer Management

Entity) Manages optional regular switching between control channel and

service channel Queues regular time advertisements and/or service

advertisements Data plane (MAC)

Multiplexes/demultiplexes higher layer protocols (IPv6, WSMP) Queues messages for transmission on the correct channels Manages transmit message priority

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1035 1609 Channel Coordination examples

CCH

CCH

SCH

CCH Interval SCH IntervalCCH IntervalSCH Interval

Time

a)

b)

CCH

SCH

c)

CCH

SCH

d)

Continuous access

Alternating access

Immediate access

Extended access

Control Channel: management and (high priority) messages

Service Channel: general user message and IP traffic

For devices that don’t need continuous CCH access

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1036 1609.4 Transmit Operation

MAC (with Muti-Channel Operation)

Transmission Attempt

Channel Selector and Medium Contention

Internal Contention

AIFS[AC

] C

W[A

C]

TXO

P[AC

]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

Internal Contention

AIFS[AC

] C

W[A

C]

TXO

P[AC

]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

AIFS[AC

] C

W[A

C]

TXO

P[A

C]

CCH (WSM data only) SCH (WSM and/or IP data)

LLC

Channel Routing

802.

11p

MA

C (C

CH

)

802.

11p

MA

C (S

CH

)

Management frames

Management frames

AC=1 AC=2 AC=3 AC=4 AC=1 AC=2 AC=4AC=3

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1037 Overview of 1609.3 Networking Services

Management plane (WME: WAVE Management Entity) Generates contents of service advertisements based on higher

layer infoIncluding IP configuration info and security credentials

Monitors received service advertisements for services of interest to higher layers

Estimates channel quality Determines channel allocation/switching schedule to satisfy

service requests Data plane

Incorporates standard LLC and IPv6 Introduces thin WAVE Short Message Protocol (WSMP)

Allows direct control of RF parameters (e.g., power, data rate) by the higher layer

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1038 WAVE Short Message Protocol (WSMP)

Messages transmitted on request by higher layer Dest. MAC address, User Priority, Channel, Data rate, Transmit Power,

PSID Messages delivered over the air by MAC address

Unicast or broadcast Messages delivered up the stack by protocol and PSID

EtherType distinguishes WSMP from IP

WSM data

WSMP version PSID WSM

length

Higher layer

WSMP

LLC

MAC

WSM data

Control= 0x03

WSM dataWSMP HeaderEtherType

=0x88DCDSAP= 0xAA

SSAP= 0xAA

Channel number

Data rate

TxPwr_Level

PSID Length

PriorityDest_address

OUI=0x000000PriorityDest

address

Peer MAC

address

User priority

WME-Wave ShortMessage.req

DL-UNITDATA.req

MA-UNITDATA.req

SNAP headerLLC header

Data field

WSM element

ID

Ext. fields

Channel number

Data rate

TxPwr_Level

Channel number

Data rate

TxPwr_Level

Expiry Time

Expiry Time

Expiry Time

1 2311

1 21Var.4 Var.

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1039 “Services”

Provider role Sends out WAVE Service Advertisements (WSAs) on control

channelIncludes info on services and channelsMay include IP configuration infoIn Trial Use, included timing info – now separate

Operates on identified service channel(s) at designated times for application data exchange

User role Monitors WSAs for services of interest May visit identified service channels at designated times for

application data exchange Allocation of radio resources to communication channels

performed by 1609 stack based on higher layer request priority, service availability, device capabilities

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1040 WAVE Service Advertisement (WSA) contents

Channel InfoService Info

4 1 1 1 1 1

Channel Number

Adapt-able

Data Rate

TxPwr_Level

2 16 1 16 16

1

May be repeated

May be repeated

11

6

1Var.1

PSID Service Priority

Channel Number

Router lifetime IpPrefix Prefix

lengthDefault gateway

Primary DNS

Gateway MAC

address

Provider Service Table WAVE Routing Advertisement WAVE version

Extension fieldsRepeats

Extension fields

Extension fields

Var.

Var.

Extension fields

Var.

