Redes Inalámbricas – Tema 5 Vehicular Networking

1. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility • Thanksto: • Knut Evensen - CVIS Chief Architect • John Moring • VinodKone • Jeonghoon Mo @ WINE LAB, Information and CommunicationsUniversity

2. Motivation • Safetyandtransportefficiency • InEuropearound 40,000 peopledieandmore than 1.5 millionsare injuredeveryyearontheroads • Trafficjamsgenerate a tremendouswasteoftimeandoffuel • Mostoftheseproblemscanbesolvedbyprovidingappropriateinformationtothedriverortothevehicle

3. Motivation: other scenarios

4. Motivation: other scenarios

5. Motivation: Sensor networks on the road • Position sensors • GPS, accelerometer, compass, tilt sensor • Environment sensors • CO2, cameras, thermometer, barometer, humidity sensor • Vehicle sensors • ignition, speed, engine speed, engine temperature, … • Vehicle interior sensors • camera, ID card reader Source: Davies, Cottingham, Jones: A Sensor Platform forSentient Transportation Research, LNCS 4272. Oct. 2006.

6. Technology trends • Wi-Fi (and possibly WiMAX) enabled vehicles are expected to be on the road within the next 3-5 years. Assuming 10% market penetration, this amounts to ~3-4 million Wi-Fi enabled vehicles in the UK, and ~20 million in the US in near future. • FCC has allocated 75 MHz of spectrum exclusively for V2V and V2I wireless communications (total UK 3G spectrum is ~ 70 MHz). In the UK and across the EU 30 MHZ of spectrum has been put aside for vehicular networks. • Vehicles equipped with WiFi can communicate directly with each other (V2V), and with the fixed infrastructure (V2I). They can form Vehicular Adhoc Networks (VANET)

7. Vehicular Ad Hoc Network (VANET) • VehicularAdHocnetwork (VANET) • Usesequippedvehiclesasthenetworknodes • Nodesmoveatwillrelativetoeachotherbut withintheconstraintsoftheroadinfrastructure • VANETs vs MANETs • RapidTopologyChanges • Highrelativespeedofvehicles => short link life • FrequentFragmentation • Chunks of the net are unable to reach nodes in nearby regions • SmallEffectiveNetworkDiameter • Apathmaycease toexistalmostasquicklyasitwasdiscovered (reactive routing) • LimitedRedundancy • The redundancy in MANETs is critical to providing additional bandwidth • In VANETs the redundancy is limited both in time and in function

8. So what kind of a system do we need? • Desirable system properties • Data collection and distribution in a local environment • Low information delivery latency • Cheap deployment and communication • Probable solutions • Cellular ? Service fees • Satellite ? High latency • Vehicular Networks ? • What is a vehicular network? • Vehicles are equipped with sensing, computing and wireless devices • Vehicles talk to road-side infrastructure (V2I) and other vehicles (V2V) • Has all the desirable properties

9. Vehicular Networks • What does road-side infrastructure (Infostation) mean? • High bandwidth & Low cost device • Coverage is less compared to a cellular base station • Advantages of infrastructure support • Low latency communication with vehicles • Gateway to the Internet and extend connectivity • Distributing time-critical data (e.g. accident notifications, traffic jam) near the affected area is efficient

10. Data Dissemination approaches and tradeoffs • Characteristics • High mobility • Dynamic topology • Receivers are a priori unknown • Large scale • High density • Low penetration ratio • Challenges • Maintaining routing tables is difficult • Scalability • Dealing with partitions Vehicular networks need to handle large amounts of data (emergency messages, videos etc) How do we efficiently disseminate this information?

