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Experiments with User-Centric
Ad-hoc Applications
Durga Prasad PandeyMIT Media LabJuly 31st 2007
Presented at:IBM Watson Research Center
Cambridge
~FluidVoice~an infrastructure-less
voice conferencing system
Wouldn’t it be cool if I could listen to everyone in the lab?
Maybe not!
Who’s playing loudmusic at work?
Only Grace has the temerity to do that!
Actually, its D u r g a !!
Oops! ;)
Circle of influence, or ‘speak if you dare’
Grace
Kwan
Durga
Robots Affects
Andy
David
You’ve been FluidVoiced!!
9
Mann last night at the nightclub..psst psst…
Hey dude! What did I just say? Isn’t FluidVoice on?
It is!!!
My reach? Its everywhere!•
What is FluidVoice?• A conferencing system• No infrastructure• Push to listen• Ad-hoc• Wireless• A viral system
Why Voice?• Heavy enough to stress the wireless
network and reveal weaknesses– Video can buffer, sensors don’t send much data
• Time sensitive• Its an application!
13
Compelling Application?• 5000,000 Children’s Laptops(OLPC)• Mesh Networking enabled• Huge potential of on the fly voice
collaboration• Testbed and Usebed
14
Architecture
15
What’s viral?• Start small• Scalable• Incremental. Each node adds value.• Examples: Skype, Google, eBay, Napster..
Why does it matter?• Better characterize the wireless space• Cynic: But wireless is unreliable, bad bla
bla…– Well let me build a system, learn from it, fix it.
• Exploit inherent broadcast nature– Wireless is not a link
• Collaborate on the fly!
Traditional Telephony
18
A C
FluidVoice-Many2Many
19
C
Technically speaking• Broadcast UDP packets• Mixer locally, not like Yahoo chat!• Gateway allows calls from cellphone/PSTN• Neat Interface borrowed from Sociable
Media work• More than 9 nodes = system starts getting
ill• Built on VIA boards = Free trip to LA!
Whats hot!• Nodes running in offices• Demo on N800• Gateways to PSTN/cellphones and Avaya
p2p phones• Web based UI• Separation of UI, mixing and listening
22
To Sum Up• Privacy - someone’s hearing me!• Local mixing - everyone has a mixer.• Identity - who’s allowed?• Inversion of the telephone system -
– Traditional: Point to Point– FV: Many to Many with Point to Point as
special case
• Philosophy - Open the communications space to innovation. 23
Future Work• FluidVoice on N80 Nokia Cellphones• Deployment of FluidVoice in the Media Lab
building• Deployment of a credit based multihop
system in FluidVoice• Separate multiple conversations
24
UniPlug:A Framework For Ad-hoc Invention sharing
Invention
• Computer programs/software
• Diagrams
• New applications
• Websites
• Video tutorials
• Online Papers
What’s the problem?
• Invention sharing is currently not ad-hoc
• Need to be able to build systems that allow a community to share inventions
• There are lots of inventions on the MIT campus that are forgotten
• If I plug my iPod into the laptop, can I get all the programs people have written for it?
What UniPlug does
• Ad-hoc sharing
• Plug-n-Play detection of devices
• Proximity detection of Bluetooth devices
• Automatic lookup and download for useful software from UniServer
• User populated UniServer
Requirements
• Work well in Ad-hoc environment
• Populatable in a distributed way
• Code should be trusted or verifiable. Malicious users must be punished.
• System should be scalable
Architecture
• UniClient
• UniServer
• OpenDHT
Mechanisms
• Leader election for LANs
• Inter-UniServer borrowing
• Store only whats relevant locally
• Context-oriented programming
Leader election
• Every LAN has a leader that responds to requests for service discovery
• Leader can be chosen round robin or credit system based
• Leaders signal to others when they are about to relinquish
• No heartbeat means leader is no more
Local content
• Store inventions only for devices that are registered for the community
• Look for content for those registered devices periodically from other UniServers with frequency specified by users
• Credit based serving of number of requests
Models
• Peer-to-Peer
• InterLibrary
• Client-Server
Context Classification
• User Context(BP)
• Device Context(battery level)
• Surroundings Context(# of wifi networks)
Scaling
• System scales by having lots of users host content
• Scaling only needed for the campus
• Everyone hosts content they need and service others only on interlibrary.
• A machine will only perform a limited number of services.
Demo: UniPhone
Demo: UniBlue
UniBlue for Fluidvoice
Security Issues
• Trust networks for small communities
• Human moderated invention posting
• Damage control for malicious code released
Patient-centric UniPlug implementation scenario
Medical Devices PnP
• MGH based consortium
• Value in interconnecting Medical Devices
• Currently they aren’t interoperable across vendors
• Doctors’/BioMed engineers’ inventions need to be sharable
• Context-oriented programming will be critical
To Sum Up
• Context-based invention sharing
• Better device utilization
• Inventions not lost over time
• Enables better collaboration
Future Work
• Demo with medical devices and OR of the future
• Full P2P version of UniClient
• Deployment and testing with the MIT community under Living The Future program
Questions?
• Thanks!
• Special thanks to Daniel Gruen and Ciaran Dellafera.