KEY

Optional Field

Lengths in octets

1

WAVE Element

ID

WAVE Element

ID

1

WAVE Element

ID

Info about available services Info about service channels

IP configuration info

Transmit Power Used

2D/3D Location

Advertiser Identifier

PSC

IPv6 Address

Service Port

Provider MAC Address

Secondary DNS

EDCA Parameter Set

KEY

Extension fields

Optional

Lengths in octets

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1041 Example of WAVE Transmit Protocol Layers

MLME

PHY Header

MAC Header

MAC Trailer

WSA

PHY

Security Header WaveService Advertisement Security

Trailer

WSA Header PST WRA

WME

Security Services

WME

Vendor Specific Action frame

Air interface

MAC

Vendor Specific Content

SEC-SignWSA.req

WME-ProviderService.req

SEC-SignWSA.cfm

MLMEX-WSA.req

Higher layer

Service info

MLME extension

WSAMLME-VSPECIFIC.reqOUI

Cont-ent

descr.

Category OUI

This illustrates content from the higher layers, processed by the WAVE stack, and sent out as a service advertisement in an 802.11 frame

IEEE 1609

IEEE 802.11

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1042 PSID & PSC

Provider Service Identifier (PSID) 4 octets; values allocated by IEEE Used as WSMP recipient address, and Used as primary identifier of services in WAVE Service

Advertisement Presumably identifies type of information and encoding to be

found on the SCH Provider Service Context (PSC)

0-32 octets; meaning determined by PSID Used as optional secondary service descriptor in WSA May indicate information sub-type, date tag, security context, etc.




WAVE CALM

Mobility


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1044 CALM - Overall

Continuous Air interface for Long and Medium distance

ISO TC204/WG16 – Wide Area Communications Support user transparent continuous communications CALM is the first open way to combine GPRS with

vehicle-optimized WLAN technology. NOT a complicated collection of new, unproven radio technologies

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1045 Services defined for 5 GHz medium - 1

Traffic Information - Audio Transfer - StreamingTraffic Information - Map UpdatesTraffic Information - Mobile InternetTraffic Information - Traffic DataTraffic Information - Traveller InformationTraffic Information - Vehicle Registration (EVI)Traffic Information - Transit Vehicle PriorityTraffic Information - Diagnostic Data TransferTraffic Information - Video Transfer - BlockTraffic Information - Audio Transfer - BlockTraffic Information - Video Transfer - StreamingTraffic Information - Repair Service RecordTraffic Information - Vehicle Software UpdatesVSC - OBU-to-OBU - Approaching Emergency Vehicle

WarningVSC - OBU-to-RSU - Emergency Vehicle Signal Pre-

emptionVSC - OBU-to-RSU - Intersection Emergency Vehicle

ApproachingVSC - RSU to OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Cooperative Collision Warning

CVO - Tractor-Trailer InterfaceCVO - Rollover WarningCVO - Electronic Border ClearanceCVO - Weigh Station Bypass ClearanceCVO - CVO Fleet ManagementCVO - Onboard Safety Data TransferCVO - Tractor-Trailer MatchingCVO - Transit Vehicle Data TransferCVO - Vehicle Safety InspectionCVO - Drivers Daily LogOTHER SERVICES - Probe Data CollectionOTHER SERVICES - Access ControlOTHER SERVICES – Vehicle Manufacturer InfoPAYMENTS - Toll CollectionPAYMENTS - ITS Service PaymentPAYMENTS - Other ePaymentsPAYMENTS - Rental Car ProcessingPAYMENTS - Parking PaymentPAYMENTS - Food PaymentPAYMENTS - Fuel PaymentSAFETY - Vehicle-to-vehicle Data TransferSAFETY – Highway-Rail Intersection Warning

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1046 Services defined for 5 GHz medium - 2

VSC - RSU to OBU - Map Downloads and UpdatesVSC - RSU to OBU - Enhanced Route Guidance and

NavigationVSC - RSU to OBU - GPS CorrectionsVSC - RSU to OBU - Adaptive Headlight AimingVSC - RSU to OBU - Adaptive Drivetrain

