Introduction to Vehicular Ad Hoc Networks Chia-Jui Tsai 2007/3/25

Outline Introduction Choice Technology and Service Research Challenges Selected Research Results GST Telematics Platform Scalability for Message Dissemination Conclusion

Introduction Vehicular ad hoc networks (VANETs) ,a subclass of mobile Ad Hoc networks (MANETs). is a promising approach for future intelligent transportation system (ITS). The direct communication between vehicles using an Ad Hoc network, referred to as inter-vehicle communication (IVC) Car-to-car communication(C2CC) vehicle ad hoc networks (VANETs)

Introduction(Cont.) 智慧型運輸系統 (ITS, Intelligent Transportation System)乃是應用先進的電子，通信，資訊與感測等技術，以整合人，路，車的管理策略，提供即時(real-time)的資訊而增進運輸系統的安全，效率及舒適性，同時也減少交通對環境的衝擊。 ITS的技術骨幹 感測技術 感測技術可用於車內及道路基礎建設，主要是獲取交通、道硌與氣象等資訊，若再搭配多重感測資料的整合技術，更可提供24小時且不受天又影響的資訊收集服務。 電腦技術 電腦技術係用於高速處理得自感測系統的大量資料，而將其轉換成有用的資訊。 通信技術 無線及有線的通信技術可迅速地將大量資訊傳送到車輛、攜帶型

Motivation for VANET The main goal of VANET is increased driving comfort and safety. Use communication for new services Collision warning Up-to-date traffic information Active navigation services Weather information

Choice Technology Wireless Access Technologies IEEE 802.11 WLAN GPRS/UMTS Dedicated Short Range Communication (DSRC) IEEE 802.11p (C2C Comm.) IEEE 1609

DSRC Concept ITS重要建置之一，專用於短距離之單向或雙向通訊無線通訊 路側系統(Road Side Unit, RSU)與車輛單元(On-Board Unit, OBU)之通訊 車輛單元(OBU)與車輛單元(OBU)之通訊

DSRC Standards 歐、美、日等國之標準發展

IEEE 802.11p 又稱WAVE；Wireless Access in the Vehicular Environment 設定上是從IEEE 802.11來擴充延伸，來符合智慧型運輸系統（Intelligent Transportation Systems，ITS）的相關應用 應用的層面包括高速率的車輛之間以及車輛與5.9GHz（5.85-5.925GHz）波段的標準ITS路邊基礎設施之間的資料數據交換 按照官方正式的802.11工作計劃時間表，預定將於2009年4月公佈核定的802.11p修正案。

IEEE 1609 IEEE 1609標準則是以IEEE 802.11p通訊協定為基礎的高層標準 IEEE1609制定的目的是提供一個將車輛的主要系統的資訊(包含引擎，傳動系統，煞車，懸吊系統等)與道路的基礎架構兩者相溝通的機制，它在 5.9 GHz波段下操作，可與手機共同提供高速率資料。使用IEEE 802.11系列的無線區域網路通訊標準802.11p(由IEEE 802.11a發展而來)作為底層的通訊技術，同時採用IPv6作為上層的通訊協定。

IEEE 1609(Cont.) IEEE1609包括四個部份，目前所有的技術內容已經都審核通過，進入測試使用的階段 (1)IEEE 1609.1 -- WAVE Resource Manager ，其中規定了多個遠程應用和資源管理間的控制互換流程。 (2)IEEE 1609.2 -- WAVE Security Services for Applications and Management Messages ，其中包括了WAVE訊息安全抵制竊聽、電子欺詐和其他襲擊的方法。 (3)IEEE 1609.3 -- WAVE Networking Services，其中規定了通信協議的網路層與傳輸層。 (4)IEEE 1609.4 -- WAVE Multi-Channel Operations，提供了IEEE 802.11p MAC對WAVE的支援。 http://www.standards.its.dot.gov/fact_sheet.asp?f=80

Choice Service Service Types Car-to-Car Services Car-to-Infrastructure Services Portal-based Services

Possible Services for C2C Networks Car-to-Car Services Exchange of traffic information Exchange of weather or road conditions Car-to-Infrastructure Services Active road side infrastructure Road Side Units (RSU) as information points Portal-based Services Use of a Telematics platform Services like „Pay-as-you-drive“ insurance

Telematics platform Telematics一詞是由”Telecommunication”與”Informatics”所組成

Research Challenges for VANET Protocols and Wireless Access Scalability Problem Robust and reliable communication even at high speeds Efficient data dissemination schemes for large networks (>>100 nodes) Integration and Definition of Security and Privacy Realization of efficient trust environments (PKI) Reliability of nodes, routes, and messages Sufficient anonymity for mobile nodes

Overview of Selected Research Results

The GST Telematics Service Platform GST: Global System for Telematics Vision: Standard for Vehicular Telematics Platforms Open platform with reconfigurable services

GST: Project Details & Status Integrated EU project (FP6) Consortium with 49 companies OEMs: BMW, DaimlerCrysler, Fiat, Ford, Renault,Volvo Project Management: ERTICO Vision/Goal: Open environment ⇒ generate a de facto standard(業界標準 ) http://www.gstforum.org/

Scalability for Message Dissemination Many parallel information services → Network congestion New approach: Use context information to prioritize messages (benefit maximization)

Scalability for Message Dissemination(Cont.) M=message , V=vehicle , I=information ai=application-dependent factors bi=application-dependent subfunctions all weighted parameters have to be summed up and divided by the sum of all ai , leading to a benefit value between 0 and 1.

Conclusion 智慧型運輸系統(Intelligent Transport Systems,ITS) 在未來可能改變我們生活的面貌,對社會以及個人產生巨大的影響 而可被視為ITS的一個重要的key componet的Vehicular Ad-hoc Networks在未來的可研究性,發展性,以及商業應用上面的潛力 都是值得讓人期待的

Reference [1] Eichler, Stephan ; Schroth, Christoph ; Eberspächer, Jörg: “Car- to-Car Communication.” In: Proceedings of the VDE-Kongress - Innovations for Europe : VDE Verlag, 2006.- VDE-Kongress - Innovations for Europe.- Aachen, p. 6.- URL http://www.alexandria.unisg.ch/Publikationen/30950 [2] "Vehicular Ad Hoc Networks (VANETs): Challenges and Perspectives", 6th International Conference on ITS Telecommunications, 2006. [3] Dedicated Short Range Communication (DSRC);馮治軍、張孟俊、李進農;工研院電通所視訊與光通訊技術組傳輸技術部

Reference(Cont.) [4] http://zh.wikipedia.org/wiki/IEEE_802.11p [5] TIMO KOSCH, CHRISTIAN J. ADLER, STEPHAN EICHLER, CHRISTOPH SCHROTH, AND MARKUS STRASSBERGER,” THE SCALABILITY PROBLEM OF VEHICULAR AD HOC NETWORKS AND HOW TO SOLVE IT”, IEEE Wireless Communications • October 2006 [6] http://grouper.ieee.org/groups/802/11/Reports/tgp_update.htm [7] http://standards.ieee.org/announcements/PR_radiocomstd.html

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