1. A New Ph.D. Program in Computational Transportation Science Ouri Wolfson University of Illinois, Chicago
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2. Talk outline Computational Transportation Science cytuc Mobi-dik
Data Dissemination
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3. Background for Computational Transportation Science
Problem: Real-time information to traveler has not changed much in 40 years
Objective: Enable dramatic improvement of the travel experience – based on information
Idea: Capitalize on the wireless personal communication tidal wave to revolutionize transportation
Approach: Architecture and software platform for the development of novel transportation applications
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4. Information Technology
New Ph.D. program
Information Technology
Transportation
Funded by the National Science Foundation, $3M.
UIC match: $2.5M
Will train about 30 Scientists
Researchers from 12 academic departments, 6 colleges
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7. Main differences from other transportation centers
Focus on:
Computer Science and IT
Traveler rather than vehicular technology
Applications above communication layer
Education component
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8. Wireless P2P data management
cytuc
Computational Transportation Science
Mobi-dik
Data Dissemination
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9. Mobile Local Search: applications
social networking (wearable website)
Personal profile of interest at a convention
Singles matchmaking
Games
Reminder
Messaging (SMS)
mobile electronic commerce
Sale on an item of interest at mall
Music-file exchange
transportation
Announce sudden stop, malfunctioning brake light
Announce patch of ice discovered by abs
Search close-by taxi customer, parking slot, ride-share
emergency response
Search for victims in a rubble
asset management and tracking
Sensors on containers exchange security information => remote checkpoints
mobile collaborative work
tourist and location-based-services
Closest ATM
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10. Environment
Pda’s, cell-phones, sensors, hotspots, vehicles, with wireless
capabilities
A central server does not necessarily exist
resource-query C
resource-query B
resource 4
resource 5
resource 8
resource-query A
resource 1
resource 2
resource 3
Local query
Local database
Resources of interest
in a limited geographic area
possibly for short time duration
Applications coexist
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11. Technical Approach
Use emerging short range wireless communication over unlicensed spectrum
Completely decentralized peer-to-peer solution – save centralized solution cost
802.11
802.11, bluetooth -- unlicensed spectrum
cellular
Alternate network selection depending of Information Type
Cellular  Point-to-point by net-id
Short-range  Geospatial/anonymous/location-based
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12. MP2P: Why now? Revisit paradigm:
“devices should be small, so put intelligence in infrastructure”
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13. Research Problems in Mobile P2P
Data modeling –
many simultaneous applications,
sensor- and human-generated information
Resource management (bandwidth, power, memory)
Participation incentives for brokers,
to achieve reasonable search coverage
Dynamic and adaptive use of fixed infrastructure
Managing Heterogeneity
Remote Querying
Privacy, security, HCI
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14. Focus of Mobi-dik Information ranking Ranking done by aggregating
demand,
temporal,
spatial,
novelty,
reliability
factors pertaining to data items
Aggregation uses machine learning techniques
Independent of the network (b/t or wifi)
Consequences of ranking:
improved search
The important (most likely to be useful) information is saved and communicated
improved memory, bandwidth, power utilization
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15. Focus of Mobi-dik (cont.)
Bandwidth and Power management by dynamic adaptation of
Size of each transmission
Frequency of transmissions
Range of each transmission
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16. Talk outline Computational Transportation Science cytuc Mobi-dik
Data Dissemination
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17. Application
Capture (discovery) of competitive (on/off) physical resources
Competitive resource: at most one consumer a time (parking slot, cab-customer, cab)
Compare
discovery time without information
discovery time with information (clearly shorter, enables seeing around block)
Conveyed in MP2P fashion
With ranking
Without ranking
Conveyed by ideal client server
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18. Outline of rest of talk
Peer-to-peer Broadcast (PPB) – a bandwidth-sensitive MP2P algorithm
Comparison with Searching-without-Information and Ideal-central-server
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19. Resource report Resource type (parking slot) Transmission time
Location of resource
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20. Mobile P2P Broadcast
Resources periodically send reports to moving objects that pass within transmission range.
Moving objects periodically sort the reports according to their relevance and broadcast the top M reports.