ManagementVSC - RSU to OBU - Merge AssistantVSC - RSU to OBU - Sign Information (warning

assistance)VSC - RSU to OBU - Point-of-Interest NotificationVSC - RSU to OBU - Curve Speed WarningVSC - RSU to OBU - Highway/Rail Collision WarningVSC - RSU to OBU - Animal Crossing Zone

InformationVSC - RSU to OBU - Low Bridge WarningVSC - RSU to OBU - Work Zone WarningVSC - RSU to OBU - Stop Sign WarningVSC - RSU to OBU - Keep Clear' WarningVSC - RSU to OBU - Wrong-way Driver WarningVSC - RSU to OBU - Left Turn AssistantVSC - RSU to OBU - Infrastructure Intersection

Collision WarningVSC - RSU to OBU - Pedestrian Crossing InformationVSC - RSU to OBU - Pedestrian/Children WarningVSC - RSU to OBU - School Zone WarningVSC - RSU to OBU - Stop Sign Movement AssistanceVSC - RSU to OBU - Traffic Signal WarningVSC - RSU to OBU - Low Parking Structure Warning

VSC - OBU-to-OBU - Pre-crash SensingVSC - OBU-to-OBU - Intersection Collision WarningVSC - OBU-to-OBU - Enhanced Differential GPS

CorrectionsVSC - OBU-to-OBU - Highway/Rail Collision WarningVSC - OBU-to-OBU - Vehicle-based Road Condition

WarningVSC - OBU-to-OBU - Road Feature NotificationVSC - OBU-to-OBU - Curve Speed WarningVSC - OBU-to-OBU - Visibility EnhancerVSC - OBU-to-OBU - Electronic Brake LightsVSC - OBU-to-OBU - Hybrid Intersection Collision

WarningVSC - OBU-to-OBU - Instant (Problem) MessagingVSC - OBU-to-OBU - Blind Merge WarningVSC - OBU-to-OBU - Post-Crash WarningVSC - OBU-to-OBU - Merge AssistantVSC - OBU-to-OBU - Lane Change AssistantVSC - OBU-to-OBU - Left Turn AssistantVSC - OBU-to-OBU - Stop Sign Movement AssistantVSC - OBU-to-OBU - Cooperative Glare ReductionVSC - OBU-to-OBU - Blind Spot WarningVSC - OBU-to-OBU - PlatooningVSC - OBU-to-OBU - Cooperative Adaptive Cruise

ControlVSC - OBU-to-RSU - Infrastructure-based Traffic

ProbesVSC - OBU-to-RSU - SOS ServicesVSC - OBU-to-RSU - Post-Crash WarningVSC - OBU-to-RSU - Just-in-Time Repair NotificationVSC - OBU-to-RSU - Intelligent On-ramp MeteringVSC - OBU-to-RSU - Intelligent Traffic LightsVSC - OBU-to-RSU - Blind Merge Warning

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1047 CALM classic architecture

ISO TC204 ITS APPLICATIONS

IPv6 layer

TCP UDP

ServiceQoS

Interface Selection

Handover

InterfaceQoS

Stream &RealtimeProtocols

ISODSRC

L7

HTTP/SMTP

Protocols

MAC

802.11pWAVE

InitHnd-ovr

Secur

MAC

2G/3GGSM

InitHnd-ovr

Secur

MAC

GPS/Galileo

InitHnd-ovr

Secur

L2/UDP

…

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1048

IMEInterface Manager

ISO 24102

NMENetworkManager

ISO 21210

CMECALM

Manager

ISO 21210

NETWORK INTERFACERouting and Media Switching based on IPv6

ISO 21210

Non-CALM-awareISO 15628-basedAPPLICATIONS

Convergence LayerPart of ISO 15628

ISO 21210

CALM-AwareAPPLICATIONS

TCP/UDP/…INTERNET

STANDARDSSAP

SAP SAP

SAP

SAP

SAP

SAP

Non-CALM-awareIP (Internet)

