1 Prof. Chung-Ming Huang Introduction to Telematics and ITS research topics National Cheng Kung University Department of Computer Science and Information

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Prof. Chung-Ming Huang

Introduction to Telematics and ITS research topics

National Cheng Kung UniversityDepartment of Computer Science and Information Engineering

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OutlineOutlineIntroduction of Telematics

ConceptApplication and Service CasesTowards the Future

Technical Issue of TelematicsDSRC, a Technical ReviewStandardization for DSRCIndustrial and Academia

Research Issues of TelematicsFundamental Research Topics in TelematicsTechniques Development

Current Results

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MotivationMotivationIncreasing demand for network access

from vehiclesE.g., Web, email, VoIP…

Newly rising demand for cyber physical applications in ITSE.g., Computer Aided driving, safety

system, GIS… Ubiquity of radio coverage

Cellular(2G, 3G, B3G), WiFi, WiMax, …More smart objects embedded (RFID,

Sensors…)Usability of GPS and Satellite

communication

Summary• Telematics have much richer meanings

other than traditional telecommunication using mobile phone.

• ITS have brought fresh blood as well as new demand to telematics.

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EtymologyEtymology

Determined by Automotive Telematics author and academic Dennis Foy

TeleTele From the Greek Tele"

~Matics~Matics ~Matos, a derivative of the Gk machinari, or contrivance

'far away', especially in relation to the process of producing or recording)

usually taken in this context to mean 'of its own accord'

TelematicsTelematicsDescribing the process of long-distance transmission of computer-based information.

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TelematicsTelematicsTelematics is the term given to the technology that enables

remote access to vehicle data over a wireless network.

Telematics is used for the collection and dissemination of information between vehicle-based electronic systems, for vehicle tracking and positioning, on-line vehicle navigation, information systems and emergency assistance

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ConceptConcept

The term telematics (synonymous with telemetry) is used in a number of ways: The integrated use of telecommunications and informatics, also known as ICT

(Information and Communications Technology). More specifically it is the science of sending, receiving and storing information via telecommunication devices.

More recently, telematics have been applied specifically to the use of Global Positioning System technology integrated with computers and mobile communications technology in automotive navigation systems.

Most narrowly, the term has evolved to refer to the use of such systems within road vehicles, in which case the term vehicular telematics may be used.

It is a specialist technology which harnesses the power of telemetry (data collected via GPS and communicated via the GSM network?) combined with informatics (interpretation, management and distribution of information).

It provides fleet and vehicle asset managers with effective solutions for the efficient management of their mobile transportation assets, through the integration of cellular, geo-positioning, internet and software technologies

From wikipedia

From OnStar

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Other Versions of Telematics DefinitionOther Versions of Telematics Definition

A definition of a telematics system [Vissers]:A Telematics System supports interactions over distance

and/or time between people and/or processes by means of the integrated application of telecommunication and information technology.

Telematics Systems are used in:personal communication (telephone, e-mail, video

conferencing)banking, broking, insurancedistance learning, cooperative workingdesign and manufacturing (CAD/CAM), office automation

Summary:• There are many versions of Telematics concept.• There is no authoritative definition.• But we can summarize the features in:

• What is needed by Telematics?• What Telematics can supply us?

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FeaturesFeatures Telematics belong to:

Communication system Telematics should have:

Rich Communication Infrastructures GPS navigation supports Traditional Communication system supports

Cellular Comm. System, e.g., GSM, UMTS Internet Access, e.g., Mobile IP Wireless Access, e.g., WLAN, WAVE (802.11p), Mesh Intelligent Transportation system (ITS), e.g., driving assistance, safety comm. Vehicular Ad Hoc Network, V2V Comm.

Telematics Architecture: All are covered under the Telematics umbrella

Telematics supply: Network Access for Vehicle User, including Telecomm. Net. and Internet Fleet and vehicle asset managers Various of services, e.g., location services, ITS Service, More Innovative applications, … …

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More specific for Vehicular TelematicsMore specific for Vehicular TelematicsUsed to define connected vehicles interchanging electronic dataThese systems may be used for a number of purposes:

Collecting road tollsManaging road usage (intelligent transportation systems)Pricing auto insuranceTracking fleet vehicle locations (fleet telematics)Cold store logisticsRecovering stolen vehiclesProviding automatic collision notificationLocation-driven driver information servicesRemote diagnosticsforthcoming applications including on-demand navigation, audio and

audio-visual entertainment contentTechnologies particularly used:

Dedicated Short Range Communications (DSRC)

Summary• While there are many potential applications for vehicular

Telematics, the main advantage for transportation safety advocates is that it will help reduce and ideally eliminateroad injuries and road traffic related deaths worldwide.

• Services that connect the car to outside data are expected to proliferate in vehicles coming onto future market.

