1 / 58

V2V and V2I Communication

V2V and V2I Communication. 건국대학교 MBC Lab. Contents. V2I/V2V Communication Introduction. DSRC. WAVE. CALM. V2V Network Protocols. Projects and Standards. V2I/V2V Communication Introduction. Introduction. What is ITS? Intelligent Transportation Systems

amity-barrera
Download Presentation

V2V and V2I Communication

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. V2V and V2I Communication 건국대학교 MBC Lab

  2. Contents V2I/V2V Communication Introduction DSRC WAVE CALM V2V Network Protocols Projects and Standards

  3. V2I/V2V Communication Introduction

  4. Introduction • What is ITS? • Intelligent Transportation Systems • encompass a broad range of wireless and wireline communications-based information, control and electronics technologies • can provide : • help monitor • manage traffic flow • reduce congestion • provide alternate routes to travelers • enhance productivity • save lives, time and money

  5. Introduction • V2V/V2I Service Perspective ITS will be developed into next-generation Navigation, Safety, Convergence & Infotainment Services - Next-generation Navigation : Provide real time and bi-directional information - Safety : Anti-collision and safety service in intersection road - Convergence : Vehicle management and related services - Infotainment Service : Content download service such as movie and music V2V/V2I Communication Technology • V2V Multi-hop Communication : Safety, Group communication • V2I Communication : Convergence, Infotainment service

  6. Introduction • V2V Communication : Vehicle Multi-hop Networking • V2I Communication : Bi-directional Packet Communication RSE : Road Side Equipment TSP : Telematics Service Provider Cellular/WiBroBase-station TSP Server IPBackbone V2I GPS V2V RSE RSE Emergence Message Warning Message Warning Message Probe Data Real time Traffic Information Accident Occur

  7. Introduction (Examples-1) • WISDOM(V2I) Management - Traffic signal control (Optimization for bus, emergency car) - Driving speed control Information - Data Collection- Information Provision- Provide information to traffic information center Safety - Accident Avoidance

  8. Introduction (Examples-2) • VII(Vehicle Infrastructure Integration ) • Traffic signal violation warning • Public safety vehicle priority signal activation • Provide traffic information

  9. DSRC

  10. DSRC • What is DSRC (Dedicated Short Range Communications)? • an Transportation Specific Technology • a short to medium range (1000m max generally 300m) communications service • supports both Public Safety and Private operations (roadside to vehicle, vehicle to vehicle communication) • provide very high data transfer (6-27 Mbps) rates where minimizing latency in the communication link • Half duplex : One-way at a time • for ITS applications, working in the 5.9 GHz band (U.S.) or 5.8 GHz band (Japan, Europe)

  11. DSRC • Technical Characteristics • 5.850 to 5.925 GHz • Bandwidth = 75 MHz • Shared, but Transportation is primary

  12. DSRC • Operating Characteristics • IEEE 802.11p protocol • Vehicle speeds up to 100 mph (160km/h) • Low latency: 50 ms • Application priority: 8 levels • Channel 172: vehicle safety only • Security • Encrypt using Public Key Infrastructure (PKI) • Road Side Unit (RSU) Authentication • On Board Unit (OBU) Privacy

  13. DSRC • DSRC Standards • ASTM E2213 : Radio (Data Link) New IEEE 802.11p • IEEE 1609-1 : Application manager • IEEE 1609-3 : Network service • IEEE 1609-4 : Medium Access Control • IEEE 1556 : Security

  14. WAVE (IEEE 802.11p)

  15. WAVE • What is WAVE? • IEEE 1609 - Family of Standards for Wireless Access in Vehicular Environments • Focused on following issues: • Limitation of the lack of ubiquitous high-speed communications between vehicles and service provider • Limitation of the lack of homogeneous communications interfaces between different automotive manufacturers • define an architecture and standardized set of services and interfaces • enable secure vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I)

