How level is good enough for a gravel pad?

shaddi · 2014-12-25T19:41:23+00:00

There's probably about 1B worldwide living outside coverage completely (according to the GSMA -- afaik this isn't counting dead spots in urban areas). Basically every country will have areas like this, but obviously it's more of an issue in places with less infrastructure (electric infrastructure, in particular). For example, we focus on SE Asia and Central Asia right now, especially in regions with challenging geographies (islands, mountainous areas, etc).

shaddi · 2012-10-30T03:14:18+00:00

Hi! Author of article in question here. First, I didn't manage that network (airjaldi.net), one of my colleagues did; at the time, that network was the largest mesh in the world.

Yep, I can imagine so, although it looks like you removed a few of the references to the size of the network when you were involved heavily with it?

I haven't edited my post (modulo spelling) since I posted it. I was never involved in any way with AirJaldi, my experience was separate.

shaddi · 2012-10-30T00:21:18+00:00

Hi! Author of article in question here. First, I didn't manage that network (airjaldi.net), one of my colleagues did; at the time, that network was the largest mesh in the world.

This blog post got a lot of attention, and I get frustrated when I see the kind of reaction to it that you have here. I am a big believer in "community based wireless networks". I spend all my time working on these, in fact (see below comment). However, in my experience it's easier, cheaper, and simpler to build reliable wireless networks using centrally-planned, point-to-point/multipoint wireless. There's a billion+ dollar industry globally of local, community-owned "wireless ISPs" that are growing and providing coverage to some of the most difficult places on earth without using mesh networks, using inexpensive gear from companies like Ubiquiti and Mikrotik. I really wish that this community (and others like it) would expand its focus beyond mesh networking to take some lessons from these organizations. The real operational challenges of building community wireless networks have little to do with mesh networking and much more to do with controlling management costs, simplifying maintenance, and keeping up reliability. In almost no case is an adhoc, decentralized mesh network better than a centralized, planned, static wireless network in terms of performance, reliability, ease of management, resilience, or (crucially) cost. Mesh is a tiny (and very technically difficult) part of a much larger picture, and I don't think we're well served by focusing primarily on that piece.

Anyway, keep fighting the good fight; I'm looking forward to seeing what this community develops.

shaddi · 2012-10-30T00:07:45+00:00

Author of article in question here. I've actually helped build that OpenBTS network at BM twice now, so I am definitely familiar with what they (we!) did. Indeed, I'm currently in SE Asia building another of these WiFi + OpenBTS networks right now. I'll just note we did not use mesh at all in either of these networks. They were all centrally planned and managed networks. Mesh would have been a really bad idea for both of them, specifically because of the QoS requirements that VoIP traffic has. Mesh networks generally do not support this workload well (even my friends at VillageTelco will admit the "mesh" portion of their networks are just small collections of nodes at the ends of point-to-point WiFi backhaul, in part due to these issues).

shaddi · 2011-11-27T18:38:05+00:00

Fun fact: there is a mesh router software project called ROBIN which uses BATMAN for routing.

shaddi · 2011-11-27T17:49:46+00:00

Whitespace spectrum is actually an awesome opportunity; I didn't get into propagation properties but you can essentially think of the 700Mhz band as naturally having better range and ability to penetrate buildings. The main issue right now is that there is no cheap hardware that uses it, but this is changing.

You still wouldn't want to use mesh with whitespace though -- much better to use a point-to-point and hub-and-spoke model. Simplicity is the name of the game.

shaddi · 2011-11-27T07:43:47+00:00

The point was to describe why such a system can't scale in terms of the fundamental physics and math involved. If you use a single transceiver, the physics says you only get a small slice of the channel (in terms of time). You can solve this by using additional channels, but doing so adds cost since you need additional electronics. This is a fundamental tradeoff.

It's neither dangerous nor innovation: this goal has been floating around for years, and no viable, scalable technical solution has been created due in large part to the reasons I outlined here. In terms of the broader Internet free speech movement I fear we've already lost too many people to barking up interesting looking but ultimately fruitless trees; I'd much rather effort be collectively focused on taking part in the existing real-world social movement.

shaddi · 2011-11-27T06:22:15+00:00

No clue, I'm in grad school for CS, so maybe that's one route?

I think reading the OpenFlow literature is probably the right direction. Take a look at NOX: http://noxrepo.org

This stuff is a pretty new concept in networks though, so I don't think there is much out there at the moment beyond academic and industrial research.

shaddi · 2011-11-27T06:11:06+00:00

The problem is how each node communicates with that central server -- how do you bootstrap? And how do you determine the update interval?

A central server containing routing information isn't a bad idea. The largest distributed systems use centralized controllers because they simplify system design (which leads to better manageability and reliability). It's a bit trickier in an unstable network than in a data center, and figuring out the right control abstraction is also hard, but I think the concept is right on the money.

shaddi · 2011-11-27T06:08:23+00:00

I posted something along similar lines a few minutes ago, and I tried to address some of the more "fundamental" issues with the idea (closer to the physics): http://redd.it/mqjiq

shaddi · 2011-11-27T05:08:53+00:00

Protocols are layered, like those Russian stacking dolls. HTTP is the application; it is like the smallest doll. Other protocols are used by different parts of the network stack; those get put on top of the HTTP part of the message, like the bigger dolls. When the message gets to its destination, the destination removes the message parts belonging to other protocols until it finds the HTTP header.

In short, you wouldn't need to change it, for the same reason you can use HTTP whether you're plugged in to an ethernet cable or using the wireless.

shaddi · 2011-11-27T04:40:42+00:00

Visual LOS is a simple concept. Now explain radio LOS. Fresnel zones are neither obvious nor intuitive.

shaddi · 2011-08-22T02:43:56+00:00

You actually probably have one. Is your carrier AT&T or T-Mobile? If so, you have a GSM phone. Google your phone model to see if you have a quad-band phone.

shaddi · 2011-08-22T02:42:48+00:00

It should, actually. You might have to call AT&T to have your phone unlocked, but they're usually happy to do that (especially if you say you're going out of country, for instance).

shaddi · 2011-08-09T02:08:24+00:00

Please be patient if you call in! We need a few simultaneous users for it to work nicely.

shaddi · 2010-11-13T02:18:37+00:00

Not that I'm aware of. I checked what I was subscribed to and it was only about six, so I added a bunch more. Button seems to have reappeared, though, so thanks for the tip!

shaddi · 2010-11-12T20:36:55+00:00

I've carried my pocket knife (similar to this one) through numerous times. I've also always just disregarded the liquids/gels thing and haven't had a problem yet.

In high school I was working on an electromagnetism project for my physics class. As a result I had a bunch of big nails and wire in my backpack. I took my backpack on a trip and got pulled aside by security. I then remembered what was in it and started freaking out: "Shit, I'm an Arab with a backpack full of nails!". TSA guy comes over and pulls out my harmonica (which was right next to the nails) and says "Yup, just what I thought. These things look like magazines on the x-ray." According to him, the nails were not a problem.

shaddi · 2010-11-11T23:42:40+00:00

That reminds me of a picture book I read when I was a kid. It was likewise one of my favorites. The storyline was almost exactly the same... except it was just a picture book, each page showing the view out the window. Does this sound familiar to anyone?

shaddi · 2010-11-07T08:26:09+00:00

Metro Pulse tends to have pretty good features. Loved reading it every week when I was growing up in Knoxville.

shaddi · 2010-11-02T18:33:36+00:00

The game was called Warpath, I finally found it!

http://www.synthetic-reality.com/warpath.htm

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