11. Classification of Dissemination Approaches • V2I / I2V dissemination • Push based • Pull based • V2Vdissemination • Flooding • Relaying • How to deal with network partitions? • Opportunistic forwarding

12. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Push based dissemination • Infostation pushes out the data to everyone • Applications: Traffic alerts, Weather alerts • Why is this useful? • Good for popular data • No cross traffic  Low contention • Drawback • Everyone might not be interested in the same data

13. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Pull based dissemination • Request – Response model • Applications: Email, Webpage requests • Why is this useful? • For unpopular / user-specific data • Drawback • Lots of cross traffic  Contention, Interference, Collisions

14. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Flooding • Basic Idea • Broadcast generated and received data to neighbors • Usually everyone participates in dissemination • Advantages • “Good” for delay sensitive applications • Suitable for sparse networks • Key Challenges • How to avoid broadcast storm problem?

15. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Techniques to avoid the broadcast problem • Simple forwarding • Timer based • Hop limited • Map based / Geographic forwarding • Directed flooding • Aggregation • Drawbacks / Limitations of Flooding • Flooding in general • High message overhead  Not scalable • Map based / Geographic • Geographically closest doesn’t necessarily reflect the best path! • Depend on a location based service • Aggregation techniques tradeoff with accuracy

16. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Relaying • Basic Idea • Instead of flooding the network, select a relay (next hop) • Relay node forwards the data to next hop and so on • Advantages • Reduced contention  Scalable for dense networks • Key Challenges • How to select the relay neighbors? • How to ensure reliability?

17. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding How to select a relay neighbor? • Simple forwarding • Select the node farthest from source • Map based / Geographic forwarding • Closest to the destination • Abstract topology into a weighted directed graph • Drawback / Limitations • Locally best next hop may not be globally best !

18. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding How to ensure reliability? • Use RTS/CTS & ACK • Use indirect acknowledgments • Drawbacks / Limitations • RTS/CTS incurs lot of overhead • Interference affects indirect acknowledgments

19. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Opportunistic Forwarding • Problem with partitioned networks • Next hop is not always present • Opportunistic Forwarding • Basic Idea: Store and Forward • Challenge: What is the right re-broadcast interval? • Solutions • Broadcast repeatedly • Cache at infostations

20. V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Opportunistic: Drawbacks / Limitations • It is difficult to select the correct re-broadcast interval • Too soon  high overhead • Too late  doesn’t deal with partitions effectively • Maintaining a neighbor list induces high overhead and contention

21. Take Away

22. EU activities Political, Social and Economic Interests European Projects Harmonization Standardisation Convening Stimulation Moderation Editoring Dissemination ETSI CEN Specifications Group of Experts IEEE ITU Etc. Combination Clarification ISO C2C-CC IETF

23. Numerous Systems and Standards are under Construction… • A variety of EU and national projects elaborate • Protocol Architectures, • System Architectures, • High-Level Architectures ....... • Do we really need yet another Communication - Architecture ? Yes, because a comprehensive framework is needed to enable individually developed components to cooperate easily Source: TimoKosch, BMW

24. Joint development: ETSI TC ITS COMeSafety+ R&D projects Proposed European ITS Communication Architecture

25. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility • Thanksto: • Knut Evensen - CVIS Chief Architect • John Moring • VinodKone • Jeonghoon Mo @ WINE LAB, Information and CommunicationsUniversity

26. Wireless technologies for BWA

27. 802.11b at speeds II: speed dependence • Experiments performed under no-interference conditions (desert) • External antenna on the roof • UDP, TCP, HTTP • Observed some velocity-dependent packet loss Gass, Scott, Dio, 2005.

28. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility • Thanksto: • Knut Evensen - CVIS Chief Architect • John Moring • VinodKone • Jeonghoon Mo @ WINE LAB, Information and CommunicationsUniversity

29. WAVE Scope

30. Protocol Architecture

31. Trial Use Standards • IEEE Std 1609.1-2006 • Resource Manager • IEEE Std 1609.2-2006 • Security Services • IEEE Std 1609.3-2007 • Networking Services • IEEE Std 1609.4-2006 • Multi-Channel Operation • IEEE P802.11p - draft • WAVE MAC and PHY • IEEE Std 802.11-1999 • MAC and PHY