  16. WAVE • consists of four standards: • IEEE P1609.1 - Resource Manager • specifies the services and interfaces of the WAVE Resource Manager application • defines data flows and resources • defines command message formats and data storage formats • specifies the types of devices that may be supported by the OBU(On Board Unit) • IEEE P1609.2 - Security Services for Applications and Management Messages • defines secure message formats and processing • IEEE P1609.3 - Networking Services • defines network and transport layer services • defines Wave Short Messages • IEEE P1609.4 - Multi-Channel Operations • provides enhancements to the IEEE 802.11 Media Access Control (MAC) to support WAVE operations

  17. WAVE • characteristic • Max. Speed : 200Km/H • 1000 m range must support 1 Mbps • Approach : Active • Bandwidth : 75 MHz (5.850 - 5.925 GHz) • Modulation : QPSK OFDM • Channels : 7EA 10 MHz channels • Data Rate : • 10 MHz Channels : 6, 9, 12, 18, 24, and 27 Mbps • 20 MHz Channels : 6, 9, 12, 18, 24, 36, 48, and 54 Mbps • Max Tx Pwr : 28.8 dBm (at the antenna input) • RSU and OBU Sensitivity : • 82 dBm (QPSK) / - 65 dBm (64QAM)

  18. WAVE • WAVE : Scope

  19. WAVE • Protocol Stack MLME : MAC Layer Management Entity PLME : Physical Layer Management Entity WME : WAVE Management Entity WSMP : WAVE Short Message Protocol

  20. WAVE • OSI versus WAVE Model • Draft P802.11p: Wireless Access in Vehicular Environments (WAVE) • Defines the lower layers (PHY and MAC) communications stack • IEEE Std 1609.4™-2007: Trial-Use Standard for WAVE - Multi-Channel Operation • Provides frequency band coordination and management within the MAC layer • IEEE Std 1609.3™-2007: Trial-Use Standard for WAVE - Networking Services • Specifies operation and management of the communications stack WAVE Standard

  21. CALM (Continuous Air interface for Long and Medium range)

  22. CALM • What is CALM? • Continuous Air interface for Long and Medium range • ISO approved framework • Provide heterogeneous packet-switched communication in mobile environments • CALM framework supports user transparent continuous communications across various interfaces and communication media (802.11, 802.11p, 802.15, 802.16e, 802.20, 2G/3G/4G cellular systems, national ITS systems) • being developed by ISO TC204/WG16 – Wide Area Communications • CALM M5 = CALM - Microwave 5 GHz • CLAM

  23. CALM • Overall targets • Support continuous communications • Support ITS services and Internet services • Support of next generation applications: • Major push in Vehicle Safety Communication • New commercial applications made possible by high data rate & long range • Support master/slave and peer-peer modes • Support user transparent networking spanning multiple media, media providers and beacons • M5: No harmful cross-interference with regional DSRC standards • M5: Support relevant ASTM / IEEE 802.11 / ETSI Hiperlan modes

  24. CALM • Architecture CME : CALM Management Entity SAP : Service Access Point NME : Network Management Entity

  25. CALM • CALM Network Scenario(1)

  26. CALM • CALM Network Scenario(2)

  27. CALM • Selected CALM media • ISO 21212: 2G Cellular (GSM) • ISO 21213: 3G Cellular (UMTS) • ISO 21214: InfraRed • ISO 21215: M5 (802.11p) • ISO 25112: WiMAX (802.16e) • ISO 25113: HC-SDMA (802.20) • ISO xxxxx: Bluetooth (802.15) • ISO xxxxx: Ethernet (802.3)

  28. CALM • CALM M5 vs. 802.11p (WAVE) • WAVE PHY/MAC is IEEE 802.11p • CALM M5 incorporates WAVE and adds following features : • Global (European) 5 GHz spectrum • Regulatory domain (border) management • Directivity and EMC control • Regional DSRC cooperation • Multiple radios/interfaces/antenna management through network connection • GPRS/UMTS/+++ network interconnectivity

