Hacker News: shaddi

New comment by shaddi in "Endaga – Community Cellular Networks"

shaddi — Mon, 08 Dec 2014 01:59:41 +0000

We don't support roaming yet, so phones from other carriers won't work on our networks. The networks are fully independent, with their own phone numbers and connectivity to the global phone network though.

Definitely get in touch if you'd like to talk more! Many of our customers live in places that sound like where you live.

New comment by shaddi in "Endaga – Community Cellular Networks"

shaddi — Mon, 08 Dec 2014 01:49:19 +0000

Basically this. Spectrum regulations (both de facto and de jure) vary dramatically between jurisdictions. It's definitely a challenge, but not as big of a deal as one might expect, particularly for rural networks.

New comment by shaddi in "Endaga – Community Cellular Networks"

shaddi — Sun, 07 Dec 2014 22:20:10 +0000

Our current model retails for $6,000. It's an exciting time to be working in this space -- five years ago, setting up a single tower in a rural location could cost upwards of $100,000.

New comment by shaddi in "Endaga – Community Cellular Networks"

shaddi — Sun, 07 Dec 2014 22:13:47 +0000

Cofounder here. All service is prepaid, and we have a credit transfer system built-in. The network operator can load up credits onto someone's account directly through our management interface, and that user can resell it to whoever they like. For example, a network operator could sell credits in bulk directly to shop owners, who could then resell to the community at large.

Endaga Brings Rural Villages Online With a Cell Network in a Box

shaddi — Mon, 01 Dec 2014 19:53:46 +0000

Article URL: http://recode.net/2014/12/01/endaga-brings-rural-villages-online-with-a-cell-network-in-a-box/

Comments URL: https://news.ycombinator.com/item?id=8683292

Points: 9

# Comments: 1

New comment by shaddi in "Mesh Networks"

shaddi — Mon, 26 Aug 2013 06:28:34 +0000

It seems like there's been another surge of interest of late in mesh networks. Last time this happened, I wrote up a piece explaining why mesh networks are really a poor solution for circumventing censorship: http://sha.ddih.org/2011/11/26/why-wireless-mesh-networks-wo.... Since then, some of my colleagues and I at Berkeley wrote a more academic version of this blog post. The talk is available here: http://www.youtube.com/watch?v=doMYDmtzsTQ and you can grab the paper too if you're interested: http://www.cs.berkeley.edu/~shaddi/papers/foci13.pdf. The short version is mesh networks have fundamental scaling limitations that make them a poor choice for building alternative infrastructures like the ones discussed in this article; for example, a result from 2000 showed that capacity available to each node in a mesh network actually decreases as the mesh grows.

The other thing I'd note is that this article is referring to "mesh networks", when it really means "community networks": networks run by a community, regardless of whether the network is a mesh or not. I don't know about the Athens network in particular, but I know that the Freifunk and Guifi networks are rather hierarchically structured (i.e., are not true mesh networks). This is necessary for building a wireless network with reasonable performance due to the aforementioned fundamental scaling limitations of mesh networks.

I love the enthusiasm of everyone working on mesh networks, but I think it's valuable to keep a critical perspective and not get carried away with that enthusiasm, if for no other reason than to stay honest about the technical challenges involved.

New comment by shaddi in "Turning the Raspberry Pi Into an FM Transmitter"

shaddi — Wed, 23 Jan 2013 16:23:55 +0000

I have this sitting on my desk at the moment (just OpenBTS + rPi + a SDR). Nothing too crazy about it.

I like this because they are using the rPi itself as a radio -- that's a pretty neat hack.

New comment by shaddi in "What's Wrong with Amazon's DynamoDB Pricing?"

shaddi — Mon, 05 Mar 2012 17:47:30 +0000

To be fair, they're not explicitly charging twice as much for consistent reads. You get consistent reads until you exceed your provisioned read amount, which unfortunately is measured in these odd units of "read capacity"). It's not clear (to me, anyway) if the 2x number represents something accurate about resource usage or if it's just a provisioning guideline.

That said, what provisioned capacity means in DynamoDB is pretty opaque. Great point about the utility of latency information for developers.

New comment by shaddi in "Why wireless mesh networks won’t save us from censorship"

shaddi — Sun, 27 Nov 2011 17:58:08 +0000

I'm less worried about this actually -- I think the biggest problem is your own nodes interfering with themselves ("internal interference") rather than with an attacker. Agreed this is an issue though, and using omnidirectional antennas exacerbates it. Using directional antennas actually helps, for the same reason it's hard to see a laser beam from the side.

