Developments in Transportation System Networks

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