[IAEP] The value of plastic
I found his approach to teaching children about plastic/oil interesting. http://motherboard.tv/2010/8/22/a-machine-that-turns-plastic-back-into-oil--2 ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
[IAEP] Mesh Dreams = OLSR
Where Mesh != 802.11s but rather an adhoc, self healing, self organizing routable network. Imagine a world where Sugar on a Stick machines can communicate on the same network as an XO laptop. A world where mesh capabilities are hardware agnostic allowing anyone to bring up a mesh network by booting a live cd. Imagine a school full of XOs where some are connected to Adhoc Channel 1, some to Channel 6, and some to Channel 11. Now think of an XO that has two USB Wireless Adapters each connected respectively to one of those channels. This central XO also has a third USB ethernet dongle or a 3G wireless modem attached to it. Consider how this simple setup could provide Internet to everyone in the school. Consider the ability to actually create Mesh Portal Points, that allow one connection to provide an Internet connection to many hops down the line. Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. These things are all almost immediately possible by using OLSRd software. Over the past few months, I have tested and built small networks around my neighborhood to consider the feasibility of such software. Now I realize there is a difference between small and large networks but I think it is something we should consider. As I have said, please *consider * all of these things with a fresh perspective and try to forget about the prior mesh battles. Let's think of solutions that will actually make this work. Some things to consider from Aaron Kaplan, a member of the OLSR community, cc'd here: How to scale networks? -The key is to have multiple channels, smart channel selection/ assignment, automatic txpower control and low interference between nodes! -In a sense, it is funny but true: the quieter the devices become, the better everybody can hear his mesh partner. -Summary: layer 2 is king for scalability , only then do you need to look at layer 3 optimizations (and with OLSR.org we already took care of that part I hope that we can come together to re-group and re-think how we OLPC and SugarLabs do connectivity and utilize the open opportunities available to create such solutions. Regards, Reuben ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
[IAEP] Stamp $50 Android tablet prototype raises eyebrows in India and beyond (video)
Just another future possibility... http://www.engadget.com/2010/08/23/stamp-50-android-tablet-prototype-raises-eyebrows-in-india-and/ ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
Hi Reuben, Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. The fact that a custom mesh algorithm would have to run on the CPU -- prohibiting any kind of idle-suspend -- makes it a non-starter for an XO deployment in my eyes. Did you have any thoughts on this? - Chris. -- Chris Ball c...@laptop.org One Laptop Per Child ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 10:26 AM, Chris Ball wrote: The fact that a custom mesh algorithm would have to run on the CPU -- prohibiting any kind of idle-suspend -- makes it a non-starter for an XO deployment in my eyes. Did you have any thoughts on this? Hi Chris, Great point. Thank you for bringing this up. I have given this some thought; though I'm curious to know if this is your only objection to the suggestion? I find it interesting that what you consider a non- starter, I consider a feature. I have often considered it a bit presumptuous for us to deplete one child's precious power resources to maintain the mesh network for other children. We have created a model where in essence one household is funding access to the Internet in another household through power costs. My thoughts are: we don't do this. If the XO wants to go into idle-suspend let it. The connecting XO will have to find another path or lose access to the Internet. Either way it is a better solution then what we have now. If children group together and knowingly disable idle-suspend so they can maintain a mesh network for their neighbors then that is fine and a great example of building community but doing so as a mandatory implementation IMHO and with all due respect is questionable. Some things I'd like to point out. -8.2.1 has idle-suspend disabled by default and we are considering disabling by default idle-suspend for new XO - 1 builds. In these cases OLSR would be performing fine. -The switch in WLAN chip from XO 1.0 to 1.5 forces us to re-think how we do connectivity. -The thin-firmware being built for XO 1.5 has the same CPU-prohibiting idle-suspend limitation and *does not* include a user base and support community of thousands of users and active development. Yet it relies on one closed source firmware developed by one firm based on the same mesh technology developed 3 years ago. It also lacks my hardware agnostic points. -On the XO 1.5 builds where idle-suspend is working (CONGRATULATIONS TEAM), I'd recommend letting it idle-suspend. Yes, it will create route-flapping but in the school scenarios there should be enough paths to maintain connectivity and in the household environment any bit more of connectivity is better then none. It also leaves children and families the ability to knowingly disable-idle suspend and provide a resource to their neighbors. Thank you for your thoughts. Reuben ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 5:24 PM, Richard A. Smith wrote: On 08/24/2010 10:13 AM, Reuben K. Caron wrote: Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. The largest of our mesh problems did not have to do with scalability on sheer number of nodes but rather scalability