68 ms·

Why wireless mesh networks won’t save us from censorship

104 points by shaddi 15y ago

wglb 15y ago
This is a good article grounded in actual experience. As the former operator of the w8lvn packet radio bbs, i can heartily relate to you haven’t lived until you’ve hunted down transient connectivity problems resulting from RF weirdness in urban areas. And he details real-world experience like "omnidirectional antennas suck". Essentially, physics is not on your side here.
- wisty 15y ago
  A directional antenna or two with some kind of actuator might help. A couple of cantennas that could aim themselves could solve a lot of problems. But there's still a lot of problems left. Ultimately, you either get really poor bandwidth, or can only have static assets (like movie files, which don't need to change over time and can be cached by someone nearby with a few big hard drives).
  - ars 15y ago
    Sounds like a http://en.wikipedia.org/wiki/Software_defined_antenna http://en.wikipedia.org/wiki/Software_defined_antenna would be perfect here. Use omni to find nodes (low bandwidth, high noise), then make the antenna directional for the full communication (higher bandwidth, lower noise).
    - shaddi 15y ago
      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. :)
  - SomeCallMeTim 15y ago
    Directional antennas don't help create a "mesh", since they (by definition) only connect stations in a direct line with each other -- a mesh is supposed to connect to multiple other stations, so that if one goes offline, a route can be found through another. A directional antenna will only (typically) connect to one other node.
    - ticks 15y ago
      It sounds like a mesh network would require a couple of different routers: a low-cost model that lives in an already established area; and a more expensive model with antennas pointed at other established areas to act as a bridge.
    - wisty 15y ago
      If you had an antenna and an omni, though, you could connect a local subnet to the wider area. If you had a few directional antennas in each local subnet (say, an apartment complex connected by omnis), then the subnets would connect to the rest of the world. Wireless meshes don't work. They need to be fractal - local omnis, then cantennas, then backbones. If every geek had a cantenna (plus an omni to connect to the non-geeks, and another geek with a cantenna), you could light up most cities (OK, maybe not quite a city ... I don't really know). From there, you need some super-geeks finding ways to connect the city nets (private fiber?), but you don't need many super-geeks.
      - pyre 15y ago
        Isn't the problem with this, single points of failure? I guess it's still more of a mesh than the current infrastructure. But if you're trying to 'route around the government,' then having a defined structure seems counter to your goals.
        wisty 15y ago
        A full mesh is impossible. It just doesn't scale. You need a fractal system. You also need graceful degradation (or progressive enhancement). It would be great to push a tweat out, and have it visible on the local network until the local network can sync with the central server.
  - nate_meurer 15y ago
    802.11ac, the successor to 802.11n, specifies phased array antennas that are autonomously aimed by the device software. This doesn't solve all the problems of directional antennae, but it's a big step. 802.11ac devices are expected to be widely available at the consumer level within three years.
- xradionut 15y ago
  As a fellow ham and former military communications specialist, I concur. A lot of smart computer folks that don't have the theoretical or practical experience with RF to understand the issues at hand. But I'm nice enough to point them in the correct direction while resisting the tendency to sigh or giggle at some of the statements I hear.
marquis 15y ago
I'd like to note that every single item listed in this is a technical barrier. There are no political barriers, there are no wealth or resource barriers. RF is free to use on the spectrum we need it to work on (ok, until that's illegal). It's that it's a hard, hard problem to solve and it hasn't been solved yet. Do not let that stop anyone from continuing to do work on this: maybe it will get solved.
- shaddi 15y ago
  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.
  - sliverstorm 15y ago
    To me the damning evidence is that these problems still haven't been solved for decades even with a fair amount of work by professionals. Solutions probably exist, but will a decentralized group of redditors really be the ones who solve them? I personally figure if people just accept the low speeds of HF instead of expecting full Hulu streaming for everyone, a lot of the problems will be immediately mitigated, but that's unlikely- if only because HF gear is not nearly as cheap and ubiquitous as WiFI.
    - saulrh 15y ago
      There's precedent for well-communicating groups with a well-defined goal producing impressive results in the short term. Examples include the Manhattan project, the space race, and the more recent Polymath projects [1]. These redditors probably aren't the people to do it, but if the same attempt were made on comp.* or at google it might go somewhere. http://michaelnielsen.org/polymath1/index.php?title=Main_Page http://michaelnielsen.org/polymath1/index.php?title=Main_Pag...
- stfu 15y ago
deleted 15y ago
[deleted]
WiseWeasel 15y ago
OK, plan B. First, we quantum-entangle a few billion pairs of particles... Failing that, even without connecting the hundreds (or sometimes thousands) of square miles between cities, I think there is still great potential political, economic and recreational value in decentralized Metropolitan Area Networks, despite the fact that they won't supplant the Internet.
- wolfeater 15y ago
  As the project creator I agree. It will never supplant the Internet, but localized networks can play a huge role in how the web works however, and I see establishing these as the real goal of the project.
  - 110101001010100 15y ago
    It is crucial in my opinion how you define the goals of your project.
- ramidarigaz 15y ago
  Can't use quantum entanglement to transmit information unfortunately... It would be nice though.
  - WiseWeasel 15y ago
    Is there a reason to believe it would never be possible, or is it simply that we haven't found a way yet?
    - ramidarigaz 15y ago
      Here's one video. http://www.dailymotion.com/video/xkgklr_the-possibility-of-using-quantum-entanglement-to-transmit-information_tech http://www.dailymotion.com/video/xkgklr_the-possibility-of-u... It doesn't really explain things thoroughly, but it's the best I can find right now.
lucasjung 15y ago
One thing the article didn't mention, which I've been considering in regards to this problem: an RF-based internet alternative would be prone to all sorts of other forms of government interference/monitoring. The U.S. government already has serious resources at its disposal for the purpose of intercepting or jamming RF transmissions. For "intercepting," this includes high-power decryption capabilities, and for "jamming" this includes noise jamming but also spoofing and signal insertion. So even if an RF mesh-network of some sort were to be established, the government would be able to: 1: Know exactly where every transmitter is. This means they can find you in meatspace even more easily than they can on the hard-wired internet. 2: Listen in on your transmissions without all of the legal issues associated with wiretapping. To make sure they can do so, they would probably need to pass a law prohibiting the use of many types of cryptography on unlicensed RF transmissions. Such a law would be much easier to sell to the general public "because the terrorists could be using it to coordinate attacks." If you break this law, expect a knock on your door almost instantly because of #1, above. When you combine #1 and #2, busting "pirates" becomes trivially easy: somebody sees a "suspicious" file in your transmissions, localizes your transmitter, and a few minutes later you get a knock on your door. There's other stuff, like injecting false traffic, etc.
- IgorPartola 15y ago
  Just to clarify: are you saying with your point #2 that the government can break any encryption currently in wide use with 802.11 networks and all popular VPN solutions? Or are you just saying that they can physically listen to encrypted transmissions? I was under the impression that encryption scales in complexity pretty much infinitely, so long as you don't care about encryption/decryption speeds.
  - delinka 15y ago
    I had a relative that once worked in "government security" for the U.S. government. What that meant, we weren't permitted to know. Personally, I think he was full of crap and here's why: in his Professional Opinion, any encryption algorithm implemented in software was doomed to failure because "it could be hacked" - he was completely unaware that any hardware circuit can be emulated in software. Point: it tends to be these very gov't lackeys that think just because the signal is in the air that it can be intercepted, decoded, decrypted and its plaintext content recorded.
derekreed 15y ago
Yes, those are all problems, and they will require work to get around. Good point. "This will never work." << lol
sophacles 15y ago
This seems to assume that the only way to use a network is the current (near)instant req/resp style networking, which is core to a lot of current protocols. One of the things a darknet would enable is a slower eventual delivery model, like email used to be. This is not ideal, but opportunistic store and forward still can move information faster and easier than no network at all. Things like freenet and freedom boxes are attempts to look at this notion. In scenarios where the darknet is being actively attacked, people are likely going to be less concerned with instant services than any source of reliable, uncensored information. Perhaps we need to really look into ways to get information around following these methodologies and constraints as a supplement to building darknets.
- wmf 15y ago
  People are only going to buy the equipment in the first place if they can check their Facebook over it. A network that's designed only for freedom fighters ends up not getting enough nodes to reach critical mass (see Freenet). People might tolerate an Internet-incompatible network if it also came with lots of free warez, though.
  - v21 15y ago
    Piracy is definitely the draw for this. Enough to make it practical? Maybe - it depends on how many good alternatives to piracy exist.