32. Full Use Standards in process

33. Overview of 802.11p (D7.0) • Specifies channelization in the 5.9 GHz band • Tunes some RF specs to allow highway operation • Defines a mode of operation “outside the context of a basic service set” • Removes latency-causing link setup operations such as authentication • Defines a Time Advertisement message

34. Overview of 1609.4 Multi-Channel Operation • Extensions to the 802.11/802.11p MAC • Management plane (MLME: MAC SubLayer Management Entity) • Manages optional regular switching between control channel and service channel • Queues regular time advertisements and/or service advertisements • Data plane (MAC) • Multiplexes/demultiplexes higher layer protocols (IPv6, WSMP) • Queues messages for transmission on the correct channels • Manages transmit message priority

35. Continuous access Alternating access Immediate access Extended access 1609 Channel Coordination examples Control Channel: management and (high priority) messages Service Channel: general user message and IP traffic For devices that don’t need continuous CCH access

36. 1609.4 Transmit Operation

37. Overview of 1609.3 Networking Services • Management plane (WME: WAVE Management Entity) • Generates contents of service advertisements based on higher layer info • Including IP configuration info and security credentials • Monitors received service advertisements for services of interest to higher layers • Estimates channel quality • Determines channel allocation/switching schedule to satisfy service requests • Data plane • Incorporates standard LLC and IPv6 • Introduces thin WAVE Short Message Protocol (WSMP) • Allows direct control of RF parameters (e.g., power, data rate) by the higher layer

38. Messages transmitted on request by higher layer Dest. MAC address, User Priority, Channel, Data rate, Transmit Power, PSID Messages delivered over the air by MAC address Unicast or broadcast Messages delivered up the stack by protocol and PSID EtherType distinguishes WSMP from IP WAVE Short Message Protocol (WSMP)

39. “Services” • Provider role • Sends out WAVE Service Advertisements (WSAs) on control channel • Includes info on services and channels • May include IP configuration info • In Trial Use, included timing info – now separate • Operates on identified service channel(s) at designated times for application data exchange • User role • Monitors WSAs for services of interest • May visit identified service channels at designated times for application data exchange • Allocation of radio resources to communication channels performed by 1609 stack based on higher layer request priority, service availability, device capabilities

40. KEY Optional Extension fields Lengths in octets WAVE Service Advertisement (WSA) contents Transmit Power Used 2D/3D Location Advertiser Identifier IP configuration info Secondary DNS Info about available services Info about service channels PSC IPv6 Address Service Port Provider MAC Address EDCA Parameter Set

41. This illustrates content from the higher layers, processed by the WAVE stack, and sent out as a service advertisement in an 802.11 frame Example of WAVE Transmit Protocol Layers IEEE 1609 IEEE 802.11

42. PSID & PSC • Provider Service Identifier (PSID) • 4 octets; values allocated by IEEE • Used as WSMP recipient address, and • Used as primary identifier of services in WAVE Service Advertisement • Presumably identifies type of information and encoding to be found on the SCH • Provider Service Context (PSC) • 0-32 octets; meaning determined by PSID • Used as optional secondary service descriptor in WSA • May indicate information sub-type, date tag, security context, etc.

43. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility • Thanksto: • Knut Evensen - CVIS Chief Architect • John Moring • VinodKone • Jeonghoon Mo @ WINE LAB, Information and CommunicationsUniversity

44. CALM - Overall • Continuous Air interface for Long and Medium distance • ISO TC204/WG16 – Wide Area Communications • Support user transparent continuous communications • CALM is the first open way to combine GPRS with vehicle-optimized WLAN technology. NOT a complicated collection of new, unproven radio technologies

