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Self-organization of Vehicular Networks Mohamed Oussama CHERIF, Sidi-Mohammed SENOUCI, Bertrand DUCOURTHIAL, Ismail SALHI Orange Labs. REVE 2009 April 2 nd , 2009 IEF, Orsay - FRANCE. Self-organization of Vehicular Networks. Self-organization of vehicular networks
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Self-organization of Vehicular NetworksMohamed Oussama CHERIF, Sidi-Mohammed SENOUCI, Bertrand DUCOURTHIAL, Ismail SALHIOrange Labs REVE 2009 April 2nd, 2009 IEF, Orsay - FRANCE
Self-organization of Vehicular Networks • Self-organization of vehicular networks • Vehicular networks: Characteristics & Challenges • Self-organization • Problem & Motivation • CSP & CGP • CSP & CGP assets • CSP: Function & Performances evaluation • CGP: Function & Performances evaluation • Conclusion & perspectives 1 2 3
Self-organization of Vehicular Networks • Self-organization of vehicular networks • Vehicular networks: Characteristics & Challenges • Self-organization • Problem & Motivation • CSP & CGP • CSP & CGP assets • CSP: Function & Performances evaluation • CGP: Function & Performances evaluation • Conclusion & perspectives 1 Self-organization 2 3
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization Definition "A vehicular network is a communication network providing communications among nearby vehicles and between vehicles and nearby fixed equipments". Self-organization
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization • Power, processing and communication abilities • High mobility, network topology & connectivity • Frequent topology changes: Partition of the network Characteristics Self-organization • Socio-economical challenges (standardization development, Business models, Market introduction) • Technical challenges (Security, Mobility management, Routing, Addressing, Self-organization) Challenges
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization • Two types of Self-organization depending on the application • Proactive (e.g. Internet Access, File downloading, etc.) • Reactive (e.g. Data collection, Real-time info-traffic) What is self-organization? "Self-organization can be defined as the emergence of system-wide adaptive structure and functionality from simple local interactions between individual entities". C. Bettstetter Self-organization
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization Why self-organization? • Reduction of High mobility effects • Simplification of the management task • Reduction of the routing overhead • Reduction of the deployed infrastructure • Relaying on V2V communications to extend the range of roadside units • Minimization of the use of costly links (cellular links) and use of free frequencies (e.g. 802.11) to achieve data collection Self-organization
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization • Two collateral structures to self-organize the VANET (Vehicular Ad hoc Networks) efficiently • Virtual backbone • Clustering How self-organize? Self-organization Problem Dynamicity of clusters Great overhead
Self-organization of Vehicular Networks Vehicular Networks Problem & Motivation Self-organization Our Objectives • Minimization of the overhead due to the dynamicity of clusters • Stability of clusters • Optimization of use of the cellular links in case of data collection Self-organization Solution CSP & CGP
CSP: Cluster-based Self-organizing Protocol • Self-organization of vehicular networks • Vehicular networks: Characteristics & Challenges • Self-organization • Problem & Motivation • CSP & CGP • CSP & CGP assets • CSP: Function & Performances evaluation • CGP: Function & Performances evaluation • Conclusion & perspectives 1 2 CSP & CGP 3
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances • CSP & CGP rely on fixed clusters • Reduction of overhead • CSP elects cluster heads intelligently • Increase of clusters lifetime • CGP uses VANET multi-hop communication to aggregate data • Minimization of use of cellular links Assets CSP & CGP
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances • Division of a road portion into L-length segments • Each segment defines a fixed-cluster Architecture Overview CSP & CGP ECA • CSP: Two modules • Head election • Inter-segment transition
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Head Election • The current Head broadcasts a Head_Resign 1 4 5 7 3 8 6 2 • When receiving a Head_Req, the current head sends a Head_Ack to the elected candidate in which it includes its SGMT_TABLE CSP & CGP • Each vehicle that fulfills the following conditions is a candidate (VM . VN > 0) AND (M does not yet reached CZ+(N)) (VM . VN < 0) AND (M is situated in CZ(N) • The elected candidate sets its state to HEAD and broadcasts a Head_Update_Ack in its segment • Each candidate computes a E_Factor which reflects the estimated time to reach the CZ farthest border • The previous head sets its state to SUPER_MBR and other segment nodes update their head and stop sending Head_Req • Each candidate waits for a backoff which is inversely proportional to its E_Factor before sending a Head_Req
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Inter-segment transition • Each MBR verifies periodically (Pcheck) its position • If the MBR 'a' has to leave its current segment a … a a … CSP & CGP • It broadcasts a Mbr_Add_Req • The next segment Head adds 'a' to its table and sends a Mbr_Add_Notif to it • 'a' sends a Mbr_Remove request to its current Head • The current Head removes 'a from its table and sends a Mbr_Remove_Notif to it • 'a' updates its segment and sets its state to MBR
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Role of a SUPER_MBR • SUPER_MBR routes packets if neighboring heads can not reach each other in one hop CSP F-CSP Variant • No need of SUPER_MBR
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Simulation results Stability CSP & CGP Clusters Lifetime Vs Network Density
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Overhead CSP & CGP Overhead Vs Network Density
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Delivery Ratio CSP & CGP Delivery Ratio Vs Packet sending interval Delivery Ratio Vs Network Density
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances CGP: Function Data collection CH election tsel Inter- segment Relaying tcol tseg CSP & CGP No Data aggregation RSU? tagr Sending to Operator Yes tsta
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Head election Segment CSP & CGP • Eligibility computing • All nodes that have Back-off > 0 • If Back(j)=0 j eligible CH = j • End of CH-election stage Backoff > 0 Backoff = 0 CH Not eligible Initial state
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Sending data to the operator Operator TraficServices Cellular link
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances Simulation scenarios Scenario1 Per-node sending Scenario2 Per-CH sending CSP & CGP Scenario3 Seg-to-Seg sending
CSP: Cluster-based Self-organizing Protocol CSP & CGP assets CSP: Function & Performances CGP: Function & Performances V2V & V2I messages CSP & CGP V2I messages V2V messages
Self-organization of Vehicular Networks • Self-organization of vehicular networks • Vehicular networks: Characteristics & Challenges • Self-organization • Problem & Motivation • CSP & CGP • CSP & CGP assets • CSP: Function & Performances evaluation • CGP: Function & Performances evaluation • Conclusion & perspectives 1 2 3 Conclusion
Conclusion & perspectives • Proposition of CSP/CGP: A proactive/ reactive self-organizing architecture • CSP added values • Stability • Overhead reduction • High delivery ratio • CGP added values • Minimization of use of cellular links in case of data collection • Future Works • Extension of the simulation study • Handover between ECAs Conclusion
Thank you for your attention Contact • Mohamed oussama CHERIF • Orange Labs CORE/M2I • 2 Avenue Pierre Marzin • 22307 Lannion Cedex, France • Email: mohamed.cherif@orange-ftgroup.com • Tel: +33 2 96051292