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Telematics Services Cases (1)Telematics Services Cases (1)

Standard equipment of “Help Net”, an emergency reporting device The standard equipment of “Help Net” is used in cases on

accident or sudden illness, whereby one can be connected to an exclusive operator at the touch of a button and request an ambulance by speaking into the microphone of the onboard unit.

Car audio system with a built-in G-DRM (G-Digital Rights Management) for music distribution On-demand car audio “G-DRM”, a digital protection system for

copyrighted works that manages encrypted music data stored on a hard disk.

Dedicated communication device: “DCM for exclusive use with GBOOK ALPHA”

G-BOOK ALPHA ⇒ ToyotaG-LINK

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CARWINGS ⇒ NISSAN

Operator Service The driver can contact an operator by phone around the clock via a switch and

communicate his/her requests. Voice communication with an operator enables the driver to know the settings of the destination for the satellite navigation system, traffic information. Also, the driver can be interconnected to road services to obtain information on the closest hospitals.

To provides Information on Gasoline Prices Based on the location of a moving vehicle, real-time information of the

market price of gasoline in neighboring regions, and sales prices at recommended gas stations are displayed on a monitor.

(Others –under experimentation) Info-communications system utilizing

road-to-vehicle communications technology for the purpose of reducing collisions at intersections

Information provision system regarding speeding alerts driver to slow down speed in a School Zone, etc.

Dynamic route guidance system utilizing probe data to alleviate congestion and provide the fastest route

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Floating Car System When a member’s car is operated in a preset road zone, the time

required to drive through the zone is uploaded for the supply of information. In addition, data provision by using satellite images is implemented.

Congestion Forecast Information Based on cumulative past data on congestion, changes in road conditions are

projected with high accuracy. Taking into account the time required for the vehicle to drive through the area, the least congested route is shown.

Lane-specific information Route guidance is provided taking into consideration the land-specific flow as well.

Inter-navigation Weather Weather information that will impact

driving is provided. Increased Operation Efficiency via

Exclusive Communication Cards

InterNAVI Premium Club ⇒ Honda

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Collection and Analysis of Vehicle Operational information Operational data (fuel consumption, emissions volume of CO2, Nox, PM, location data,

driving operational data for the driver) are provided in real time. Vehicle Emergency Tracking Service

A service of ongoing reports on the location of the vehicle in case of emergency, such as car theft.

Temperature notice service A service to notify the person in charge when the temperature of the truck bed deviates from

the preset temperature range

Mimamori-kun (vehicle diagnostic information) ⇒ Isuzu

Higher speed and more advanced-function onboard communication modules together with expanded and improved network service environments, etc. are expected to enhance the environment, realizing even faster mobile communications. As a result, an even newer and more convenient Telematics industry will be created.

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Market of TelematicsMarket of Telematics

Resource; IEK (2008/10)

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Major Project of TelematicsMajor Project of Telematics

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Project of VII (North America)Project of VII (North America)

Vehicle Infrastructure Integration (VII)主要由 GM 、 Toyota 、 Ford 、 Daimler

Chrysler 、 Honda 、 BMW 、 Nissan 、 Volkswagen 等8 家車廠共同合作開發

以 DSRC 為實體通訊層面的關鍵技術。VII 為 U.S Department of Transportation 所訂定，主要的訴求為於改善交通安全與疏導交通等問題，其基本的定義就為一建立在車間以及車對道路之通訊，透過DSRC （ Dedicated Short Range Communications ）通訊技術在 5.9GHz 頻帶上進行無線通訊傳輸。

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Project of GST (Europe)Project of GST (Europe)

由 50 多家業者在歐洲共同合作推展 Global System for Telematics (GST) 計畫

主要的目的在於協助歐盟走向共通開放相之車載資通訊服務市場。

此計畫由歐盟委員會指導，並由英、法、德、義、瑞等共 50 多家業者協同合作，在七個主要城市進行Field Test 的大型車載資通訊標準技術開發與實驗。

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Project of VICS (Japan)Project of VICS (Japan)

由 Toyota 、 Nissan 、及 Honda 參與的 Vehicle Information & Communications System (VICS) 計畫

各車廠分別以 VICS 系統發展自有品牌的車載資通訊服務

分別為： G-Book Alpha (Toyota) 、 Carwings (Nissan)及 Internavi (Honda) 。

雖然 Honda 進入 Telematics 發展的時間較晚，但Internavi 的會員人數於 2007 年已突破 50 萬人，多於G-Book Alpha 及 Carwings 。

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Telematics MarketTelematics Market

Global Market

Market Estimation of Telematics

Market of Cars in China

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Global MarketGlobal Market

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Global Market (Cont.)Global Market (Cont.)

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Market Estimation of TelematicsMarket Estimation of Telematics

Source: IBTS

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Car Market in ChinaCar Market in China

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Telematics IndustryTelematics Industry

Telematics service contains content information, terminal device, communication infrastructure.