APPLICATIONS

Convergence LayerIP socket/ISO 21210

SAPSAP

SAP

CALM Media External Media

CALM System Architecture (21217) (Rev. Geneva)

ApplicationManagementISO 24101

…

GPR

S

ED

GE

2G CellManager

ISO 21212ISO 21218

SAP

CALM Network 21218 = LSAP

SAP

Applications

SAP

…

cdma2k

UM

TS

3G CellManager

ISO 21213ISO 21218

SAP

… IR-B

IR-A

ISO 21214IR

Manager

ISO 21218

… WiFi

M5

ISO 21215W-LAN

Manager

SAP

ISO 21218R

AD

AR

MM

-J

MM

-E

ISO 21216MillimeterManager

SAP

ISO 21218

K-D

SRC

J-DSR

C

C-D

SRC

DSRC ISO15628

ISO 24103

SAP

ISO 21218

…

HC

-SDM

A

WiM

AX

ISO 24xxxW-MAN

Manager

SAP

ISO 21218

… DA

B

GPS

ISO 24xxxBroadcastManager

SAP

ISO 21218

…

W-U

SB

BlueT

ISO 24xxxPAN

Manager

SAP

ISO 21218

Ether

AM

IC

CA

N

ISO 24xxxWired

Manager

SAP

ISO 21218

SAPSAPSAP

CME

Registration ofIngress/Egress

InterfacesSAP

SAP SAPData SAP Management SAP

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1049 Vehicle Architecture

In-Vehicle App

Sensors, HMI and Control

ITS In-Vehicle Network 100baseT EthernetIn-vehicle OEM networks CAN/VAN/MOST/AMI-C..

IVN DLL

IVN PHY

Combined Antenna Pod

Network

Ethernet

Ethernet

CVIS Integrated Mobile Router

CALM M5 PHY

CALM MAC

CALM LLC

Network

CME.Router

IME.Router

NME.Router

DSRC L1

DSRC L2/L7

DSRCConvergence

Network

GPS PHY

GPS Stack

GPSConvergence

Network

Blue-toothBlue-tooth

Commsgateway

Nomadic device Gateway

C2C-CCFast Net

OEM G/W

Fire

wal

l

Ethernet

Ethernet

IVN DLL

IVN PHY

CALMNetwork

Layer

C2CSwitchLayer

RTLink

Real-timeApplications

Real-timeApplications

GPRS PHY

GPRS Stack

GPRSConvergence

Network

Refpt

CALM Routing

CALM Manager

FOAMHMI Security VehicleAPI Mntg Agent

COMMSserver

Operating System and Hardware CALM

CVIS RTapps

COMOserver

POMAMapping server

(native) J VM

Runtimeenvironment(OSGi)

CVISapp1

CVISapp2

CVISapp3

COMO ProbeData app

POMAclientapp

Apps

Services &Middleware

PlatformCore

Functions

CALM Manager

FOAMHMI Security VehicleAPI Mntg Agent

COMMSserver

Operating System and Hardware CALMCALM

CVIS RTapps

COMOserver

POMAMapping server

(native) J VM

Runtimeenvironment(OSGi)

CVISapp1

CVISapp2

CVISapp3

COMO ProbeData app

POMAclientapp

Apps

Services &Middleware

PlatformCore

Functions

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1050 Communication Scenarios

CALM defines 5 communication scenarios:

0 – V2I Non-IPv6 (WSMP or C2C-CC?)

1 – V2I/V2V Local IPv6 2 – V2I MIPv6 3 – V2I NEMO 4 – V2V Non-IPv6

(WSMP or C2C-CC?)Internet

Access Router

Mobile Router

LFN LFN LFN

CNHA

Internet

Access Router

Mobile Router

LFN LFN LFN

Mobile Router

LFN LFN LFN

CNHA

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1051 What is CALM M5? US DSRC (WAVE)

WAVE is IEEE 802.11p, as required by US DoT/VSCC/VII/… WAVE is optimised for US channel plan WAVE protocols are optimised for current single-radio technology. No GSM or other technology is included.

