Transcript CMU/GM Collaborative Research Lab Interference

CMU/GM Collaborative Research Lab
Wireless Broadband Access for the
Automobile: Applications and Enabling
Technologies
Dan Stancil
Acknowledgements: Ratish Punnoose,
Stanley Wang, Richard Tseng, He Huang,
James Casazza, James Grace, Jessica Hess,
Kevin Borries, Jacob Meyers, Tony Nolla,
Priya Narasimhan, Ed Schlesinger
Jay Parikh
July 29, 2003
CMU/GM Collaborative Research Lab
Outline
• Where we’ve been
• Where we’re going
CMU/GM Collaborative Research Lab
Wireless Networking: Where
We’ve Been
• Understanding
– Interference between Bluetooth and 802.11b characterized
– Basic understanding of noise from small number of interferers established
(Ph.D. thesis)
– Coverage of 2.4 GHz signals within a vehicle for different antenna
placements
• Infrastructure
– Communications Resource Management using CORBA middleware:
• Scalable, flexible architecture proposed
• Demo of interactions between cellphone agent, CD player agent, speech
agent, and sound agent (Video demo available)
CMU/GM Collaborative Research Lab
Co-existence in Unlicensed
Bands
• A number of wireless technologies are in use
in the unlicensed bands.
– 802.11, Bluetooth, ITS services, many proprietary point-topoint wireless connections.
• Future wireless technologies are likely to use
the ISM bands.
– No need for licenses, rather wide bandwidth, worldwide
availability, decreases time to market.
CMU/GM Collaborative Research Lab
Interference
• These wireless devices share the frequency
spectrum.
• Operation of devices interferes with the working of
other devices using the same band.
• Effects can be seen as:
– Reduced data rate.
– Increased error rate.
– And sometimes, a failure to operate.
• Exact behavior of co-existing devices is not wellcharacterized.
CMU/GM Collaborative Research Lab
BT Interference on 802.11b
Rx
BT
Laptop
Tx
Power
Splitter
802.11b Tx
ATT
Laptop
Attenuator
Rx
VAR
ATT
ATT
ATT
802.11b Rx
Variable
Attenuator
-6dB
Isolator
BT
Laptop
Laptop
Tx
Directional
Coupler
CMU/GM Collaborative Research Lab
Performance of 802.11b with
Bluetooth Interference
% lost packets
Signal strength =-61dBm
20
11 Mbps
15
10
5
0
-55
-50
-45
-40
-35
-30
-25
-20
-25
-20
Signal strength =-61dBm
% lost packets
60
2 Mbps
40
20
0
-55
-50
-45
-40
-35
S/I in dB
-30
CMU/GM Collaborative Research Lab
Theory for 802.11/Bluetooth
Interference
802.11 Packet
Bluetooth Packet
Frequency
Time
CMU/GM Collaborative Research Lab
Noise Distribution
• The noise values have a
probability distribution.
CMU/GM Collaborative Research Lab
PDF of Gaussian Noise +
Interference
CMU/GM Collaborative Research Lab
In-vehicle Communication
• Vehicle will likely participate in local 2.4 GHz
networks with personal electronic devices
– Bluetooth
– Wi-Fi
• Unobtrusive antennas are needed that can be
camouflaged
• Optimum antenna placement decreases
power and reduces interference to other
electronics
– Useful to know the propagation coverage within the vehicle
CMU/GM Collaborative Research Lab
Test Vehicle Setup
• Pontiac Montana
• Transmitting antenna placed on dashboard and
ceiling
• Empty vehicle, and with driver
Dash
Ceiling
CMU/GM Collaborative Research Lab
Effect Of People
• Obstruction by the driver or other passengers
CMU/GM Collaborative Research Lab
Results Showing Effect of
Driver
Dash location without driver
-25
Dash location and driver present
-30
-30
150
-35
100
-40
50
-45
0
-50
Front of Car (cm)
Front of Car (cm)
150
-25
-35
100
-40
50
-45
0
-50
-55
0
100
200
Side of Car (cm)
0
300
-60
dB loss
100
200
Side of Car (cm)
300
-55
-60
CMU/GM Collaborative Research Lab
Communication Components of CMU/GM
Vehicle Testbed
Palm/PDA
Speakers
PDA Cradle
USB
Controller
Jog Dial/
Mouse Wheel
USB Controller
Finger Print
Recognition
Firewire
Controller
Digital
Camera
Microphone
WaveLAN
Sound Card
CellPhone
USB Controller
Firewire
Controller
Radio Card
TV Card
EtherNet
Serial
Controller
Vehicle’s ECU
- RPM, MPH, etc
Serial
Controller
GPS Receiver
CDPD
Modem
Acknowledgement: Asim Smailagic, Dan Sieworek,
Rapid Prototyping Class (Fall 2001)
VGA Controller
Touch Screen
Temperature
Sensor
CMU/GM Collaborative Research Lab
Communication System
Architecture Goals
• Provide support for different data service
requirements.
• A manager to arbitrate resources.
• Provide easy access to commonly used
functions (eg. GPS)
• Provide a framework for building software
agents that have to interact with each other.
• Minimal change to existing applications.