  29. V2V Network Protocols

  30. V2V Network Protocols • Issues of V2V protocols • Mobility • Highly dynamic, hence An on-going session suffers frequent path breaks • Bandwidth Constraint • Use the Bandwidth optimally by keeping the overhead as low as possible • Error-Prone Shared Radio Channel • Find paths with less congestion • Hidden and Exposed Terminal problem Mesh network and MANET routing protocols can solve these issues

  31. V2V Network Protocols • MANET • Mobile Ad-hoc NETwork • IETFWorking Group (1997.7) ※Infrastructure-less communication without static base-station or wired backbone network • < MANET(이동 애드-혹 네트워크) > • < 일반 무선 네트워크 >

  32. V2V Network Protocols • MANET Characteristic • Cannot assume, that every computer is within communication range of every other computer • can connect to Internet by Gateway • every nodes in MANET can be host or router • Dynamic topology • Self-starting • No administrator • Battery constraint, less computing power and mobility => needs another routing protocol different from wired-network < Independent> < connected to Infrastructure>

  33. V2V Network Protocols • Wireless Mesh Network Link Types Node Types Intra-mesh wireless links Stationary client access Mobile client access Internet access links Wireless routers Gateways Printers, servers Mobile clients Stationary clients

  34. GW V2V Network Protocols • Wireless Mesh Network : Gateways • Multiple interfaces (wired & wireless) • Mobility • Stationary (e.g. rooftop) – most common case • Mobile (e.g., airplane, busses/subway) • Serve as (multi-hop) “access points” to user nodes • Relatively few are needed, (can be expensive)

  35. V2V Network Protocols • Wireless Mesh Network : Wireless Routers • At least one wireless interface. • Mobility • Stationary (e.g. rooftop) • Mobile (e.g., airplane, busses/subway). • Provide coverage (acts as a mini-cell-tower). • Do not originate/terminate data flows • Many needed for wide areas, hence, cost can be an issue.

  36. V2V Network Protocols Converges Wireless Mesh network and MANET WirelessNetworking SingleHop Multi-hop Infrastructure-based (hub&spoke) Infrastructure-less (ad-hoc) Infrastructure-based (Hybrid) Infrastructure-less (MANET) 802.11 802.16 802.11 Bluetooth Cellular Networks Car-to-car Networks (VANETs) Wireless Sensor Networks Wireless Mesh Networks

  37. V2V Network Protocols What kind MANET Protocol is good for ITS/Telematics Networking? • V2V and V2I convergence • V2V Communication : MANET routing protocol • V2I Communication : Mesh network IPBackbone TSP Server RSE has a roll like a WMN gateway RSE RSE RSE Vehicles can be a wireless routers Data forwarded by MANET Protocol Data

  38. V2V Network Protocols • MANET Protocols - proactive and reactive routing Algorithms • Proactive(table-driven) • maintains fresh lists of destinations • maintains routes by periodically distributing routing tables • main disadvantages • Respective amount of data for maintenance • Slow reaction on restructuring and failures • Reactive(on-demand) • finds a route on demand by flooding Route Request packets • main disadvantages • High latency time in route finding • Excessive flooding can lead to network clogging

  39. V2V Network Protocols • MANET – Classification of Ad-hoc Routing Protocols

  40. V2V Network Protocols • MANET – DSDV (Table Driven) • Destination-Sequenced Distance Vector • Keep the simplicity of Bellman-Ford • Avoid the looping problem • Tag each routing table entry with a Destination sequence number • Allow fast reaction to topology changes • Make immediate route advertisement on significant changes in routing table • wait with advertising of unstable routes • Remain compatible in cases where a base station is available • Proactive • Each node maintains routing information for all known destinations • Routing information must be updated periodically • Traffic overhead even if there is no change in network topology • Maintains routes which are never used

  41. V2V Network Protocols • MANET – DSDV : Transmitting Route Information • Routing information is transmitted by broadcast • Updates are transmitted periodically or immediately when any significant topology change is available • Rules to set sequence number information • On each advertisement increase own destination sequence number (use only even numbers) • If a node is no more reachable (timeout) increase sequence number of this node by 1 (odd sequence number) and set metric =  • Full dump: all information from the transmitting node • Incremental dump: all information that has changed since the last full dump • Full dump if incremental dump exceeds one NPDU (network protocol data unit)

  42. V2V Network Protocols • MANET – DSDV : Route Selection • Update information is compared to own routing table • Select route with higher destination sequence number • Select the route with better metric when sequence numbers are equal.