CALM M5 incorporate WAVE and adds: Global (European) 5 GHz spectrum Regulatory domain (border) management Directivity and EMC control CEN DSRC co-operation Multiple radio/interface/antenna management GPRS/UMTS network interconnectivity

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1052 CALM M5: C2C-CC & WAVE

Geoaddressed applications

(e.g. active safety)

IPv6

TCP / UDP

IP Applications (Deployment)

C2C-CC Network Layer

PHY (IEEE 802.11p)

LLC/MAC (IEEE 802.11p)

B

A C

WSMP

B

C2C MAC P1609.4

WAVE Short Message Apps




WAVE CALM

Mobility


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1054 Mobility

Mobility is the key issues in Vehicular Networks In cellular based networks, handoff is a mature technique

Handoff in GSM networks Handoff in CDMA networks

In IP based networks, handoff is immature WiMax, Wi-Fi

Vertical handoff, NEMO are being pursued…

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1055 Different Types of Mobility

Scale Pico Micro Macro Global

Network Vertical Handoff Horizontal Handoff

Moving Entity Host mobility User Mobility Application Mobility Network Mobility

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1056 How to handle Mobility?

Where can we address this problem? Physical layer? (sure; very limited) Link layer Network layer Transport layer “Something higher” (often called session) Application layer

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1057 How to handle Mobility?

Where can we address this problem? Physical layer? (sure; very limited) Link layer Network layer Transport layer “Something higher” (often called session) Application layer

Possible to code many applications to deal with disconnection It’s all about trying to resume and managing stateBut should the burden be placed on every application

developer?

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1058 Link-layer mobility

What timescales does it support? Pretty durned fast

Have the link layer mask mobility E.g., the campus 802.11 wireless. You can move anywhere and

keep the same MAC and IP addressCompletely transparent. No OS/App support needed. Brilliant!Fast & Local: Only switches near moving client must be

updated.But – only local! Can’t move out of your subnet.

How about different links, different technologies? IEEE 802.21

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1059 IP Layer Mobility

Allow hosts to take their “home” IP address with them wherever they go.

Advantages: Potentially global mobility scope (not limited to subnet like link

layer) Transparent to applications and layers above IP

How can we do it?

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1060 Brute Force: IP routing

If node leaves home, send out (global?) routing announcement pointing to new location In theory, “just works” Example: Boeing’s “Connexion” announced a /24 into BGP for

every supported airplane and moved the announcement to the gateway the plane was closest to

Why? Latency concerns over really long flights (start in SF, end in London)

Already have high latency from using satellites. But wouldn’t scale for single IP addresses

Every AS in world would have routing entry for every mobile user in the world? Ouch!

Problem: Having the whole world maintain state for every user

Alternative: Keep state local, by…

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1061 Mobile IP (& others):

Same as other problems in Computer Science Add a level of indirection

Keep some part of the network informed about current location Need technique to route packets through this location

(interception) Need to forward packets from this location to mobile host

(delivery)

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1062 Mobile IP

RFC 3220 “IP Mobility Support for IPv4”, C. Perkins, Ed., Nokia Research Center, January 2002

has many features: home agents, foreign agents, foreign-agent registration, care-of-

addresses, encapsulation (packet-within-a-packet) three components to standard:

indirect routing of datagrams agent discovery registration with home agent

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1063 IP Mobility: Principles

Core network routing transparency Routers and switches are un-aware of mobility

Host-controlled location update to effect routing path change Responsibility rests on the Mobile Node (MN)

Adheres to the “end-to-end” model Minimal network support Intelligent host

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1064 Solution Requirements

Roaming: Roaming: Packets need to reach the current location of a Mobile

Node Handover:

Connection (session) end-point must remain constant even though the IP address changes

Connection end-point must be able to handle change of IP address

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1065 Mobile IP: indirect routing