CMU/GM Collaborative Research Lab
Software Interaction using
CORBA
Traffic going to the
outside
CORBA Interface
Direct Interaction
Event Distribution
Internet Access
Channels
Per-link QOS
information
Proximity
Alert
Fuel
Sensor
Route
Planner
QOS based
Data Routing
GPS
ITS/
Emergency
Info
Communications
Resource Manager
Publisher/Subscriber Transport using
the CORBA Event Service
TV, AM, FM, DAB,
Cellular Call
Request
CMU/GM Collaborative Research Lab
Demo Video
CMU/GM Collaborative Research Lab
Middleware Comparisons
Client
CORBA
TAO/C++
CORBA
Java IDL
OSGi
Mean: 163
SD:
6.5
Mean: 796.0
SD:
638.0
Mean: 12.5
SD:
110.0
Server
CORBA
TAO/C++
CORBA
Java IDL
OSGi
Mean: 45700.5
J2EE
SD:
18750.5
J2EE
CMU/GM Collaborative Research Lab
Where We’re Going
• Understanding
– Peer-to-peer propagation channel at 2.4 GHz and 5-6 GHz
• Infrastructure
– Van experimental infrastructure update
– Peer-to-peer wireless links using technologies such as Bluetooth and
802.11a,b,g
– Middleware testbed for agent and communication resource architecture
and management
– Intelligent mobile IP client
• Applications
– DSRC
– Short-range transactions
– Real-time traffic information
CMU/GM Collaborative Research Lab
Experimental Van: Before & After
Original infrastructure
Updated infrastructure
CMU/GM Collaborative Research Lab
Peer-to-Peer Networking
• Exchange of emergency/traffic information
• “Walkie-talkie” style communication between
vehicles
• Allow one vehicle to function as a network
portal for nearby vehicles
• Exchange of diagnostic information
• Facilitate platoon formation for efficient
highway travel
CMU/GM Collaborative Research Lab
Peer-to-Peer Testbed
• Collect extensive propagation data between
vehicle pairs using different frequencies and
technologies
– 802.11b, 802.11a, UWB
• Enable demonstrations of application
concepts
• Results will facilitate selection of most
promising technologies
• Provide GM with background to influence
evolving standards
CMU/GM Collaborative Research Lab
Vehicle Mobility in the Internet
• A vehicle may have a different Internet address for
each network attachment point.
• This allows it to access Internet servers but it is not
easily accessible due to changing IP addresses.
• The vehicle needs to be accessed for diagnostics
and status information.
• Mobile IP provides seemingly continuous Internet
access to its Mobile Hosts by obtaining an IP address
from its Home Agent.
• With Mobile IP each vehicle can be addressed using
a single IP address, regardless of the point of
connection.
CMU/GM Collaborative Research Lab
Mobile IP Design
.
Application
Basic Entities:
MN = Mobile Node
HA = Home Agent
FA = Foreign Agent
CH = Correspondent Node
TCP/UDP
IP (routing)
CN
Home Network
HA
Foreign Network
FA
MN
CMU/GM Collaborative Research Lab
Advantages of MoIP
• Transparency
– Continue using its home address.
– Ability to communicate after disconnect & reconnect.
– Change its point of attachment.
• Compatibility
– Support of any lower layer that IP runs on.
– No change to ordinary hosts and routers.
– Communicate with unaware nodes.
CMU/GM Collaborative Research Lab
Birdstep Intelligent Mobile IP Client
• Allows seamless roaming between networks without
having to restart VPN session!
• Presently being installed at CMU
Note: FA only required under certain circumstances, such as NAT traversal
CMU/GM Collaborative Research Lab
Proposal: Traffic Companion
• Pittsburgh has an extensive network of traffic
condition sensors
• Mobility Technologies, Inc.
(http://www.mobilitytechnologies.com) is
commercializing this technology
• http://www.traffic.com/Pittsburgh/index.html
• PennDOT has an extensive network of traffic
cameras
• http://www.epenndot.com/traffic_cams.php#
CMU/GM Collaborative Research Lab
Traffic.com map
•
http://www.traffic.com/Pittsburgh/index.html
Map
updated
every
minute
CMU/GM Collaborative Research Lab
PennDOT Traffic Cam Images
• Images updated every minute
http://www.epenndot.com/traffic_cams.php#
CMU/GM Collaborative Research Lab
Could we put access to this in
the vehicle?
• Connectivity via Verizon 1X wireless data +
hotspot roaming
• Real-time traffic conditions
• Just-in-time route planning
• Using cyclic patterns to predict best route
• Useful but non-distracting graphical interface
CMU/GM Collaborative Research Lab
Summary
• Past Projects
– Unlicensed coexistence
– Communications Resource Management using Middleware
– 2.4 GHz propagation coverage in and around vehicle
• Future Directions
– Peer-to-peer test bed
• Propagation channel
• Middleware architecture
– Mobile IP Intelligent client for seamless roaming
– CMU Traffic Companion for real-time traffic planning
CMU/GM Collaborative Research Lab
For More Information
•
•
•
•
•
•
•
“Interference Between Devices in the ISM Band.” - Ratish
Punnoos/Dan Stancil
“Antenna Placement in Vehicles: Electromagnetic Propagation at 2.4
GHz.” - James Casazza, James Grace, Ratish Punnoose, Dan
Stancil
“Communications Resource Management for Advanced Telematics
Applications.” -Richard Tseng, Ratish Punnoose, Stanley Wang,
Dan Stancil, Ed Schlesinger
Communications Resource Manager Video- Stanley Wang
“Interoperability, Performance Evaluation and Adaptation of CORBA,
OSGi and J2EE for Telematics Applications.” - He Huang, Ratish
Punnoose, Priya Narasimhan, Dan Stancil
“Peer-to-Peer Unlicensed Communication Between Automobiles.” James Casazza/James Grace
“Wireless Broadband Access for the Automobile: Applications and
Enabling Technologies.” - James Casazza/James Grace