Telematics Industry contains automotive industry, information industry, electronics industry, communication industry, digital content industry etc.

It must integrate with differ industries of above for providing services.

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International Telematics DevelopmentInternational Telematics Development

Focus Standard or Project

AmericaFocus on generality telematics system of customer.

AMI-C (Automotive Multimedia Interface Collaboration)

MOST (Media Oriented System Transport)OSGi Alliance

EuropeFocus on commercial vehicles application.

COMETA (COMercial vehicle Electronic and Telematic Architecture), KAREN, FLEETMAP, CEN TC278, GTP (Global Telematics Protocol)

JapanProvide superior quality of navigation and cell phone services.

Kiwi navigation information standard

KoreaExtend wireless communication service and application.

KOTBA (Korea Telematics Business Association)

Jeju Telematics City

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TaiwanTaiwan

Industrial Technology Research Institute (ITRI) developed. Telematics devices based on X86 structure.

It integrates navigation and e-MAP, customer multimedia structure, Bluetooth, 802.11 etc.

The 2nd telematics system addition remote Vehicle Diagnostics System, Lane Departure Warning System, etc.

Yulon Motor, Quanta Computer, ASUS and Hon-hai are impetus “IA integrate Car plan” to integrate with IT and Automotive industries.

Before Market: Focus on Inter-communication between navigation and other devices.

After Market: Focus on multimedia and pastime.

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ITS in TaiwanITS in Taiwan 先進交通管理服務 ( Advanced Traffic Management Services, ATMS ) 先進旅行者資訊服務 ( Advanced Traveler Information Services, ATIS ) 先進公共運輸服務 ( Advanced Public Transportation Services, APTS ) 先進車輛控制安全服務 ( Advanced Vehicle Control and Safety Services,

AVCSS ) 商車營運服務 ( Commercial Vehicle Operations, CVO ) 緊急事故支援服務 ( Emergency Management Services, EMS ) 電子收付費服務 ( Electronic Payment System & Electronic Toll

Collection, EPS&ETC ) 資訊管理系統 ( Information Management System, IMS ) 弱勢使用者保護服務 ( Vulnerable Individual Protection Services, VIPS )

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Future Telematics – Concept TelematicsFuture Telematics – Concept Telematics

TrendsIn-vehicle computing conceptsDriver/passenger control of devicesRear seat entertainmentRear seat computingRear seat printing!

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Summary of Part 1Summary of Part 1

All commercial Telematics today use mobile phones as All commercial Telematics today use mobile phones as communication mediacommunication media

With various infrastructure installed, assured communication is possibleCosts are reasonable, and most spread wireless mediaRelatively large size data transmission is possible

Necessity for the Sophistication of TelematicsDiversification of data to be transmitted and increase in data volumes

• Sophistication of mobile phones and development of new• wide area wireless system

Future?• Telematics technology &

Application deployment will be widespread by 2010

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Talk outlineTalk outlineIntroduction of Telematics




Current Results

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DSRC—DSRC—A short range wireless technology for A short range wireless technology for TelematicsTelematics Applications Applications

Dedicated short-range communications (DSRC)One-way or two-way short- to medium-range wireless

communication channels specifically designed for automotive use and a corresponding set of protocols and standards.

Offering communication between vehicles and roadside equipments.

Having a range of up to 1,000 meters.Working in the 5.9 GHz band (U.S.) or 5.8 GHz band

(Japan, Europe) for ITS applications. Former standard used the 915 MHz band.

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New specifications for DSRCNew specifications for DSRC

Existing DSRC915 MHzRange < 30 metersData rate = 0.5 mbpsDesigned for ETC, but can be

used for other applicationsSingle unlicensed channelRequires special (custom) chip

set & softwareVehicle to roadsideCommand-response

New specifications5.9 GHzRange to 1000 metersData rate 6 to 27 mbpsDesigned for general internet

access, can be used for ETC7 licensed channelsUses open off-the-shelf chip set

& softwareVehicle to roadside & vehicle to

vehicleCommand-response & peer to

peer

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Based on IEEE 802.11aBased on IEEE 802.11a

High speed road impacts physical layerVery short latency (<50ms) impact on MAC layerRandom MAC addresses to preserve privacyIPv6 for network layer (with header compression allowed)Multiple stack options above network layerSupport for in-car networks

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DSRC for DSRC for TelematicsTelematicsDSRC allows high-speed communications between vehicles and the

roadside, or between vehicles, for Telematics; Potential DSRC applications for public safety and traffic

management include: Intersection collision avoidance Approaching emergency vehicle warning Vehicle safety inspection Transit or emergency vehicle signal priority Electronic parking payments Commercial vehicle clearance and safety inspections In-vehicle signalRollover warning Probe data collection Highway-rail intersection warning

Technically, meet the requirements of Telematics very much!

