VehicleVehicle, VehicleRoadside Communications Research supported by TO 4224, and gift from Daimler

1
Vehicle-Vehicle, Vehicle-Roadside
CommunicationsResearch supported by TO 4224,
and gift from Daimler Chrysler Research, Palo
Alto CA.PATH Conference, October 2002

• Raja Sengupta, Assistant Professor
• CEE Department, UC Berkeley
• Joint work with Ruchira Datta, Mustafa Ergen,
  Duke Lee, Tony Mak, Paul Xu, Marco Zennaro,
  Pravin Varaiya

2
Initial Research Target (1993)

• Wireless Networks for automated cooperative
  driving

3
Research Target

• Building wireless networks for advanced vehicle
  safety systems since 1995

4
Basic idea
5
Basic idea
Automated merge
Fits in 802.11 ad-hoc network paradigm
6
Our SolutionPATH Wireless Token Ring LAN
Protocol
T
Data
PS (C) B NS (C) A
C
T
Data
T
Data
B
PS (B) A NS (B) C
A
PS (A) C NS (A) B
7
SolutionPATH Wireless Token Ring LAN Protocol

• Orignially proposed by Varaiya and Foreman in
  1995
• Preliminary version built for merge demonstration
• Controllable deterministic access delays
• Bandwidth guarantees
• New version started in 1999, design ended in 2001
• Fully distributed, peer to peer
• Vehicles dynamically join and leave the network
• Robust to hidden terminals
• Trial implementation on top of UDP in the Teja
  high-level design language

8
Research Reports
9
Basic Operation
10
Performance Analysis
3 FTP Flow
Token Rotation Time
Rotation number
11
PerformanceThroughput comparison with 802.11

• 802.11 DCF
• No MAC level
• retransmission
• In WTRP

12
PATH Wireless Token Ring LAN Protocol

• Implementation and testing in 2001-2002
• Integrated into LINUX kernel with 802.11b driver
• Can be downloaded from the web and used for
  movies, internet browsing,
• Upgraded for use with new Orinoco gold radios

13
WTRP Driver level testing
Test parameters every station broadcast 100byte
of data every time it has a token
14
PATH Wireless Token Ring LAN ProtocolCurrent
Activities

• Required for Demo 2003
• Required for helicopter mesh flight demonstration
  in November 2002
• PC104 embedded version started working under
  LINUX last week
• To be used in PATH-ONR helicopter mesh
  demonstration
• QNX 4 version required for use in Demo 2003
• QNX 6.0 version on 5.9 GHz 802.11a radios
  required
• Adopted by ASTM with our recommendation as basis
  for the DSRC standard
• Requires a new driver
• Research collaboration with Atheros Inc. Palo
  Alto, CA
• Has provided existing drivers to PATH under NDA

15
Current ResearchTarget

• DSRC for cooperative vehicle information

16
Near Term
Not For me!
position speed intent

• DSRC for cooperative vehicle information

For me!
17
Near Term
Not For me!
position speed intent

• DSRC for cooperative vehicle information

For me!
18
Roadside Cooperation too

• Intersection testbed being built
• Roadside-Vehicle Communication research now being
  funded by IDS Consortium

19
The Broader DSRC Target
Transit Signal Priority
up to 1000 ft
Transit Vehicle Stop
Traffic Signal
Grass Divider
Collision Avoidance
E-Transaction gas, movie, .
Gas Pumps
IDB Data Transfer
Graphic created from Broady Cash (ARINC)
Not to Scale
20
The Broader DSRC Target

• Lots of people want to use DSRC
• Gas stations sell information, electronic gas
  transactions
• Public agencies transit/emergency signal
  pre-emption, electronic toll collection,
  commercial vehicle drive-by processing
• Fast food wireless transactions in the campus
• Automotive OEM VSCC consumer vehicle safety
• Collision warnings, cooperative safety
  information, intersection decision support, .
• Public agencies interested in these as well

