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Vehicular Communications(Ubiquitous Networks for

Sustainable Mobility)

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Introduction

V2V/V2I Communication-based Automotive Applications

V2V/V2I Application Characterization and Classification

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What is a VANET ?Vehicular Ad-hoc

Networks

Individual nodes different from traditional wireless nodes

No power constraint

Nodes mostly mobile

Extends existing infrastructure

Vehicle-Vehicle

Communication

Vehicle-

Infrastructure

Communication

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F o r w a r d r a d a r

C o m p u t i n g p l a t f o r m

E v e n t d a t a r e c o r d e r ( E D R )

P o s i t i o n i n g s y s t e m

R e a r r a d a r

C o m m u n i c a t i o n f a c i l i t y

D i s p l a y

(GPS)

- Human-Machine Interface

- Navigation system

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• Processing power: comparable with a Personal Computer + a

few dozens of specialized processors

• Communication: typically over a dedicated channel:

Dedicated Short Range Communications (DSRC)

• In the US, 75 MHz at 5.9 GHz;

• In Europe, 20 MHz requested but not yet allocated)

• Envisioned protocol: IEEE 802.11p

• Penetration will be progressive (over 2 decades or so)

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V2V/V2I Communication-based Automotive Applications

From an application benefit viewpoint, V2V/V2I applications can be classified as Safety Applications Convenience Applications Commercial Applications

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Safe

ty

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among those listed, safety-oriented applications are of special interest because they are expected to significantly reduce the fatalities and economic losses caused by traffic accidents

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Con

ven

ien

ce

Com

merc

ial

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Safety applications

SVA (Stopped or Slow Vehicle Advisor)

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PCN: V2V Post Crash Notification

EEBL: Emergency Electronic Brake Light

RHCN: Road Hazard Condition Notification

RFN: Road Feature Notification

CCW: Cooperative Collision Warning

CVW: Cooperative Violation Warning

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Convenance Applications

CRN (Congested Road Notification)

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TP: Traffic Probe

TOLL: Free Flow Tolling

PAN: Parking Availability Notification

PSL: Parking Spot Locator

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Commercial Applications RVP/D: Remote Vehicle

Personalization/Diagnostics

SA: Service Announcements

CMDD: Content, Map or Database Download

RTVR: Real-Time Video Relay

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V2V/V2I Application Characterization and ClassificationApplication Characteristics

describe properties directly related to the applications themselves

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Classification Criteria: Network Attributes

Networking Attributes characterize the fundamental aspects of network design for

communication-based automotive applications

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Application Characteristic Characterization

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Applications exhibit commonalities!

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Network Attribute Characterization

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Application Classification (1)

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Networking Attributes Perspective

1. Safety

- SVA, EEBL, PCN, RHCN, RFN, CCW, CVW

2. Convenience

- CRN, TP, TOLL, PAN, PSL

3. Commercial

- RVP/D, SA, GMDD, RTVR

Application Benefit Perspective

Short Message Communications Content Download/Steaming

Broadcast Unicast

File Download

Video Streaming

Event-driven

Periodic On-demand Financial Non

Financial

Unicast

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Application Classification (2)Group applications into 7 generic classes:

Accommodate the applications of interest

Class Name Representative Applications

1 Event-Driven Short-Message Broadcast SVA, EEBL, PCN, RHCN, and RCN

2 Scheduled (Periodic) Short-Message Broadcast

CCW ( Cooperative Collision Warning), CVW (Cooperative Violation Warning)

3 On-Demand Short-Message Broadcast SA (Service Announcements)

4 Financial Transaction Short-Message Unicast

RVP/D (Remote Vehicle Personalization/Diag) TOLL (Free Flow Tolling)

5 Non-Financial Transaction Short-Message Unicast

TP, PAN, PSL

6 File Download CMDD (Contents, Map or Database Download)

7 Video Streaming RTVR (Real-Time Video Relay)

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- Only (7 generic classes) application models- Individual applications are simple extensions from the generic models

SVA: Stopped or Slow Vehicle AdvisorEEBL: Emergency Electronic Brake LightPCN: V2V Post Crash NotificationRHCN: Road Hazard Condition NotificationRFN: Road Feature Notification

TP: Traffic ProbePAN: Parking Availability NotificationPSL: Parking Spot Locator

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Performance Metrics for Communication-based Automotive Applications

We mainly concentrate on safety applications, since they are the initial focus of automotive industry

Necessity to introduce novel application-level metrics to accurately capture performance trends of safety applications

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Level Metric Description Classes

Network Packet Delivery Ratio packets received / packets transmitted 1, 2, 3, 4, 5, 6

Network Per-Packet Latency packet reception time – packet transmission time

1, 2, 3, 4, 5

Application T-window Reliability prob. of receiving at least one transmitted packet within a given time interval

1, 2, 3

Application Time-to-Successful Reception

application-level packet reception latency 1, 2, 3

Application QoS Metrics end-to-end packet delay, jitter, and throughput 7

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ADVANTAGES

 Reducing the likelihood of collision at

intersections.

Reducing the likelihood of road departure crashes.

Providing more accurate and timely road condition alerts.

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DISADVANTAGES

The whole system cannot be work without network connectivity

This process can be done if and only if every vehicle should active their communication system

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APPLICATIONS

Using V2V communication, when a vehicle on the road acts abnormally, e.g., deceleration exceeding a certain threshold, dramatic change of moving direction, major mechanical failure, etc., it becomes an abnormal vehicle (AV). An AV actively generates Emergency Warning Messages (EWMs), which include the geographical location, speed, acceleration and moving direction of the AV, to warn other surrounding vehicles. A receiver of the warning messages can then determine the relevancy to the emergency based on the relative motion between the AV and itself.

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FUTURE SCOPE

The authors are currently investigating efficient communication mechanisms to disseminate CoTEC’s road traffic congestion information to vehicles approaching the congested area.

Using this information, vehicles would be able to modify their route, and select alternative ones that avoid the congested area.

An interesting research area would then be to investigate how to efficiently couple V2V-based road traffic monitoring mechanisms with cooperative traffic management strategies.

Such coupling should be studied in large scale scenarios in order to better understand the impact on road traffic conditions, and the capability of cooperative systems to efficiently distribute road traffic flows. 

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CONCLUSION Cooperative vehicular communications open

new possibilities to develop advanced traffic monitoring solutions in next-generation ITS systems.

In this context, this paper has presented CoTEC, a novel distributed technique using V2V communications to detect and characterize traffic congestion.

The proposed technique includes mechanisms to compensate the impact of radio propagation on the accurate estimation of traffic density, and to account for the gradual market introduction of cooperative vehicular communications.

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THANK YOU

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