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Demo from MercedesDemo from Mercedes (1/2)(1/2)

Sometimes someplace instead of everywhere alwaysSometimes someplace instead of everywhere alwaysCan be targeted to specific lanes, directions of travel but

not for wide area coverage

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

Good News/ Bad NewsGood News/ Bad NewsRoadside Unit PlacementRoadside Unit Placement

General Internet AccessGeneral Internet Access On-Demand/Dynamic NavigationOn-Demand/Dynamic Navigation

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Demo from Mercedes (2/2)Demo from Mercedes (2/2)

Traffic AdvisoriesTraffic AdvisoriesTraffic AdvisoriesTraffic Advisories Use Vehicles as Traffic ProbesUse Vehicles as Traffic Probes

Travel AssistantTravel AssistantMore on Video from Mercedes

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Standards ProgramStandards Program

• Industrials

• Standard organization

• Academia

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Layered view for DSRC StandardsLayered view for DSRC Standards

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ClarificationClarification

WAVE (Wireless Access in Vehicular Environments)mode of operation used by IEEE 802.11 devices to operate in the DSRC

bandDSRC (Dedicated Short Range Communications)

ASTM Standard E2213-03, based on IEEE 802.11aname of the 5.9 GHz Band allocated for the ITS communications

IEEE 802.11pbased on ASTM Standard E2213-03currently draft standard

DSRC DevicesIEEE 802.11 systems using the WAVE mode of operation in the DSRC

band

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WAVE StandardsWAVE Standards IEEE 1609.1: WAVE Resource Manager

Defines Resource Manager Application Application data read/write protocol between RSU and OBU First application available for testing purposes

IEEE 1609.2: WAVE Security Services for Applications and Management Messages Defines 5.9 GHz DSRC Security (formerly IEEE 1556)

Anonymity, Authenticity and Confidentiality IEEE 1609.3: WAVE Networking Services

Provides description and management of the DSRC Protocol Stack Application interfaces Network configuration management WAVE Short Message (WSM) transmission and reception

IEEE 1609.4: WAVE Multi-Channel Operation Provides DSRC frequency band coordination and management

Manages Lower Layer usage of the seven DSRC channels Integrates tightly with IEEE 802.11p

IEEE 802.11p: Wireless LAN Medium Access Control (MAC) and physical layer (PHY) specifications: Wireless Access in Vehicular Environments (WAVE) Defines the Lower Layers of the communications stack

Radio wave forms and wireless medium access procedures

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WAVE Protocol StackWAVE Protocol Stack

Lower Layers

Networking Services

Upper Layers

Radio Service Security

IEEE 1609.1, et al.

IEEE 1609.3

IEEE 1609.4, IEEE 802.11p

WAVE device

Medium

IEEE 1609.2

Application Security

IEEE 1609.2

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Industrial ConcernsIndustrial Concerns

DSRC Devices R&DApplications and CostsMarket IssueDeploymentStandardization

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Academia ConcernsAcademia Concerns

WAVE Protocol establishmentCurrently accomplished drafts

1609.1, 1609.2, 1609.3, 1609.4, 802.11p, …Newly defined

1609.5, 1609.6

Fundamental StudiesDSRC technique developmentPerformance Enhancement

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CooperationCooperation

DSRC Devices R&DApplications and CostMarket IssueDeploymentStandardization

Applications and CostStandardizationWAVE protocol establishment - 1609.5, 1609.6DSRC technique Performance enhancement

WAVE protocol establishment - 1609.5, 1609.6DSRC technique Performance enhancement

Academia Concerns

Industrial Concerns

Cooperation

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Summary of Part 2Summary of Part 2The Internet is not being brought to the vehicle, but the vehicle will

become a part of the Internet;

Communications will be critical to all future transportation systems;

Technically, DSRC allows high-speed communications between vehicles and the roadside, or between vehicles, and affords various applications for Telematics;

Different Workgroups and organizations are doing the standardizing work;

Researches on Telematics should be done in company with standardizing and technical study.

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Current Results

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Research Topics in TelematicsResearch Topics in Telematics

Telematics are: Application/service-centric and practical R&D topics But borrowing some pure research-centric

techniques/knowledge to real life research So Research Topics in Telematics are Cross point of:

Application/Service Requirements Practical System Development and Deployment Inevitable Hardness in Physical Environments Current and Future Technologies

What and How to do in Telematics Research? Fundamental Studies Techniques Developments

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Fundamental Studies in TelematicsFundamental Studies in Telematics

Q1: Origins of the special technical problem in Telematics

Q2: What are the features of Vehicular Telematics?

Q3: How to deal with these features?

Q4: What can be supplied in Telematics?