New comment by shaddi in "Why wireless mesh networks won’t save us from censorship"

shaddi — Sun, 27 Nov 2011 07:09:40 +0000

Even an electronically steerable antenna would help, but then you start running up the cost of equipment. Interference is still an issue since one must always be listening from all directions for possible transmissions. Spectrum and time scheduling remain a (NP-)hard problem as well. You're up against fundamental laws of physics and computer science: pick your poison. :)

New comment by shaddi in "Why wireless mesh networks won’t save us from censorship"

shaddi — Sun, 27 Nov 2011 07:05:53 +0000

I generally agree, but I tried to shed some light on the fundamental physics/math behind why building such a network is impractical. In any case, it might one day be possible, but I think a better use of resources (especially for non- and semi-technical people) is to contribute to the social movement around Internet free speech and to build real-world political networks.

Why wireless mesh networks won’t save us from censorship

shaddi — Sun, 27 Nov 2011 04:31:34 +0000

Article URL: http://sha.ddih.org/2011/11/26/why-wireless-mesh-networks-wont-save-us-from-censorship/

Comments URL: https://news.ycombinator.com/item?id=3281697

Points: 104

# Comments: 34

New comment by shaddi in "Show HN: We built Callroulette, a chatroulette for phones"

shaddi — Fri, 12 Aug 2011 03:00:26 +0000

Yeah, that's the tricky part. It took a couple revisions in front of users to figure out the right way to do bootstrapping.

Show HN: We built Callroulette, a chatroulette for phones

shaddi — Fri, 12 Aug 2011 01:22:23 +0000

Article URL: http://tier.cs.berkeley.edu/callroulette

Comments URL: https://news.ycombinator.com/item?id=2875570

Points: 76

# Comments: 29

New comment by shaddi in "Show HN: Callroulette, a chatroulette-like service for phones"

shaddi — Tue, 09 Aug 2011 03:38:09 +0000

We need to get a dozen or so simultaneous users for it to work nicely. Please be patient! I'm seeing several users calling in right now.

Edit: we've made some changes to greatly increase the likelihood of matching with someone!

Show HN: Callroulette, a chatroulette-like service for phones

shaddi — Tue, 09 Aug 2011 03:32:04 +0000

Article URL: http://tier.cs.berkeley.edu/callroulette/

Comments URL: https://news.ycombinator.com/item?id=2862780

Points: 14

# Comments: 2

New comment by shaddi in "The Politically Incorrect Guide to Ending Poverty"

shaddi — Fri, 04 Mar 2011 02:18:15 +0000

Excellent point -- no simple solutions. It's why this is a hard problem.

New comment by shaddi in "The Politically Incorrect Guide to Ending Poverty"

shaddi — Fri, 04 Mar 2011 01:50:31 +0000

Once again, I don't dispute that; we're in full agreement. My key point is that the effects of liberalism that lead to growth in Hong Kong did not lead directly to growth in rural China; as nice as that would be, there were other forces at play that caused that. Another way of putting this is to say that the effect of the communist government was to constrain growth around Hong Kong, and infrastructure development occurred in rural areas despite that.

The motivation behind "charter cities" is exactly that such a direct effect from liberalization would occur, whereas that doesn't necessarily follow and certainly not well-illustrated by the article's example. It is just one point in a broader criticism of the whole concept: such cities may provide an example, but they don't solve the (IMHO, harder) problem of affecting change in the non-charter city areas, which will still face broader structural obstacles. The existence of a Hong Kong is not a sufficient condition for broad societal change, though it is certainly a helpful one, if not exactly necessary.

I'm happy to continue this discussion via email, no need to take up more of this thread.

New comment by shaddi in "The Politically Incorrect Guide to Ending Poverty"

shaddi — Thu, 03 Mar 2011 23:25:44 +0000

I never meant to say communism was responsible for the country's economic growth. Clearly, liberalisation caused that, as your graphs imply. However, the growth was concentrated on the coast, and the existence of a central command economy was the direct mechanism for infrastructure development in rural areas that were not directly benefiting from liberalisation. I don't claim communism is a good approach to economic growth, I meant it as a counterexample to the claim Hong Kong brought liberalism to the countryside and poverty went away. Hong Kong brought the wealth, Beijing redistributed it (violently).

I expect I was upvoted for commentary on the charter city idea, not because I proposed communism as an alternative. Thank you for bringing up an important point though.

Edit: please include the full sentence from my post, I think the part that you removed obscures my meaning.

New comment by shaddi in "The Politically Incorrect Guide to Ending Poverty"

shaddi — Thu, 03 Mar 2011 20:03:04 +0000

Of course, that is clear. However, declaring a Charter City won't magically erase corruption and other structural causes of poverty, and bringing in a foreign party to impose governance brings its own set of issues / has historically not worked out well.

Something closer to the lines of SEZs seems to capture the best of both worlds and makes more sense to me. It's a way to encourage liberalization (which we'll accept as a purely good thing for now, though obviously there is debate on that), bring in improved regulation, and provide some foreign expertise which could be helpful. It also aligns incentives a bit better, since it specifically focuses on business, rather than all aspects of governance (it's easier for us all to get along when we're in a mutually profitable relationship).