in density. Is there any information available on how these networks perform when there are 50 - 100 of them next all in the same room or in adjacent rooms? Yes! And the answer is very very simple: turn down the txpower! ;-))) best regards, Aaron (OE1SYS) PGP.sig Description: This is a digitally signed message part ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 11:24 AM, Richard A. Smith wrote: On 08/24/2010 10:13 AM, Reuben K. Caron wrote: Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. The largest of our mesh problems did not have to do with scalability on sheer number of nodes but rather scalability in density. Is there any information available on how these networks perform when there are 50 - 100 of them next all in the same room or in adjacent rooms? In those scenarios we run into RF density issues even when using APs. From what I understand, OLSR has a better mechanism for maintaining the mesh information. If you recall any change in mesh was previously broadcasted to all listeners. OLSR is configurable. For instance, information would only be broadcasted to two levels of one devices immediate neighbor not the whole mesh cloud. Another issue we had was maintaining mesh information in a limited memory space on the WLAN module; OLSR would now process that information. ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 5:24 PM, Richard A. Smith wrote: On 08/24/2010 10:13 AM, Reuben K. Caron wrote: Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. The largest of our mesh problems did not have to do with scalability on sheer number of nodes but BTW Richard, as far as I remember the problems with 802.11s seemed to be: 1) the standard is not a standard and it was intentionally crippled 2) the drivers were very b0rked and broken (and Marvel did a terrible job with the driver software) Scalability to less than 30 laptops in one room was the result. A standard good AP and standard laptops can go to 30 in one room (with standard settings). So, there was definitely something broken with the Marvel solution. Fix layer 2 first, then look at layer 3. PS: can you forward my answer to the lists? I am not subscribed... PGP.sig Description: This is a digitally signed message part ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
The largest of our mesh problems did not have to do with scalability on sheer number of nodes but rather scalability in density. Is there any information available on how these networks perform when there are 50 - 100 of them next all in the same room or in adjacent rooms? Yes! And the answer is very very simple: turn down the txpower! ;-))) Can you provide me with a pointer to the numbers? Whats the maximum number of nodes can you have operated in a given area and what sort of network traffic tests did you run? Well, the community wireless networks are not very much about very dense settings. We try to cover large areas with external (outdoor) antennas but still have very many nodes in one single mesh covering a whole city or so. See the attached current map of the Funkfeuer.at network. BUT!! Because we don't have a mesh with 100s of laptops in one room, does not mean, we don't know physics ;-) Since you asked if I know an example where there are many laptops in one room: One example that I know that worked brilliantly well with many wireless devices in one room was the RIPE meeting in Amsterdam. There they regularly have many small APs below the desks in the meeting room and these are turned down very much in volume (txpower). The effect is that they only cover a small area ( remember, power decreases by the square of the distance). So this is a way to avoid a lot of noise of many laptops in a small room. Another feature that you IMHO should look at is 802.11n devices (and of course also turn down the volume there!). These offer higher bandwidths in addition to actually using the multipath effects. When you have many many laptops in one room and everybody screams/sends very loud then you have lots of echos (multipath fading) bouncing off the walls etc. 802.11n thrives off these multipath effects. As I said - first solve layer 1 2 issues and then think about layer 3 meshing. I hope I could help. Best regards, L. Aaron Kaplan (OE1SYS) PS: please forward my answers to the list or allow me to post to the list. I am not subscribed there . Thx. PGP.sig Description: This is a digitally signed message part ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 12:08 PM, Richard A. Smith wrote: I'm not talking about comparison to our previous mesh. Thanks keeping me on track. I'm talking about comparison to an AP. Overall we currently don't have much need for mesh as most of our scenarios are a dense cloud of children in the same space trying to network with each other. Fo deployments that have funding for APs there is not much need for mesh. I would approximate that roughly 66% of our user base are in deployments that do not have funding for APs. The network-without-infra feature of mesh is certainly useful in scenarios were you want to provide access over a wider area. Its a very important feature of mesh but its just not the feature we need on the ground ATM. Yet, this is a feature, we continue to sell and a feature often requested. However, if the same mesh smartness also gets density without using AP's then that's a big win. Agreed! Reuben ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