A1: Mobility of vehicles

A2: Measurement Study for Vehicular Environment

A3: Techniques R&D to fit Vehicular Environment

A4: Challenge current Applications and Develop new

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Mobility ModelingMobility Modeling

Nodes tend to spend more time at intersectionsIncreases interference in this regionCan reduce connectivity

Buildings further reduce connectivity betweennodes on different streetsNodes often travel in opposite or orthogonal directionsShort interaction time window

Vehicular congestion slows nodesCan stabilize topology, but can reduce overall connectivity

A new mobility model for VANETs is needed…

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Measurement Studies for Vehicular EnvironmentMeasurement Studies for Vehicular Environment

Origins of difficulties in Vehicular TelematicsSpeed!!!

ResultsDoppler EffectBad quality channel condition

Chain Reaction Unstable LinksUnstable ConnectivitiesHardness in service provisions

Need quantitative studies to give detailed results

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A case of the Problems with Status Quo A case of the Problems with Status Quo Wireless StandardWireless Standard Discontinuous coverage Before Transfer need Scanning, Authentication, Association, DHCP

Discovery, ARP Req Status Quo TCP limitation

Get out of Coverage

AuthenticationAssociation

DHCP DiscoverArp Req

Ready to Transfer Content?

A long period (avg: 600ms) to tune to the right channel

Get into coverage, scanning

•Mean time to establish connectivity: 12.9 seconds

•A 60Km/H car will travel more than 200 meters in 12.9 Sec

•Considering retransmissions due to worse link quality

•Maybe no content is delivered during such encounter

Even Established in

time

Status Quo TCP will also

limit the transmission

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Techniques and Applications DevelopmentTechniques and Applications Development

ApplicationsNormal Data Acquisition and

Delivery

Mediastream or Interactive Application

Emergency services

Location aware services

Various of services

TechniquesDelay Tolerant or Disruption

Tolerant Network Techniques, Opp. Routing, etc.

Heterogeneous network coverage with seamless handoff techniques, Mesh network, Diversity, Multihoming, etc.

Channel allocation with priority, Service differential, etc.

GPS technology, localization techniques

mobile-P2P, service discovery, middleware, etc.

Techniques and Applications are tightly related.

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Research Topics in Telematics (1/2)Research Topics in Telematics (1/2)Vehicular network architectures and protocolsVehicular network performance modeling and analysisVehicular network medium access control and routing protocolsVehicular network flow and congestion controlQuality of Services (QoS) provisioning in wireless-enabled ITS

systemsTraffic management, vehicle control, and safety related applications

for ITS systemsNetworking and information services for users on the roads (by

automobiles, trains, planes, or ships)Cross-layer design and optimization for vehicular ad hoc networksMobility management and intersystem handovers Incentives, cooperation, and reputation systems

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Research Topics in Telematics (2/2)Research Topics in Telematics (2/2)

Routing protocols for active safety in VANETEmerging applications such as content distribution, infotainment,

Internet access, etc.Challenges of V2V, V2I, and I2V wireless communicationUse of wireless technology within carsSecurity issues in VANET and trustworthy networkingPropagation issuesEmerging inter/intra-vehicle and infrastructure-to-vehicle wireless

communication technologiesSimulation models and testbeds for VANET Implementation and field tests of VANET systemsPotential modifications needed to improve the DSRC standard

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A Layered ViewA Layered View Mobility Modeling PHY Layer

Channel modeling Modulation and coding Power control and scalability issues

MAC Layer Multi-channel organization and operation link control Queueing and Schedule Load Balance

Network Layer Topology Control Routing Handoff

Transport Layer Connection control

Application Layer Service provision & discovery

Multi layer related Security & Privacy Network management

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Summary of Part3Summary of Part3

Research on Telematics:Most problems are caused by the Speed!Researches usually aim at this special condition of vehicular

environmentChanges to traditional problems in each layer, e.g.:

PHY Layer: Power consumptions are no longer problemsMAC Layer: Link quality degrades due to packet loss rather than

collisions (in V2I cases)Network Layer: Mobility Management shows greater significanceTransport Layer: Congestion control may be not the main problemApp Layer: Various service, new and maybe different priority

e.g., safety app. vs delay tolerant app.

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Current Results

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Our research results (1/2) Our research results (1/2)

Research Papers SIP-based Network MobilityA Network-Aware P2P File Sharing System over the

Wireless Mobile Network EnvironmentLayer 7 Multimedia Proxy Handoff using Anycast/Multicast

in Mobile Networks

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Our research results (2/2)Our research results (2/2)

Research Project - WAVE-based DSRC Safety Applications Development (Project of Institute for Information Industry)Intersection Collision WarningEmergency Vehicle Approach

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SIP-based Network MobilitySIP-based Network Mobility(SIP-NEMO)(SIP-NEMO)

Chung-Ming Huang, Chao-Hsien Lee, and Ji-Ren ZhengLaboratory of Multimedia Mobile NetworkingDepartment of Computer Science and Information EngineeringNational Cheng Kung UniversityTaiwan, R.O.C.

