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!!

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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!

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Compelling Application?• 5000,000 Children’s Laptops(OLPC)• Mesh Networking enabled• Huge potential of on the fly voice

collaboration• Testbed and Usebed

14

Architecture

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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

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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

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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

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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.