(...) BTW Richard, as far as I remember the problems with 802.11s seemed to be: 1) the standard is not a standard and it was intentionally crippled 2) the drivers were very b0rked and broken (and Marvel did a terrible job with the driver software) Scalability to less than 30 laptops in one room was the result. A standard good AP and standard laptops can go to 30 in one room (with standard settings). So, there was definitely something broken with the Marvel solution. Fix layer 2 first, then look at layer 3. Yes, Yes, I'm not trying to defend the previous mesh implementation in any way. Pretend the previous OLPC mesh does not exist. And in fact on a XO 1.5 it does not exist. OK. Didn't know. I'm saying that the bulk of our rollouts are dense scenarios connected to an AP. If we can do better density than an AP with less equipment then thats something to go for. yes, you can - take the RIPE example: just reduce the txpower and have multiple APs. There are also some very smart APs with a central controlling AP out there (Cisco has some of those). These APs balance out the clients magically. If you can't do better than an AP then unless you are doing the minimal-infra wide area part of mesh there isn't much in it that will help the bulk of OLPC rollouts. Well - the issue is IMHO that OLPC always sold the public on the mesh idea. So it is somewhat of a bummer that the mesh is gone now. I might add that the Funkfeuer/Freifunk -style outdoor meshes are still another totally cool option: you can mesh the different schools this way very cheaply. So that is another thing to consider IMHO. PS: can you forward my answer to the lists? I am not subscribed... Sure but I'm not on iaep so I can't help there. thx! PGP.sig Description: This is a digitally signed message part ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Tuesday, August 24, 2010 11:26:23 am Chris Ball wrote: Hi Reuben, Consider the benefits of using open source software versus our closed source firmware and partnering with communities like Freifunk whose network is ~ 800 node, guifi.net is almost 10k nodes in Barcelona, Athens Wireless is 5k nodes. The fact that a custom mesh algorithm would have to run on the CPU -- prohibiting any kind of idle-suspend -- makes it a non-starter for an XO deployment in my eyes. Did you have any thoughts on this? We (MontevideoLibre, a free wireless community network) have been using OLSR for a while now. And though the topology in a typical OLPC scenario is very different, we've talked about assembling an image running OLSRd for a while. Anyway, I dont have time for a full response to this thread right now, but I had a conversation with smithbone and silbe a while back that may be illustrative of the worse-case scenario in terms of power consumption: aasilbe: I think a working PoC could gather a lot interest from deployments... silbe aa: one thing to consider is the power draw. with libertas_tf, the host CPU needs to be powered on. aayes aasilbe: do you have an idea of what that means in actual numbers? aaperhaps smithbone has a guesstimate silbe aa: counter-question: are you thinking of running the protocol while the XO is powered off (screen off, everything in suspend with wake-on-WLAN) or just during regular operation? silbe for the latter case, it might not make much of a difference, especially if automatic power management (automatic suspend) is disabled. smithbone Running the system is going to cost you in the 5W range. silbe in the powered off case it's going to make a huge difference. I don't think it'll be able to run for more than 3h while there's any traffic. aasilbe: one of the things I want to find out is the convergence time of the different options silbe aa: i.e. the time until the network/mesh is stable? aayes silbe aa: if you were in europe, you might try getting funding from the EU for that ;) aasilbe: also, BATMAN has a layer 2 kernel module, maybe we could make it aware of the PM state? silbe they seem to pay some pretty sums for mesh research * aa migrates to Europe aa:P silbe aa: it should just integrate into the kernel PM QoS framework I cuppose, see Documentation/power/pm_qos_interface.txt aasilbe: will do silbe aa: oh, and some recent mail from me has a link to nice slides explaining the PM QoS framework aasilbe, smithbone: do you guys know if wol would work with libertas_tf? aasilbe: to sugar-devel? silbe aa: no idea, sorry. silbe aa: I think to de...@l.l.o aasilbe: found it, thanks! smithbone aa: which gen? aasmithbone: XO-1 smithbone aa: on XO-1 the wakeup is generated by strobing a signal to the EC. So libertas_tf would need to support strobing that signal aasmithbone: thanks a lot, is this documented somewhere? aatoo bad the firmware is closed :( smithbone aa: no. because none of the systems you are talking about have open documentation aasmithbone: I understand smithbone aa: But I can certainly tell someone what gpio on the wlan module to strobe and for how long. -- -Andrés signature.asc Description: This is a digitally signed message part. ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 11:24 AM, Richard A. Smith wrote: The largest of our mesh problems did not have to do with scalability on sheer number of nodes but rather scalability in density. Is there any information available on how these networks perform when there are 50 - 100 of them next all in the same room or in adjacent rooms? Here is a link to a paper that actually tested in a physical 49 node lab with various configurations: http://dev.laptop.org/~reuben/Elsevier2008_OLSR_compare.pdf This differs from most other papers that I have read that use theoretical simulations. Reuben ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
Re: [IAEP] Mesh Dreams = OLSR
On Aug 24, 2010, at 7:11 PM, Reuben K. Caron wrote:
On Aug 24, 2010, at 11:24 AM, Richard A. Smith wrote:
The largest of our mesh problems did not have to do with scalability on
sheer number of nodes but rather scalability in density. Is there any
information available on how these networks perform when there are 50 - 100
of them next all in the same room or in adjacent rooms?