IEEE Journal on Selected Areas in Communications, VOL. 24, NO. 9, pp. 1682- 1691, Sep. 2006. (SCI, EI)

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Host MobilityHost Mobility

A single mobile node (MN) changes its point of attachment in the Internet.

Mobile IPv6Each MN has 2 IP addresses (2-tier addressing)

Home Address (HoA)permanent address in the home network

Care of Address (CoA) temporary address in the visited/foreign network

Keep the “binding” correctthe mapping between HoA and CoA

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Network MobilityNetwork Mobility

• A set of hosts moves together from one location to another.

• Manageability Power saving Low complexity Few handoffs Internet

on-board unit

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IETF NEMO BSPIETF NEMO BSPExtension of Mobile

IPv6

Mobile Router (MR)Operates Mobile IPv6Establishes a bi-directional

tunnel to its corresponding Home Agent (HA)

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Control signaling protocol for establishing, maintaining and terminating multimedia sessions.Pre-callMid-call

Session Initiation Protocol (SIP)Session Initiation Protocol (SIP)

SIP Mobile IP

Application layer protocol Network layer protocol

Indirect routing in IPv4

Encapsulation overhead

Authentication of redirection

IP stack needs to be changed.

Host/Terminal Mobility, Session Mobility, Personal Mobility, and Service Mobility

Host/Terminal Mobility

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SIP-based Network MobilitySIP-based Network MobilityThree types of SIP Back-to-

Back User Agent (B2BUA)SIP Home Server (SIP-HS)SIP Network Mobility Server

(SIP-NMS)SIP Foreign Server

(SIP-FS)Two Lists

Binding ListSession List

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Header TranslationHeader TranslationIn order to avoid problems due to tunneling

For a REGISTER request

•For an INVITE request

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Route OptimizationRoute Optimization

[email protected] (URI)

[email protected] (Contact)

[email protected] (URI)

[email protected]. com.tw (Contact)

[email protected]

[email protected]

sip-nms@visited. network. com.tw

sip-nms@visited. network. com.tw

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NestingNestingSIP-NEMO can keep almost the same performance even if

the nesting level is increasing.

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A Network-Aware P2P File Sharing A Network-Aware P2P File Sharing System over the Wireless Mobile Network System over the Wireless Mobile Network EnvironmentEnvironment

Chung-Ming Huang, Tz-Heng Hsu and Ming-Fa Hsu,Laboratory of Multimedia Mobile Networking

Department of Computer Science and Information Engineering

National Cheng Kung UniversityTaiwan, R.O.C.

IEEE Journal on Selected Areas in Communications (JSAC), VOL. 25, NO. 1, pp.204-210, January 2007.

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IntroductionIntroduction : P2P : P2P Overlay NetworksOverlay Networks

Application layer Flexible design

TopologyMaintenanceProtocol

Transparent to the underlyed IP network

DisadvantagesLonger latencySetup and maintenance

overload

overl ay network

physi cal network

routers

the overlay link

the physical link

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Introduction (cont)Introduction (cont) Traditional P2P file sharing applications do not support mobility,

making it difficult for mobile users to retrieve files in wireless mobile networks.

Two concerns that affect resource discovery and retrieval in wireless

mobile networks arePeers’ movements in wireless mobile networks Peers’ join and leave in a P2P file sharing network.

The routing path’s change may affect the performance of data transmission, e.g., the transmission rate.

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Introduction (cont)Introduction (cont)

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Introduction (cont)Introduction (cont) To enable continuous resource discovery and file retrieval for mobile users in

wireless mobile networks, we proposed a novel network-aware P2P architecture.

The proposed network-aware P2P file sharing architecture has a mobility-aware file discovery control (MAFDC) scheme that can obtain fresh status of

participant peers and reduce the number of messages that are used to discover peers in the wireless network environment

a resource provider selection (RPS) algorithm to select a new resource provider for mobile peers that encounters connection broken in wireless mobile networks

an identical file matching (IFM) algorithm to identify whether two files in a P2P file sharing network are the same or not.

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System ArchitectureSystem Architecture

The network-aware P2P architecture divides a P2P file sharing network into multiple network-aware clusters.

Peers are assigned to a network-aware cluster using a network prefix division.

All files within the same cluster are searched first, which can speed up the resource discovery in the wireless mobile network environment.

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Mobility-Aware File Discovery Control SchemeMobility-Aware File Discovery Control Scheme

When peers leave a P2P file sharing network, hosts that retrieve files from these peers will lose connection and the data transmission will be interrupted.

Sending discovery messages periodically is a way to obtain fresh status of peers that share files.

However, it may waste network bandwidth if each mobile peer sends messages periodically to discover new peers.

