Developments in Transportation System Networks

November 2009

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)

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

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

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

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

Vehicle communications

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

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

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

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

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

VANETs

• Vehicular ad-hoc Networks

• Groups of vehicles forming adhoc connections using 802.11p

• V2V and V2I connections

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

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

GeoNet protocol stack

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

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

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 CommunicationsEU-funded project that focuses on providing a full definition and implementation of security requirements for vehicular communications.

Active bodies – cont.

JARI - Japan Automobile Research Institute

IETF, ETSI, ITU, IEEE, ISO, etc

ISO working Group – CALM – Continuous Air-Interface Long and Medium rangeDefining protocols, management interfaces, interoperability, for V2V and V2I communications over a variety of media