6'964 Pervasive Computing ContextAware Networking

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6.964 Pervasive ComputingContext-Aware Networking

• Stephen J. Garland
• October 4, 2001
• MIT Laboratory for Computer Science
• Networks Mobile Systems
• http//nms.lcs.mit.edu/

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Networks Mobile Systems

• Faculty
• Hari Balakrishnan, John Guttag
• Research staff
• Stephen Garland, Dorothy Curtis
• Students
• Omar Aftab, David Andersen, Magda Balazinska,
• Deepak Bansal, Nick Feamster, Jason Gift, Greg
  Harfst,
• Karin Iancu, Kyle Jamieson, Jaeyon Jung, Kalpak
  Kothari,
• Nikos Michalakis, Ronnie Misra, Allen Miu, Todd
  Nightingale,
• Bodhi Priyantha, Jon Salz, Ali Shoeb, Alex
  Snoeren,
• Zeeshan Syed, Godfrey Tan

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Demonstration
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Ingredients of Demonstration

• Resource discovery

• Context-aware applications

• Nomadic, adaptive mobility

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Context-Aware Networking

• Resource discovery
• Name resources by what they do, not where they
  are
• Intentional Naming System (INS)
• Location discovery
• Adapt operation to current location
• Cricket location-support system
• Not just in space
• Nomadic, adaptive mobility
• Switch among multiple networks
• Migrate application-controlled end-to-end mobile
  routing
• Adjust to current network conditions, application
  needs
• SpectrumWare software-based digital signal
  processing

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Resource Discovery

• Services advertise/register resources
• Consumers issue queries for services
• System matches services and consumers
• Really a naming problem
• Attach names to services
• Treat queries as name resolution requests
• Problem most of todays naming systems name by
  (network) locations
• Names should refer to what, not where

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Intentional Names

• Expressive name language (like XML)
• Service providers announce attributes
• Clients issue queries
• Attribute-value matches
• Wildcard matches
• Ranges

service mit.edu/camera building NE43 room
510 resolution800x600 access
public status ready
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INS Architecture
camera510.lcs.mit.edu
Lookup
image
Resolver self-configuration

• Overlay network of
• intentional name resolvers

Late binding integrate resolution and message
routing
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Location Discovery

• Recognize spaces, not just physical position
• Good boundary detection is important
• Operate inside buildings
• GPS only operates out of doors
• Preserve user privacy
• Help users discover location without tracking
  them
• Minimize administration, deployment costs
• Decentralized architecture and control
• Low cost and power consumption

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Traditional Approach
Location DB
ID u ?
Networked Sensor Grid
ID u !
Responder
Problems privacy administration granularity
cost
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Cricket Approach
Listener
Beacons
Infer nearest space a1

• No central beacon control, location database
• Privacy from passive listeners, active beacons
• Straightforward deployment