Here is a link to a paper that actually tested in a physical 49 node lab with
various configurations:
http://dev.laptop.org/~reuben/Elsevier2008_OLSR_compare.pdf
This differs from most other papers that I have read that use theoretical
simulations.
Yes, IMHO you *need* the real world simulations (and even then it is very easy
to make measurement mistakes and arrive at arbitrary conclusions [1]). I
started to only trust big real world deployments.
Thanks for the link, still have to read it in detail. BTW: the conclusion
section of this paper already confirms our previous discussion about reducing
txpower: Currently hop counts up to 5 are achievable with routing protocols in
the full 7x7 grid when the power is set to 0dBm with 30 dB attenuators.
;-)
a.
[1] @ARTICLE{Kurkowski05manetsimulation,
author = {Stuart Kurkowski and Tracy Camp and Michael Colagrosso},
title = {Manet simulation studies: The incredibles},
journal = {ACM SIGMOBILE Mobile Computing and Communications Review},
year = {2005},
volume = {9},
pages = {50--61}
}
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.110.7902rep=rep1type=pdf
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Re: [IAEP] [SLOBS] meeting minutes
Am 24.08.2010 13:32, schrieb Walter Bender: One topic only touched upon briefly was the need for a Sugar Camp. We have two offers of venues: Bolzano the week of November 6 and Miami during a time to be determined. If you would be interested in attending a Sugar camp sometime in the November/early December time frame, please contact me and also, if you have a preference of venue, please voice it. I'm definitely up for another Sugar Camp, it's been too long since Sugar Camp Paris (since I unfortunately missed the last one in Bolzano). In terms of timing be advised that some of the people who might be interested in attending Sugar Camp will just come out of the grand meeting that OLPC-SF is organizing in late October. So that first week of November might be a bit too close for some of them. Anyway, I'll keep a close eye on this and hope to be able to make it to the Camp if indeed takes place in Europe:-) Cheers, Christoph -- Christoph Derndorfer co-editor, www.olpcnews.com e-mail: christ...@olpcnews.com ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
[IAEP] Sugar Camp
Walter Bender wrote: One topic only touched upon briefly was the need for a Sugar Camp. We have two offers of venues: Bolzano the week of November 6 and Miami during a time to be determined. If you would be interested in attending a Sugar camp sometime in the November/early December time frame, please contact me and also, if you have a preference of venue, please voice it. Oct 21/22 - 24 in San Francisco makes the most sense to me, given it will be the largest gathering of OLPC/Sugar/Realness implementors ever: (well over 30 RSVP'd so far, from 4+ continents, even before broad announcement!) http://olpcsf.org/CommunitySummit2010 Sameer Verma who arranged great hosting with SF State Univ here says we can accommodate 100 people. Mike Lee's been working hard on beautiful artistic announcements appearing here shortly, eg: http://flickr.com/photos/curiouslee The barcamp-style agenda already shows great Edu, Tech, Depl Outreach tracks, growing fast after we all promote this in coming weeks :) http://wiki.laptop.org/go/OLPC_SanFranciscoBayArea/OLPCSF_Community_Summit_2010#Possible_Topics In fact those volunteers who've been working hard putting this together have drawn heavily upon prior Sugar/XO/Realness Camps and Book Sprints, eg: http://wiki.sugarlabs.org/go/Marketing_Team/Events/MiniCamp_Paris_2009 May 2009 http://wiki.laptop.org/go/ClassActs Sep 2009 http://wiki.sugarlabs.org/go/Marketing_Team/Events/Sugarcamp_Bolzano_2009 Nov 2009 http://wiki.laptop.org/go/OLPC_SanFranciscoBayArea/OLPCSF_Community_Summit_2009 Nov 2009 http://realness.org May/June 2010 The group is considering a very small (perhaps $30) charge to help with T Shirts and potentially some partial funding of travel scholarships for those from outside North America. Not yet finalized, but remote access will also be strongly encouraged. Plz join the Very Awesome volunteer organizers here if you can!! http://lists.laptop.org/listinfo/olpc-sf ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
[IAEP] Congratulations OLPC-Peru!
OLPC-Peru is one of the 2010 WISE (World Innovation Summit for Education) finalists. Information about this summit and other finalists can be found here: http://www.wise-qatar.org/en/2010-finalists Congratulations! ___ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep