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21. Elements of PPB Relevance function Broadcast period
Broadcast size (number of reports in a broadcast)
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22. Relevance Function Theorem: Assume:
(1) Consumers arrive at R according to a Poisson process with intensity .
(2) The average speed of the consumer is v.
(3) A report R is generated at location (0,0) and at time 0.
Then: for a consumer that receives a(R) at time t and distance d from (0,0) , the probability that the resource R is still available when the consumer reaches R is
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23. Power of relevance function
Broadcast size = 1
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24. 802.11 Throughput (Effective bandwidth)
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25. Relationship: Broadcast size to Broadcast period
Expected throughput of the wireless channel in an (802.11) ad-hoc network
Broadcast period depends on density, transmission range, size of broadcast, and is chosen to maximize E(Th)
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26. Outline Peer-to-peer Broadcast (PPB)
Comparison with Ideal-central-server
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27. Comparison with Ideal Dissemination (Central-server)
In ideal dissemination, a report is immediately transmitted to all vehicles after it is generated by the resource.
With very reasonable broker density (average inter-broker distance of 173 meters) and wireless transmission range (250 meters), the performance of the PPB reaches that of the ideal dissemination case.
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28. Relevant research work
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29. Mp2p vs. client-server Mp2p advantages Mp2p disadvantages Zero cost
Unregulated communication
No central database to maintain
Independent of infrastructure
Higher reliability
Privacy preservation
Mp2p disadvantages
Weaker answer-completeness guarantees
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30. Relationship to work on Mobile Ad Hoc Networks
Work mainly concerned with sending a message to an ip-address
In contrast, MP2P focuses on dissemination among a group interested peers
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31. Resource Discovery in MANET
A MANET routing protocol is augmented to enable addressing based on resource type or resource key rather than network ID B A
A’s routing table C
Resource type
Next hop
printer
music
restaurant C D B
Ip address
Next hop
1234
2345
3456 C D B D
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32. Construction and Maintenance of Routing Table
Printer?
Resource type
Next hop
printer B
Printer?
Here! A B
Here!
Problems when applied to our context:
Does not work when consumer and resource are disconnected.
Resources are transient. Consumer has to constantly poll.
Constructed routing structure easily becomes obsolete.
May take awhile to construct in Bluetooth networks
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33. Other relevant work Manet’s bandwidth capacity
Power management in Manet’s
Data broadcasting
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34. Mp2p vs. sensor networks
Devices more powerful and reliable than sensors
Sensor network topology mostly static
Aggregate function computation vs.
trigger firing
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35. Experimental MP2P projects (Pedestrians)
7DS -- Columbia University (web pages)
iClouds – Darmstadt Univ. (incentives)
MoGATU – UMBC (specialized query processing, e.g., collaborative joins)
PeopleNet -- NUS, IIS-Bangalore (Mobile commerce, information type  location baazar)
MoB – Wisconsin, Cambridge (incentives, information resources e.g. bandwidth)
Mobi-Dik – Univ. of Illinois, Chicago (brokering, physical resources, bandwidth/memory/power management)
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36. Vehicular projects
Inter-vehicle Communication and Intelligent Transportation:
CarTALK 2000 is a European project
VICS (The Vehicle Information and Control System) is a government-sponsored system in Japan with an 11-year track record
FleetNet, an inter-vehicle communications system, is being developed by a consortium of private companies and universities in Germany
IVI (Intelligent Vehicle Initiative) and VII (Vehicle Infrastructure Integration), the US DOT
MP2P provides data management capabilities on top of these communication systems
Grassroots – Rutgers, p2p dissemination of traffic info to reduce travel times
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37. Conclusion -- IGERT New Ph.D. program:
Computer Science + Transportation Science
Novel applications:
Traffic Management
Traveler services
Emergency response
Research Themes:
Information Management and Communication
Software Services
Human Factors
Intelligent Traveler Assistant
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38. Conclusion - Mobidik Innovative aspects: Performance comparison with
Information Ranking
Memory, Power, Bandwidth management
Performance comparison with
Flooding
Ideal central server
Blind search
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