Sunday, September 23, 2007

royal society meeting on transport/network modeling

so monday/tuesday next week, I am at the Royal Society at a meeting (and giving a
talk on tuesday- viz:
transport and net modeling

radio 4 had a nice programme about this event where a coupel of guys I work with,
Frank Kelly in cambridge and Andrew Odlyzko in the US, talk quite well (in terms
of good public explanation of tricky stuff in plain english)

if you do podcasts, here it is:
at the material world

my talk on mobility and forwarding elicted some interesting questions on location versus co-location based models (from RIchard Gibbens), and on distributed computation over DTNs (from Brad Karp) (see Rondini's work at UCL).

Most talks were from either transport viewpoint, or communications modeling viewpoint, but most speakers made more than a token effort to explain the applicability of their work to the "other" side - one of the talks on analysing MIDAS road monitoring data (richard gibbens) was very illuminating.

One idea I had was to implement "packet drop" on roads - this can be done one of two ways:- 1/ deflection routing - force people off the optimal (e.g. in shortest path sense) route if it is congested 2/ force people to park - on freeway, this could be done in lieu of a toll - time is money - so if you implement individiaul charges (tolls), or you have pay as you drive insurance, you could increase the "charge" for a given speed til enough people slowed down to get throughput back up - if this is done coupled with averaging speed cameras (e.g. M1 now), then it can be enforced too and would possibly entail a fraction of people pulling over and stopping for a while to "get their cost" down...

Tim Griffin game a nice exposition of how Inter-domain routing works, and how it could be better modelled - this is clearly directly applicable to road and other transport systems since it entails understanding that local optimisation only is necessary for systems that are competing (ratehr than global optimisation that you might get for a monopoly or state provided single monolithic transport system) _ so "joined up thinking on transport" might involve running BGP between road, rail, air, bus, taxi etc as a way to find multi-modal routes:)

More generally, one question arose about the common ethical problems (e.g. privacy) between both transport and communication networks, for example, even just doing experimental work gathering traces of users activities, you can data mine to infer a LOT even without knowing content of car/packet!

BBC reports BT still don't beleive case for fiber to the home which is amusing given Andrew Odlyzko's talk...and 11M japanese homes already have it..oh well...

meanwhile, I am mostly just reading through this year's syllabus for GCSE science, and am pleased to say that while there is a lot of material about touchy feely things like ethics, global warming, GM crops, there is still a clear indication that real science teachers had a say in the content as there is quite clearly a section on "making fireworks" that will let budding chemists blow things up (my favourite bit!). actually there's some good stuff on electricity and periodic table and on waves/light etc, so I dont think its too shoddy.

Saturday, September 22, 2007

"and so" & "once again" those cliches and obsolete metaphors

so travelling to Nice last 2 days I notice CS people start all talks and interrupts with "and so" and all airline staff start all announcements with "once again"
and I notice many obsolete metaphors (pictures of old cameras with bellows for godsakes to n=indicate surveillance - pictures of phones or the word "dial", and talk about records and "spining" - kids will be very confused

so was I as I read Alex James auto-bio - "A bit of a blur" back to back with alastair campbell's "the blair year" diaries - it was fairly hard to see who had the bigger ego or was more out of touch with reality...

Tuesday, September 18, 2007

sleepwalking into the cyber-surveillance society

Cory Doctorow writes
yet again, a very perceptive piece on how we dont need DARPA's total awareness project to have very bad things happen in the online world!!!

read it and weep...

Sunday, September 16, 2007

good tech journalism...

I was very happy to read this article in the telegraph about why
IT's still cool to be a computer expert by wendy grossman - we had a long phone conversation about a lot of stuff a week before, and it looks like it captures the key points and removes all the irrleavnt stuff I said, plus the quotes fro mother folks I know seem well chosen - I hope it has some positive impact!

Wednesday, September 12, 2007

OLPC news with ears on

So jim getty's did a nice talk on this here monday -see
john naughton's summary - I think the key thing for me (pun intended) is that the machines ship "locked" and seperately. a key is delivered to enable them- and if the machiens are nicked, they can be revoked! this is to stop corrupt interception in some parts of the world - another interesting point came up - what if an older brother tries to sell their sibling's? aswer: the older brother will have one too , as will all households (saturation bombing) in a region

finally, I asked about mesh/p2p voice - bizarrely, on the bbc news site, later that day we get
the news about TerraNet free p2p voice - maybe they should use haggle:)

Jim also recommends you read
hree Cups of Tea: One Man's Mission to Promote Peace . . . One School at a Time" by
Greg Mortenson;

Tuesday, September 11, 2007

out of touch...?

it wasamusing to see several US folks at SIGCOMM in Kyoto with very large, expensive
mp3 playeres they'd bought from Apple, which allegedly are some kind of phone - only don't work outside of US GSM coverage:-) My guess is that the iPhone will largely only sell in the US until they a) unlock it b) allow 3rd party apps to run on it and, last but not least c) put a 3G chip/radio in it so it actually works in the 21st century like other products one can already buy in EU and APAC for less (with more battery life), but makes a change

Sunday, September 02, 2007

Today at KAIST in Daejeon, Korea - Workshop ReportTrip Report - Late August/Early Sep 2007, Japan & Korea

Trip Report - Late August/Early Sep 2007, Japan & Korea

I've put my comments on the CCR feedback site for
this years SIGCOMM papers, so this is my trip report
for the Kyoto part of the trip and you can get papers fom here too:

Also see Pan Hui's SIGCOMM Mobiarch workshop paper.


my talk:
H0: what if use haggle fwd for synch comms?
(compare to MANET (dongman lee,, asks) - proactive, reactive, location based)
KAIST results show can always do better!

H1: how to control storage needs of DO for forwarding:
Me: have to implement forgetting (cache), and assume DOs within community for
community relevance has good locality

Mia's talk: chris anderson, "The Long Tail"
(based on IMC student award paper)

Yangwoo Ko - late binding and use of
app. info for deciding how/when/who to forward
definitely haggle relevant!
SGR addresses H0, above!
next steps: use name service (NO/DO like)

Bodizar Radunovic, MC2!
so what do you do about lost tokens (e.g. nodes leave system) or new nodes?
plus do you have any ideas how to stop fake credit tokens?
for one idea (near end) on how to deal with churn...

Levy walk nature of human mobility and its impact on DTN/MANET performance"
Kyunghan Lee (KAIST)
has some very large (well 50+ node) measurement using fine grain GPS, then does
model fitting - shows truncated heavy tail (Levy) is good for people, better than Brownian, but also RWP and Levy yield same gain in forwarding, so
also haggle relevant! - concludes: shows DTN is MANET with higher delay,
but higher throughput! very nice!
see also
Andrew Edwards, who gave a talk at MSR while ago about the albatrosses
experiment in Antarctica, is now in Canada. Nature paper (to appear in next 8 weeks)
shows it isnt a good model after all!

"On the Optimal Resource Allocation in Multi-hop Wireless Networks"
Hyang-Won Lee
and this one too!
capacity as resource, but interference is simple model


"R-BGP: Staying Connected in a Connected World"
Bruce Maggs, as per NSDI paper - jolly good.

"Lessons learnt from large scale P2P systems and how they apply to the Future Internet"
Pablo Rodriguez, ex Inktomi, MSR-C and now at TIS (telefonica's new lab in Barcelona)
now: P2P from an ISP (and telco)'s perspective... ... ...message: its useful, not just for piracy.
But 2 key problems:- interference between P2P overlay traffic demand, and underlying TE and
peering/customer provider relationships between ISPs. Point of view is that there wasn't a way to bill for
ip multicast multiplier, but there might be a way to bill for p2p = by volume.

Note: sender gets money by number of recipients of content.
If use 1-1, easy - if do multicast, get a log cost.
if do P2P, get log net cost and reduced sender/storage costs.
log cost means you need a recursive tree charge based on sub tree.
reduced data center cost is just too bad for CDNs:) - one point about p2p v. multicast:-
p2p requires end user to increase symmetry of uplink -
you don't really need to charge by volume precisely - you could charge by time the uplink is full -
the end user could have this offset against content charge made by the content provider - value chain is
1. telco charges source for attachment rate
2. if net does packet copy, each branch point gets charged by telco for number of branches, recursively
3. leaves get to pay this charge, and have it subtracted from content lehal/drm fee

2bis: if leave does p2p, uplink, they get charged by net
3bis but get it discounted against content fee (since the uplink means that
they've succesfully re-sold content to some other receivers who are
paying for content but not for net yet


rest of talk on ip multicast tv - as per recent work

ed Power-Delay Tradeoff in Wireless Ad Hoc Networks Using Opportunistic Routing"
Won-Yong Shin (KAIST) - info theory analysis to find the advantage of fading in opprtunistic networks,
of getting capacity greater than the gupta/kumar model (e.g. from diversity) - excellent stuff! basically seems
to show that the Tse 2007 idea happens for free in a DTN...assumes only CSI available only at receiver:-
Opportunistic routing based on Biswas&Morris - packet proceeds to next hop closest to receiver; so change this to send and chosenext tx in next microcell to be any node with valid reception - gives diversity thru randomness - gain is ln(N) for N nodes per cell.

"Study on network size estimation schemes for peer-to-peer networks"
Hosik Cho (Seoul National University): reminds me of one of the microsoft research things
done by richard black and austen donnelly to do network discovery (think its in vista now)+and (sue moon points out) also multicast group size estimation.

"Spamscatter: Characterizing Internet Scam Hosting Infrastructure"
Geoff Voelker

All good talks - very active and very timely research, and good awareness of current hot topics and techniques to tackle them!