Permanent address: 128.119.40.186

Care-of address: 79.129.13.2dest: 128.119.40.186

packet sent by correspondent

dest: 79.129.13.2 dest: 128.119.40.186

packet sent by home agent to foreign agent: a packet within a packet

dest: 128.119.40.186

foreign-agent-to-mobile packet

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10 Mobile IP: agent discovery66

agent advertisement: foreign/home agents advertise service by broadcasting ICMP messages (typefield = 9)

RBHFMGV bits reserved

type = 16

type = 9 code = 0 = 9

checksum = 9

router address standard

ICMP fields

mobility agent advertisement

extension

length sequence #

registration lifetime

0 or more care-of-addresses

0 8 16 24

R bit: registration required

H,F bits: home and/or foreign agent

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10 Mobile IP: registration example67

visited network: 79.129.13/ 24 home agent

HA: 128.119.40.7 f oreign agent

COA: 79.129.13.2 COA: 79.129.13.2

….

I CMP agent adv. Mobile agent MA: 128.119.40.186

registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification:714 ….

registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification: 714 encapsulation format ….

registration reply HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 encapsulation format ….

registration reply HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 ….

time

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1068 Mobile IP Issues

Route Optimization In order to always use HoA, packets need to be routed through the

Home Agent introduces sub-optimal routing and hence potentially longer delay Direct communication between the MN and its correspondents

should be possible Authentication

Registration messages Binding cache updates

Must send updates across network Handoffs can be slow

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1069 Mobile IP Optimization

Fast Handoff Handoff delay is too long Can we reduce it? FMIP, FMIPv6

Hierarchical Handoff Frequent Binding Update incurs burden on Let’s handle the local movements inside the local network

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1070 Handoff Delay Illustration

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1071 Fast Handover Protocol

Allows a MN to learn new Router information when still attached to the current router enables fast movement detection expedites new address configuration facilitates immediate transmission upon new link establishment

Allows a MN to receive packets sent to its previous IP address until Binding Update to Home Agent is completed Binding Update to the correspondent is completed

Involves tunnel establishment triggered by MN signaling

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10 Fast Handover Illustration72

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1073 Delays with Fast Handover

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1074 Hierarchical MIP:

Macro Mobility and Micro Mobility Macro Mobility

Domain-level, Mobile IP-based Micro Mobility

Cell area, Hierarchical MIP

Home Agent

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1075 Transport-layer solution

TCP Migrate Idea: No IP support; just have transport layer

dynamically re-bind endpoints MIGRATE

DNS Server

Mobile Hostfoo.bar.edu

Location Query(DNS Lookup)

Connection Initiation

Location Update(Dynamic DNS Update)

Connection Migration

xxx.xxx.xxx.xxxyyy.yyy.yyy.yyy

CorrespondentHost

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1076 Migrate

Advantages: (Mostly) transparent to applications

Unless they know their IP address and use it, e.g., peer-to-peer apps.

Keeps state and modifications entirely at endpoints No triangle routing! All communication is direct

But: Requires TCP support / only works for TCP

Not true in general: “Host ID Protocol” – HIP – can work with both, but requires more invasive IP stack changes

Slower timescales than link-layer migration (several RTTs)

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10

77

Other issues: Network Mobility (NEMO) Support

The vehicle changes its point of attachment to the Internet Host Mobility

Each node maintains Internet access

Each host must perform Mobile IPv6

Network Mobility Only the mobile

router(MR) maintains Internet access

Nodes can be located behind the MR

Host Mobility Support

Mobile Router

Network Mobility Support

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1078 Other issues: Host Identity Protocol (HIP)

Considerable recent work: Give each host a unique identity Simplifies mobility Also simplifies multi-homing! (Many related issues) Deployment Issue

Idea: IP address: changes with location HIP does not change

Application-specific identifiers

Pairs <IP address, Port#> +Transport Protocol ID

Data Link Layer

Network Layer

Transport Layer

Application Layer

Host IdentityHost Identity (HI)

IP addresses

Link layer addresses

Redes Inalámbricas – Tema 5 Vehicular Networking

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Transcript of Redes Inalámbricas – Tema 5 Vehicular Networking