21
In this mix, safety is the difficult one

• Current 802.11a radios tune to one channel at a
  time
• Safety messages may come from roadside assistants
  or from neighboring vehicles
• If the vehicle has one of the current radios and
  is using it to download movies while something
  screams obstacle in road, how does it get the
  message?
• The easy solutions
• It doesnt! Safety does not have priority.
• Problem If safety has no priority, why doesnt
  FCC auction the spectrum?
• The vehicle should have two radios, i.e., a
  safety and non-safety radio
• Problem Makes deployment harder. Hard enough to
  get one out there.
• The vehicle has one radio, it can be on any
  service channel, the service provider has to
  relay all the safety messages it hears
• Problem The service provider fails to relay, I
  have an accident, I sue!

22
Blend safety into a viable service package

• Safety should have priority
• This is a public interest. The spectrum should be
  free.
• The Shells, McDonalds, Blockbusters, should
  have licensed protection
• Gives them an incentive to invest in DSRC over
  the ISM band
• Electronic toll collection should be accommodated
• Big potential way of getting the radio into the
  car!
• The architecture should accommodate single or
  multiple radios
• Single radio ? some DSRC, Two radio ? more DSRC
  ?..

23
The ASTM DSRC architecture

• There is a control channel and many service
  channels
• Different services are licensed on different
  channels
• Make announcements on the control channel
• Vehicle stays by default on the control channel
• Our recommendation for initial deployment
• Put all vehicle-vehicle, roadside-vehicle
  communication for safety on the control channel
  as well
• Vehicle with single radio should receive most
  public safety messages when moving on public
  roadways
• ASTM concern
• Does this safety communication take up so much of
  the control channel that others cannot operate?

24
V-V Communication Requirements for Safety
Applications

• A first cut generated by Dr. H. Krishnan, GM
  Research

25
A first cut analysis
Failure rate requirement lt0.01
Feasible
Infeasible
7 14 21 28 35 42 49
56 63 70 Communication range (m)
26
First-cut analysis based on simple random process
model
27
DSRC may need a new intelligent broadcast protocol

• Situation aware
• Power control
• Broadcast rate
• Example
• High power on empty road
• Low power of congested road
• Open-loop compared to usual power control
• May be limited receiver feedback
• Requires fusion of radio with sensors

28
Channel occupancy for different Communication
Range
29
Channel occupancy for different Message Generate
Interval
30
Parameters and the maximum channel Occupancy
31
The Future

• A broadcast protocol for vehicle-vehicle,
  vehicle-roadside communication to enhance safety
• Design
• Repetition protocol considered
• Erasure coding protocol being examined
• Power control design in collaboration with
  collaboration with Daimler Chrysler Research,
  Palo Alto, CA
• Analysis
• First cut simple analysis completed
• Higher fidelity simulation analysis being
  conducted in collaboration with Daimler Chrysler
  Research, Palo Alto, CA
• Major difficulty No trustworthy model available
  for the vehicle-vehicle channel in ASTM selected
  technology

32
Looks promising Broadcast with erasure coding
Future
Done
33
The Future

• Applications
• Intersection warning
• Cooperative ACC
• Contribution to ASTM sponsored national DSRC
  architecture
• Leverage our decade long experience with
  vehicle-vehicle communications for safety

34
PATH DSRC Strategic Alliances for the future

• Sponsored projects
• Vehicle-vehicle communication
• CALTRANS, Office of Naval Research
• Roadside-vehicle communication
• IDS consortium funded by CALTRANS, FHWA
• Research collaborations with vehicle and wireless
  OEMs
• Daimler Chrysler Research, Palo Alto, CA
• General Motors Research, Warren, MI
• Atheros Inc., Palo Alto, CA
• New Vehicle Safety Communications Consortium,
  NHTSA-IVI
• Voting member ASTM DSRC standards committee