45. Traffic Information - Audio Transfer - Streaming Traffic Information - Map Updates Traffic Information - Mobile Internet Traffic Information - Traffic Data Traffic Information - Traveller Information Traffic Information - Vehicle Registration (EVI) Traffic Information - Transit Vehicle Priority Traffic Information - Diagnostic Data Transfer Traffic Information - Video Transfer - Block Traffic Information - Audio Transfer - Block Traffic Information - Video Transfer - Streaming Traffic Information - Repair Service Record Traffic Information - Vehicle Software Updates VSC - OBU-to-OBU - Approaching Emergency Vehicle Warning VSC - OBU-to-RSU - Emergency Vehicle Signal Pre-emption VSC - OBU-to-RSU - Intersection Emergency Vehicle Approaching VSC - RSU to OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Cooperative Collision Warning CVO - Tractor-Trailer Interface CVO - Rollover Warning CVO - Electronic Border Clearance CVO - Weigh Station Bypass Clearance CVO - CVO Fleet Management CVO - Onboard Safety Data Transfer CVO - Tractor-Trailer Matching CVO - Transit Vehicle Data Transfer CVO - Vehicle Safety Inspection CVO - Drivers Daily Log OTHER SERVICES - Probe Data Collection OTHER SERVICES - Access Control OTHER SERVICES – Vehicle Manufacturer Info PAYMENTS - Toll Collection PAYMENTS - ITS Service Payment PAYMENTS - Other ePayments PAYMENTS - Rental Car Processing PAYMENTS - Parking Payment PAYMENTS - Food Payment PAYMENTS - Fuel Payment SAFETY - Vehicle-to-vehicle Data Transfer SAFETY – Highway-Rail Intersection Warning Services defined for 5 GHz medium - 1

46. VSC - RSU to OBU - Map Downloads and Updates VSC - RSU to OBU - Enhanced Route Guidance and Navigation VSC - RSU to OBU - GPS Corrections VSC - RSU to OBU - Adaptive Headlight Aiming VSC - RSU to OBU - Adaptive Drivetrain Management VSC - RSU to OBU - Merge Assistant VSC - RSU to OBU - Sign Information (warning assistance) VSC - RSU to OBU - Point-of-Interest Notification VSC - RSU to OBU - Curve Speed Warning VSC - RSU to OBU - Highway/Rail Collision Warning VSC - RSU to OBU - Animal Crossing Zone Information VSC - RSU to OBU - Low Bridge Warning VSC - RSU to OBU - Work Zone Warning VSC - RSU to OBU - Stop Sign Warning VSC - RSU to OBU - Keep Clear' Warning VSC - RSU to OBU - Wrong-way Driver Warning VSC - RSU to OBU - Left Turn Assistant VSC - RSU to OBU - Infrastructure Intersection Collision Warning VSC - RSU to OBU - Pedestrian Crossing Information VSC - RSU to OBU - Pedestrian/Children Warning VSC - RSU to OBU - School Zone Warning VSC - RSU to OBU - Stop Sign Movement Assistance VSC - RSU to OBU - Traffic Signal Warning VSC - RSU to OBU - Low Parking Structure Warning VSC - OBU-to-OBU - Pre-crash Sensing VSC - OBU-to-OBU - Intersection Collision Warning VSC - OBU-to-OBU - Enhanced Differential GPS Corrections VSC - OBU-to-OBU - Highway/Rail Collision Warning VSC - OBU-to-OBU - Vehicle-based Road Condition Warning VSC - OBU-to-OBU - Road Feature Notification VSC - OBU-to-OBU - Curve Speed Warning VSC - OBU-to-OBU - Visibility Enhancer VSC - OBU-to-OBU - Electronic Brake Lights VSC - OBU-to-OBU - Hybrid Intersection Collision Warning VSC - OBU-to-OBU - Instant (Problem) Messaging VSC - OBU-to-OBU - Blind Merge Warning VSC - OBU-to-OBU - Post-Crash Warning VSC - OBU-to-OBU - Merge Assistant VSC - OBU-to-OBU - Lane Change Assistant VSC - OBU-to-OBU - Left Turn Assistant VSC - OBU-to-OBU - Stop Sign Movement Assistant VSC - OBU-to-OBU - Cooperative Glare Reduction VSC - OBU-to-OBU - Blind Spot Warning VSC - OBU-to-OBU - Platooning VSC - OBU-to-OBU - Cooperative Adaptive Cruise Control VSC - OBU-to-RSU - Infrastructure-based Traffic Probes VSC - OBU-to-RSU - SOS Services VSC - OBU-to-RSU - Post-Crash Warning VSC - OBU-to-RSU - Just-in-Time Repair Notification VSC - OBU-to-RSU - Intelligent On-ramp Metering VSC - OBU-to-RSU - Intelligent Traffic Lights VSC - OBU-to-RSU - Blind Merge Warning Services defined for 5 GHz medium - 2