To solve this problem, we propose a mobility-aware file discovery control (MAFDC) scheme to reduce the number of messages that are used to discover resource providing peers in the wireless mobile networking environment.

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Mobility-Aware File Discovery Control SchemeMobility-Aware File Discovery Control Scheme

There are two kinds of query modes for mobile peers to discover new resource providing peers: Publish-subscribe query mode

to reduce the number of messages to discover new resource providing peers. Continuous query mode.

to solve the resource discovery problem when a mobile peer u is located within a firewall.

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Layer 7 Multimedia Proxy Handoff using Layer 7 Multimedia Proxy Handoff using Anycast/Multicast in Mobile NetworksAnycast/Multicast in Mobile Networks

Chung-Ming Huang and Chao-Hsien LeeLaboratory of Multimedia Mobile NetworkingDepartment of Computer Science and Information EngineeringNational Cheng Kung UniversityTaiwan, R.O.C.

IEEE Transactions on Mobile Computing, VOL. 6, NO. 4, pp. 411-422, Apr. 2007. (SCI, EI)

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Three-tier ArchitectureThree-tier Architecture

Traditional Advantage : CacheReduce the initial waiting timeSave bandwidth consumption

The 3-tier architecture can help to improve performance due to handoff.From one network to another one

Proxy servers can adapt the quality of requesting data.From one device to another one

Proxy servers can determine the session status of the same client.

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Problem StatementProblem Statement

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Taipei

Taichung

Tainan

Kaohsiung

Subnet B

Subnet A

Internet

Server

Proxy A

Proxy BMobile Node

Why does the MN still connect to the server via Proxy A ?

L7 Proxy HandoffRegarding user

mobility, clients should switch their own proxies dynamically.

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Issue 1: Proxy SelectionIssue 1: Proxy Selection

How to determine the most suitable proxy as the next proxy?Many proxy servers are distributed in the Internet.Each proxy provides each MN different qualities of services.

We adopts “application-layer anycast”.A packet targeted to an anycast domain name (ADN) is

routed to the most appropriate node.The meaning of “most appropriate” is defined by users via

anycast metrics.

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Client-driven Proxy SelectionClient-driven Proxy SelectionProxy servers are divided into

anycast groups based on its located subnet.IPv6 hierarchical addressing

We use one pre-defined site-local multicast address as the ADN.

Group B

FF35::101

Group A

FF35::101

Media Server

Proxy Proxy

Proxy

Proxy

Proxy

Proxy

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Issue 2: Buffer ForwardingIssue 2: Buffer ForwardingHow to recover the original session in the next proxy?

The next proxy may cache useless data for this MN.The MN needs to wait a period of time to let the next proxy request data

from the server.

We takes “IPv6 multcasting” into consideration.

the next proxy’s joining the multicast group

the original proxy’s leaving the multicast group>

83

Session Recovery SchemeSession Recovery Scheme

84

Performance EvaluationPerformance EvaluationWithout proxy handoff support

85

Performance EvaluationPerformance EvaluationWith proxy handoff support

86

Intersection Collision WarningIntersection Collision Warning

Chung-Ming Huang, Shih-Yang Lin, Chia-Ching Yang, Chih-Hsun Anthony Chou

Project of Institute for Information Industry - WAVE-based DSRC Safety Applications Development

87

Intersection SafetyIntersection Safety

A

B

Vector

A

BA

B

Collide

After Several Seconds

OR Safe

How to know it is safety or not before several seconds?

88

Intersection Collision Warning (ICW)Intersection Collision Warning (ICW)

GoalsProvide accurate pre-warning information before several

seconds.Pre-warning information can help drivers safely driving on

roads.Reduce probability of accident occurs.Warning level can be defined by the user himself.

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Three parameters provided by ICWThree parameters provided by ICWCPA (Closest Point of Approach)TCPA (Time to Closest Point of Approach)DCPA (Distance to Closest Point of Approach)

A

B

Vehicle ATCPA : 3 sDCPA : 4 mWarning : Safety

Vehicle BTCPA : 3 sDCPA : 4 mWarning : Safety

90

System structureSystem structure

Part 1 : Information Collection

Part 2 : Calculation

Inter-Vehicle Communication

Relationship Information, RI

Vector Info.

Course Info.

Warning

HighMiddle

Low

CPACalculation

Collision Warning

Part 3 : StorageSaving relation information to

Storage

Filter

RI includes position information, velocity, direction, acceleration, vehicle identify, etc.

91

SimulationSimulation

Using NS-2 simulation software.Based on WAVE communication.

92

Results - IResults - I Number of vehicles : 2 Number of lanes : 2 Included angle : 10, 30, 45, 60, 90

Lane 2

A

B

α = 10, 30, 45, 60, 90

Accuracy Rate : Whether or not send out the warning message before vehicle collides.

