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Developments in Transportation System Networks

Explore the developments in transportation system networks, including intelligent transportation systems (ITS) and vehicle communications, which aim to reduce congestion and improve safety in road transport. Learn about the advancements in technology, such as variable-message signs, traffic light control systems, and vehicle-to-vehicle/vehicle-to-infrastructure communications.

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Developments in Transportation System Networks

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  1. Developments in Transportation System Networks November 2009

  2. Intelligent Transport Systems (ITS) • Term generally applied to technology used to reduce congestion and improve safety in transport – most often road transport • Not a new idea – has been around since 1960s • Variable-message signs in use since 1960s • SCATS, SCOOT, TRAC traffic light control developed in 1970s (and still in use today) • Intelligent transport society of America founded in 1991 • Intelligent transportation systems given radio spectrum spot by FCC in 1999 – Dedicated Short Range Communication (DSRC)

  3. Convergence onto IP/Ethernet • During the 2000s, the elements of ITS have amalgamated onto a single communication system for • CCTV • VoIP • Variable sign control • On-ramp metering • Toll-booth systems • Microwave vehicle detection systems • Even bridge movement detection

  4. Active traffic management • Integrated data and coordinated access to signs/controls enables the following actions dynamically in response to conditions • Speed control • Route control • Quickly clearing traffic out of lanes • Opening outer lane • Turning on-ramp controls on/off

  5. Next step - Communicate with the vehicle • Current methods communicate with the driver • Aimed mostly at congestion reduction • Now the scope is broadening to take in safety • To make serious safety gains, it is necessary to communicate with the vehicle • Machines can react more quickly than people

  6. Vehicle communications • Vehicle to Vehicle (V2V) • vehicles to be informed of braking action of vehicles in front • vehicles warn oncoming traffic of icy patches. • emergency vehicles alert other vehicles of their approach • awareness of vehicles in ‘blind spot’ • Vehicle to Infrastructure (V2I) • infotainment • Navigation • Internet Access

  7. Vehicle communications

  8. The Car as a LAN • Low-speed data buses between electronic components being replaced by ethernet • Driven by software upload times in repair shops • Ethernet-connected entertainment devices installed • Ethernet for external communication

  9. Mobile IP evolution • Mobile IPv4 – RFC 2002 (1996) • Defined Mobile Node, Home Agent, Foreign Agent, Home Address, Care-of Address • Mobile node’s data tunnelled between Foreign Agent and Home Agent • Protocol details refined in later RFCs • Mobile IPv6 – RFC 3775 (2004) • No need for foreign agent • No IP-in-IP encapsulation – uses IPv6 extension headers • Supports ‘route optimization’ – direct communication no via home network • Uses inherent security headers • IPv6 provides superior mobility solution to IPv4

  10. Mobile IP evolution cont. • NEMO – RFC 3963 (2005) • Mobility for whole subnets, not just individual hosts – hence NEtwork MObility • Does not support route optimization • Does support nesting of mobile subnets • Suitable protocol for the V2I communication of In-car LANs

  11. NEMO – problems to be solved • Handover latency • Acquiring new address in new foreign network • Re-establishing connection with home agent • Routing inefficiency and Extension header overheads • Required to communicate via home network • Extreme case – aeroplane moving a network 1000s of miles • Need to introduce route optimization • IPSec overheads • Move to certificate-based key negotiation

  12. Layer-1 and Layer-2 communications • IEEE 802.11 Task Group p has developed 802.11p – known as Wireless Access in Vehicular Environments (WAVE) • Supports rapidly changing environment • Provides fast connection establishment • No need to agree on SSID, just use a wildcard • Uses DSRC spectrum • Developed with road safety applications as primary goal • Acceptance that carrying commercial services required to speed uptake

  13. VANETs • Vehicular ad-hoc Networks • Groups of vehicles forming adhoc connections using 802.11p • V2V and V2I connections

  14. Geographic routing - GeoNet • Geographic routing applied specifically to VANETs • Uses the geographic position and movement information of vehicles to route data packets. • Each node maintains a location table including location related information for itself and a list of its neighbouring nodes. • Position information, including speed and direction, exchanged in beacon packets • Forwarding uses Greedy Perimeter Stateless Routing (GPSR) protocol

  15. GeoNet cont. • Communication modes: • GeoUnicast – from a node to a known location • GeoAnyCast – from a node to any node in a geographic area • GeoBroadCast – from a node to all nodes in a geographic area • Topo-Broadcast – from a node to all nodes a given number of hops away

  16. GeoNet protocol stack

  17. Security challenge • Inter-vehicle communications must be secure • Hackers could cause severe problems • Communication relayed through intermediate vehicles requires privacy • But very challenging environment for security • Require fast inter-vehicle connection establishment • Vehicles must collaborate to forward traffic • Very little knowledge of neighbouring nodes • Not guaranteed access to PKI certificate authorities

  18. Privacy • If vehicles are too easily identified, they can be tracked, for malign purposes • Need to use multiple certificates, and swap between certificates at random intervals • Need to generate multiple IPv6 addresses, and swap between certificates at random intervals

  19. Active bodies • C2C-CC – Car to Car Communication Consortium • non-profit organisation initiated by six European car manufacturers aiming to develop a open industrial standard for inter-vehicle communication • CVIS – Cooperative Vehicle Infrastructure Systems • consortium of 60 vehicle and parts manufacturers, universities, research institutes, national road administrations. To develop standards and components for V2V and V2I communications • SeVeCom – Secure Vehiclar Communications • EU-funded project that focuses on providing a full definition and implementation of security requirements for vehicular communications.

  20. Active bodies – cont. • JARI - Japan Automobile Research Institute • IETF, ETSI, ITU, IEEE, ISO, etc • ISO working Group – CALM – Continuous Air-Interface Long and Medium range • Defining protocols, management interfaces, interoperability, for V2V and V2I communications over a variety of media

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