47. ISO TC204 ITS APPLICATIONS Service QoS Interface Selection Handover Interface QoS HTTP/ SMTP Protocols Stream & Realtime Protocols ISO DSRC L7 TCP UDP L2/UDP Init Hnd- ovr Secur MAC IPv6 layer 802.11p WAVE Init Hnd- ovr Secur MAC Init Hnd- ovr Secur MAC 2G/3G GSM GPS/Galileo CALM classic architecture …

48. SAP SAP SAP SAP SAP SAP SAP SAP SAP SAP ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21218 ISO 21214 IR Manager ISO 21215 W-LAN Manager ISO 21216 Millimeter Manager ISO 24xxx W-MAN Manager ISO 24xxx PAN Manager ISO 24xxx Wired Manager ISO 24xxx Broadcast Manager ISO 21212 ISO 21213 ISO 24103 2G Cell Manager 3G Cell Manager DSRC ISO15628 … GPRS EDGE … cdma2k UMTS … IR-B IR-A … WiFi M5 RADAR MM-J MM-E K-DSRC J-DSRC C-DSRC … HC-SDMA WiMAX … … Ether W-USB DAB AMIC BlueT CAN GPS CALM System Architecture (21217) (Rev. Geneva) Non-CALM-aware ISO 15628-based APPLICATIONS Non-CALM-aware IP (Internet) APPLICATIONS CALM-Aware APPLICATIONS CME Registration of Ingress/Egress Interfaces Application ManagementISO 24101 CME CALM Manager ISO 21210 SAP SAP SAP SAP SAP SAP Convergence Layer Part of ISO 15628ISO 21210 Convergence Layer IP socket/ISO 21210 TCP/UDP/… INTERNET STANDARDS SAP SAP SAP SAP SAP SAP NME Network Manager ISO 21210 NETWORK INTERFACE Routing and Media Switching based on IPv6 ISO 21210 SAP SAP IME Interface Manager ISO 24102 ISO 21218 SAP CALM Media External Media CALM Network 21218 = LSAP Applications Management SAP Data SAP SAP SAP

49. CME. Router Network Network Network NME. Router GPRSConvergence GPSConvergence DSRCConvergence IME. Router GPRS Stack DSRC L2/L7 GPS Stack GPRS PHY GPS PHY DSRC L1 Vehicle Architecture OEM G/W Real-time Applications CALMNetwork Layer C2CSwitch Layer Sensors, HMI and Control Firewall In-Vehicle App IVN DLL Ethernet IVN DLL RT Link IVN PHY Ethernet IVN PHY Ref pt In-vehicle OEM networks CAN/VAN/MOST/AMI-C.. ITS In-Vehicle Network 100baseT Ethernet Nomadic device Gateway Real-time Applications CVIS Integrated Mobile Router CALM Routing Comms gateway Network Network C2C-CC FastNet Ethernet CALM LLC CALM MAC Blue- tooth Blue- tooth Ethernet CALM M5 PHY Combined Antenna Pod

50. Communication Scenarios • CALM defines 5 communication scenarios: • 0 – V2I Non-IPv6 (WSMP or C2C-CC?) • 1 – V2I/V2V Local IPv6 • 2 – V2I MIPv6 • 3 – V2I NEMO • 4 – V2V Non-IPv6 (WSMP or C2C-CC?)