Insert Title Here

Innovative Data Collection and Dissemination in V2X Networks

Wassim Drira, Fethi Filali

04/18/23

Connected vehicles and road safety

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Context & Problem Statement

MasarakTM Traffic

Information

Platform

MasarakTM Traffic

Information

PlatformMobilit

y Analyt

ics

Mobility

Analytics

Traffic Analytic

s

Traffic Analytic

s

Crowd sourced data

Crowd sourced data

Road Sensor (WaveTraf)

Road Sensor (WaveTraf)

GPS devicesGPS devices

Multiple Data

Sources

Delivery:Web

MobileSMSVoice

FM

Delivery:Web

MobileSMSVoice

FM

DATA COLLECTION + MANAGEMENT + ANALYTICS

Intelligent Transportation Systems (ITS)

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Data collection & dissemination in V2X

OBU RSU TMC MSP

• OBU: On-Board Unit• RSU : Road Side Unit• TMC : Traffic Management Center• MSP : Mobility Service Provider

IEEE802.11p ADSL, Fiber, etc.

3G/LTE

Data CollectionData Collection

Data DisseminationData Dissemination

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Named Data Netorking (NDN)• NDN (Named Data networking) (http://named-data.net) is a future Internet

architecture based on:– Treats content as a primitive – decoupling location from identity, security and access,

and retrieving content by name.– Replace the where with what in the network.– It can run alone or on top of IP stack.– Hierarchical names– Request/Response – three main data structures:

• the FIB (Forwarding Information Base), • Content Store (buffer memory) • and PIT (Pending Interest Table)

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Named Data Netorking (NDN)

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NDN-Query: Motivations• Need to collect and analyze traffic information in order

to:– Understand the traffic status – Detect incidents– Etc.

• The obvious solution is to collect the periodic beacons from the vehicular network through Road Side Units (RSU) in a centralized Traffic Management Center (TMC).

• But, this solution generate a tremendous amount of data to be transmitted to TMC and then processed.

– ~ 114GB per day and per RSU The idea is to filter and aggregate the collected data on the fly.

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NDN-Query: Naming Pattern

OBU RSU TMC MSP

query

response

+ Data is collected from one or many node.+ Data is built on the fly and hop by hop.+ Fully distributed query mechanism + Data aggregation hop by hop

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NDN-Query: Step by Step example

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Publish/Subscribe extension to NDN: Why?• Use of multicast and caching.• Decouple publishers and subscribers.• Push enabled dissemination.• Scalability: it is able to handle large number of publishers and subscribers and

large amount of information to disseminate.• Efficiency: content is not transmitted multiple times by a server or on a link. • Subscriber offline and mobility support. • Does not distinguish between transient or persistent data.• Tagging publications with version, generation time and freshness (new or

resubmitted).

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Pub/Sub : Network Model• OBU : can act as subscriber, publisher or Local Rendezvous Node (L-RN).• RSU : can act as subscriber, publisher or L-RN.• TMC : hosts the Pub/Sub broker having local and Global Rendezvous

Nodes (G-RN), powerful servers, NDN routers and Back-up nodes.o L-RN : Local-Rendezvous node receives events from nodes in layer one or

two o G-RN : Global-Rendezvous node receives events from nodes in layer two or

three.o BNs: Back-up Nodes are subscribed to all the content descriptors in order to

store all the publications and be able to provide this content to disconnected subscribers when needed.OBU RSU TMC MSP

• OBU: On-Board Unit• RSU : Road Side Unit• TMC : Traffic Management Center• MSP : Mobility Service Provider

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Pub/Sub : Content Identification• Content Identification

– Content Name– Content Descriptor (CD)

• /traffic/qatar/doha/accidents, /traffic/qatar/doha/jams, /traffic/qatar

• Location• Time : Time Stamp, Version , Validity Time (Pub: finite or infinite VT,

Sub: infinite, finite, or associated to a unique publication)• Data Tables

– Subscription Table (ST): stores subscriptions, number of subscribers, In/Out interfaces, cache of recent publications and timers in RNs and on-route nodes.

– Publish-Forwarding-Table (PFT): On receiving a Publish message, only non-existing messages in the PFT are forwarded and stored for a time T (the round trip delay) in the same table.

– Updates to CS: store publish messages and validity timers to allow on-route caching and the automatic removing of expired messages.

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Pub/Sub : Subscribe & Publish processing

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Pub/Sub : What’s more?

• The extension allow disconnected nodes to get published messages during this period when they return.

• Pub/Sub supports subscribers mobility

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Simulation SetupNDN-Q parameters

Publish/Subscribe parameters:•VT=10s •Publish VT=infinite•T2=2s.

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Simulation results : NDN-Q

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Simulation results : Pub/Sub data dissemination

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Simulation results : Pub/Sub data collection

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Conclusions• We presented NDN-Q:

– A fully distributed query mechanism that does not require knowledge of the network organization and vehicles position.

– A new query naming pattern and aggregation scripts.– The query response in NDN-Q is built on the fly and hop by hop.– The evaluation argues that this extension reduces the number of packets collected from data

sources, efficiently handles the mobility of vehicles, and deliver query results in a reasonable time (280ms).

• The Pub/Sub extension to NDN provides an Efficient Data Collection and Dissemination in V2X Networks.

• More information about our works in the NPRP project CoSMob can be foun inwww.cosmob.or

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