  43. V2V Network Protocols • MANET – DSDV : Problem • DSDV requires a full dump update periodically  DSDV is not efficient in route updating • DSDV limits the number of nodes that can join the network • Whenever topology of a network changes, DSDV is unstable until update packets propagate through the network • DSDV is effective for creating ad-hoc networks for small populations of mobile nodes • DSDV is a fairly brute force approach, because connectivity information needs periodical update througout the whole network

  44. V2V Network Protocols • MANET – DSR (On-Demand) • On-demand route discovery • DSDV is a proactive protocol: maintains all topology information • DSR is a reactive protocol : maintains active routes • Routes automatically determined and maintained • No periodic packets => entirely on-demand • E.g. Routing advertisement, Link status sensing, Neighbour detection packets • Source routing • sender of a packet determines the complete sequence of nodes to forward the packet • No need to maintain information at intermediate nodes • reaction to topology changes more rapid => node caches multiple routes to destination • Avoids need to perform Route Discovery each time a route breaks

  45. V2V Network Protocols • MANET – DSR : main functions • Route Discovery: • Allows any host to dynamically discover a route to any other host in the ad hoc network. • A host initiating a route discovery broadcasts a route request packet • Each route request packet contains a route record • If successful, initiating host receives a route reply packet • The route is saved in the cache for future use • Route maintenance: • Host monitors the correct operation of routes in use

  46. V2V Network Protocols • MANET – DSR : Route Discovery • When node S wants to send a packet to node D, but doesn’t know route to D, it initiates a route discovery • Source node S floods Route Request (RREQ) • Each node appends its own address when forwarding RREQ • When node d receives RREQ it sends RREP to node S • Duplicate RREQ are discarded RREQ transmission S A RREP transmission B Broadcast E C F D G

  47. V2V Network Protocols • MANET – DSR : Route Reply (RREP) • Route Reply (RREP) is sent by reversing the route in Route Request (RREQ) • An intermediate node having a route to D can also send back a RREP RREP [S,A,B,C,D] S A RREP transmission B Broadcast E C F D G

  48. V2V Network Protocols • MANET – DSR : Advantages and disadvantages • Advantages • Reactive: routes maintained only between nodes who need to communicate • Route caching can reduce route discovery overhead • Disadvantages • Packet header size grows with route length due to source routing • Flood of route requests may potentially reach all nodes in the network • Care must be taken to avoid collisions between route requests and route reply propagated by neighboring nodes • Route Reply Storm problem • When a node sending RREP hears another RREP with a shorter route • Route reply storms also prevented by randomising delay time before sending route replies

  49. V2V Network Protocols • MANET – AODV (Ad-hoc On-demand Distance Vector) • Designed for MANETs with 10,000 to 100,000 nodes • Improves scalability and performance • Reduces dissemination of control traffic • Eliminates overhead on data traffic • Uses a broadcast route discovery mechanism • Every node maintains two separate counters • Sequence number • Broadcast-id (RREQ ID) • Node sequence number ensures loop freedom • Route’s “freshness” is decided by sequence numbers that each node maintains for all destinations in their routing table • Only active routes are maintained

  50. V2V Network Protocols • MANET – AODV : Route Discovery • Route discovery is initiated by broadcasting RREQ • When sender has no route to destination, or • Route to destination is invalid or expired • RREQ contains last known Dest Seq Num • When anintermediate node receives a RREQ, it records a “reverse” distance vector back towards the source then broadcasts the RREQ to its neighbors • A neighbor satisfies the RREQ sends a RREP back to the source • If an intermediate node is a destination or has a route entry for the destination • The route reply travels in the “reverse path” set up when the request packet was being forwarded

More Related