Download 1.7M PowerPoint Presentation

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)
•
•
•
•
Mobile IPv6 – RFC 3775 (2004)
•
•
•
•
•
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
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 Communications
EU-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 range
Defining protocols, management interfaces, interoperability, for V2V and V2I
communications over a variety of media