misled by opportunistic routing…

Posted by Jon Crowcroft

so one of the motivations that led me to think about all the Haggle stuff was the Milgram work. THis seemed to imply, as do pandemics, that a series of chance encounters could, over lots of iterations, provide end-to-end communications reliably.

10 years and 100 papers and algorithms later, it isn't looking so rosy - basically, pretty much every clever scheme has a delivery probability that is quite dismal, even if you set the lifetime of packets/bundles to be many days!

of course, we claim there are other reasons to build such a system (we always did - including reality mining style apps and serendipity)...

but the real problem is misunderstanding the result that Milgram got in his six-degrees work, which made use of the postal network - this isn't an opportunistic network - it is an unbelievably reliable aggregator and schedules delivery between pretty much anywhere on the planet mostly on a near daily basis. ANd the cunning people in the postal service historically provide us with a hint on how to apply this in opportunistic networking..

Indeed, if you go back to the distant past - read about Darwin's voyages on the Beagle (or, perhaps more fun, go see the movie Master and Commander) you'll see that any and all ships going around the world were tasked with the duty of delivering and picking up the post. Without deploying a specific scheduled post boat, instead, all boats going the right way were enlisted as the delivery channel.

Thus, instead of contacts between known friends/acquaintances being required in a successful chain, the weak ties are linked across distances by an early internet - but the early internet was, itself, spatially opportunistic (but "packets" were routed over it in aggregate sacks-worth to the right destination sets).

SO we need to build this (actually, back in Intel research cambridge days, I did propose putting a bluetooth device into the lining of all envelopes and postal bags as I guessed that people walking past the post room in each lab would "drop" and "pickup" their post via the bag, and that would achieve this miraculous shortcut that we've been looking for (without admitting defeat and going back to using the interweb:( )

So we need to data-mine people's use of google maps (i.e. equivalent of lifting their Satnav planned routes) and then use those people who've looked up a place (and maybe mentioned it in a tweet or other social media) to act as ferries (as per georgia tech term) Or mules, or, errr, unwitting act as the glue to get us back to the reliable delivery (sure, it still will involve physical travel rather than light-speed photonic networking, but it might get similar delivery properties as the Big-I Internet)

Time to build a simulation and try it based on some trace data....

Building pony express trade routes to strengthen weak ties, and regain the six degrees of separation!!


Live-blog from SenSys 2013 – Day 1

Posted by Aaron

The 11th ACM Conference on Embedded Networked Sensor Systems (SenSys 2013) just kicked off, held at the University of Rome 'La Sapienza' in Rome. From Cambridge, Cecilia is chairing the session "Sensing People" and the SenSys 2013 Doctoral Colloquium.

Some facts about SenSys 2013:

  • 250+ attendees
  • 1/3 are students
  • 40% have registered for both the conference and the workshops

For submission:

  • 21 papers got accepted out of 123 submissions (17%)
  • most of them received 3 to 8 reviews
  • 70 presentations in the poster and demo track - each one also got a 1-min madness talk during the main conference

There is an interesting opening talk by the chairs showing some stats about the submission this year (as far as I can recall)

  • register the paper earlier, and submit it late (close to the DL) - this holds for most of the accepted ones
  • most of the accepted papers are from America, around 50%
  • certain key words in the title will lead to rejection: nodes, networking, vehicle, etc. (I should have taken a photo while laughing at that slide.. :(

Since there is no electro-plug in the conference room. Most of notes are on the paper. Will find time to move them here.

Keynote by Shahram Izadi from MSR Cambridge: "The New Face of the User Interface"

Introduce the work carried out at MSR Cambridge by the Human-Computer-Interaction (HCI) group, including the 3D interaction of physical and digital objects, 3D model reconstruction using smartphones (using the Queens' College and the Mathematics bridge in the demo). They highlight how to design using low price component and smartphones.

Session 1 - Communication Systems

Chaos: Versatile and Efficient All-to-All Data Sharing and In-Network Processing at Scale

Olaf Landsiedel (Chalmers University of Technology, Sweden), Federico Ferrari (ETH Zurich, Switzerland), Marco Zimmerling (ETH Zurich, Switzerland)

Q: Mainly evaluated by simulation, will it be a gap if the design is applied to real environment?

A: Not yet tested in real environment, hence we don't know.

Let the Tree Bloom: Scalable Opportunistic Routing with ORPL

Simon Duquennoy (SICS Swedish ICT AB, Sweden), Olaf Landsiedel (Chalmers University of Technology, Sweden), Thiemo Voigt (SICS Swedish ICT AB and Uppsala University, Sweden)

Practical Error Correction for Resource-Constrained Wireless Networks: Unlocking the Full Power of the CRC

Travis Mandel (University of Washington), Jens Mache (Lewis & Clark College)

Use CRC to correct wireless transmission errors, solving the reliable issue by their design TVA, Transmit-Verify-Ack.

Very good presentation, and presenter ends his talk with a song about CRC :)

Session 2 - Sensing People

iSleep: Unobtrusive Sleep Quality Monitoring using Smartphones

Tian Hao (Michigan State University), Guoliang Xing (Michigan State University), Gang Zhou (College of William and Mary)

Using sound monitoring to infer sleeping quality.

Lifestreams: a modular sense-making toolset for identifying important patterns from everyday life

Cheng-Kang Hsieh (UCLA CSD), Hongsuda Tangmunarunkit (UCLA CSD), Faisal Alquaddoomi (UCLA CSD), John Jenkins (Cornell Tech), Jinha Kang (UCLA CSD), Cameron Ketcham (Cornell Tech), Brent Longstaff (UCLA CSD), Joshua Selsky (Cornell Tech), Betta Dawson (UCLA CSD), Dallas Swendeman (UCLA David Geffen School of Medicine Department of Psychiatry and Biobehavioral Sciences), Deborah Estrin (Cornell Tech), Nithya Ramanathan (UCLA CSD)

Probably the longest author list in SenSys history.

14GB data collected for 44 young mothers.

Q: How do you recruit patients?

A: Done by the partners in hospital.

Q: Any new findings from the data?

A: We detect some hidden behaviors not noticed by the patients, e.g., unusual long walking outdoors, due to anxiety.

Diary: From GPS Signals to a Text-Searchable Diary

Dan Feldman (MIT), Andrew Sugaya (MIT), Cynthia Sung (MIT), Daniela Rus (MIT)


Live-blog from SOSP 2013 – Day 2

Posted by Ionel Gog

The second day of the 24th ACM Symposium on Operating Systems Principles has just started.  Several of us are here and will be live-blogging the talks and Q&A sessions.


Posted by aa535

Not even two weeks since IMC pass and we have the first citation of our RilAnalyzer paper! However, the paper has quite a few inaccuracies. I will not try to enumerate all the inaccuracies (one could easily do that by looking at our paper and comparing), but will outline a few.

Filed under: Rants Continue reading

Live-blog from SOSP 2013

Posted by Malte Schwarzkopf

The 24th ACM Symposium on Operating Systems Principles is about to kick off in beautiful Nemacolin Woodlands this morning. Several of us are here and will be live-blogging the talks and Q&A sessions. We've got exciting papers on multi-core scalability, fast transactions, synchronization and many other topics coming up, and that is just the first session!