ICW accuracy rate : 100%

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Results - IIResults - II Number of vehicles : 40~80 Number of lanes : 4 Included angle : 90

Accuracy Rate : Whether or not send out the warning message before vehicle collides.

6000m

6000m

Line 1

Line 2

Line 3

Line 4

ICW Accuracy

98

98.5

99

99.5

100

100.5

10 15 20 25 30 35Velocity (m/s)

Acc

urac

y (%

)

40 Vehicles

60 Vehicles

80 Vehicles

94

EmergencyEmergency Vehicle Approach Vehicle Approach

Chung-Ming Huang, Chun-Yu Tseng, Chia-Ching Yang, Chih-Hsun Anthony Chou

Project of Institute for Information Industry - WAVE-based DSRC Safety Applications Development

95

Emergency Vehicle ApproachEmergency Vehicle ApproachDesign a mechanism for emergency vehicle to reach

destination quickly and safelySave timeNotify the approaching warning to nearby vehiclesHandle exception accident in the route of emergency vehicle

Traffic jamCar accidents

96

System ArchitectureSystem ArchitectureThere are four components in our proposed system

Two types of vehiclesEmergency vehicleNearby vehicles

There is a centralized server with the operations of management and calculation

RSU (road side unit) are deployedThey can forward/broadcast the message

Upload traffic information (average speed) to server periodically

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AlgorithmsAlgorithmsPath arrangement

Paths for emergency vehicles to pass is arranged by ServerDPA (dynamic path arrangement) mechanism

Dynamic(D) pathWithout DPA mechanism

Primary(P) path Secondary(S) path P-S path

A* algorithm is adopted to determine the P/S/D pathAdjust weight to avoid overlap between P and S

Server adopt BFS to determine the P-S path

98

Data disseminationData dissemination

IPA (Initial Path Arrangement) messageSent by emergency vehicle to get P,S and P-S path initially

Evacuation messageSent by emergency vehicle to notify the warning to nearby vehicles

Traffic informationAdopted by RSUs to upload traffic information to server

Alert messageSent by server to notify traffic accidents to emergency vehicle

DPA (Dynamic Path Arrangement) messageEmergency vehicle communicates with server by this message to

maintain a dynamic path

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Experimental result (1)Experimental result (1)• Optimization of P, S and P-S path

In A* algorithm– Weight value (cost of edge) is assigned to every edge– To avoid overlap between P and S, we define the weight factor of P (WP),

which is larger than 1 After calculation of P, weight value of each edge in P is multiplied by WP

Then cost of each edge in P is become larger, they will have lower possibility to be selected during calculation of S In the experiment

If WP ↑, then cost of S ↑ If WP ↑, # of S ↑

In condition : WP <1.1 Results shows that appropriate WP is around 1.08~1.12

100

Experimental result (2)Experimental result (2)

We compare the cost of three different mechanisms used by emergency vehicle (EV) in certain condition:Condition 1: accident occurred in primary path

– Performance metrics : average cost The time spent by emergency vehicle (from start point to destination)

Result• Original path

– EV takes P-path – Average cost: 443.70 (seconds)

• Alternative path– EV takes P-path first, then switches to S-path when accidents occurred in P-

path– Average cost: 306.24

• DPA– EV periodically connects to server to maintain the dynamic path– Average cost: 252.41

Performance : DPA(best) > A. > O.

101

Experimental result (2)Experimental result (2)

Condition 2: accidents occurred in both primary path and secondary pathResult

• Original path– EV takes P-path – Average cost: 436.61

• Alternative path– EV takes P-path first, then switches to S-path when accidents

occurred in P-path – Average cost: 473.43

• DPA– EV periodically connects to server to maintain the dynamic path – Average cost: 255.68

Performance : DPA(best) > O. > A.

P-S path is additional path

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Potential ResearchesPotential Researches

Vehicular Telematics have great research potentials, due to:New Services never stop coming out;Wireless communication’s bother from speed inherently existsTraditional techniques usually aim at fixed or low mobility

scenarioMore to do?

As new standards or drafts appears, measurement may be differentTechniques to improve the performance for new standards or draftV2V, V2I or Hybrid architecture may be harnessed for different

servicesApplication with location information with and without GPS (for

sometimes GPS is not available, such as tunnel or in-building carport)

Special application related

103

Conclusion of the talkConclusion of the talk

Telematics is a promising Technology and Research area

Industry, Standard Org. and Academics all show great interests on it

Challenging Researches aim at the technical and standardization problems in provisions of various of services under vehicular condition

Innovation and brainstorming are desired to push Telematics further forward

104

ThankThanks!s!ThankThanks!s!

Documents

1 Prof. Chung-Ming Huang Introduction to Telematics and ITS research topics National Cheng Kung University Department of Computer Science and Information