104 points by shaddi 15y ago

wglb 15y ago

This is a good article grounded in actual experience. As the former operator of the w8lvn packet radio bbs, i can heartily relate to you haven’t lived until you’ve hunted down transient connectivity problems resulting from RF weirdness in urban areas. And he details real-world experience like "omnidirectional antennas suck". Essentially, physics is not on your side here.

wisty 15y ago
A directional antenna or two with some kind of actuator might help. A couple of cantennas that could aim themselves could solve a lot of problems. But there's still a lot of problems left. Ultimately, you either get really poor bandwidth, or can only have static assets (like movie files, which don't need to change over time and can be cached by someone nearby with a few big hard drives).
- ars 15y ago
  Sounds like a http://en.wikipedia.org/wiki/Software_defined_antenna http://en.wikipedia.org/wiki/Software_defined_antenna would be perfect here. Use omni to find nodes (low bandwidth, high noise), then make the antenna directional for the full communication (higher bandwidth, lower noise).
  - shaddi 15y ago
    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. :)
- SomeCallMeTim 15y ago
  Directional antennas don't help create a "mesh", since they (by definition) only connect stations in a direct line with each other -- a mesh is supposed to connect to multiple other stations, so that if one goes offline, a route can be found through another. A directional antenna will only (typically) connect to one other node.
  - ticks 15y ago
    It sounds like a mesh network would require a couple of different routers: a low-cost model that lives in an already established area; and a more expensive model with antennas pointed at other established areas to act as a bridge.
  - wisty 15y ago
    If you had an antenna and an omni, though, you could connect a local subnet to the wider area. If you had a few directional antennas in each local subnet (say, an apartment complex connected by omnis), then the subnets would connect to the rest of the world. Wireless meshes don't work. They need to be fractal - local omnis, then cantennas, then backbones. If every geek had a cantenna (plus an omni to connect to the non-geeks, and another geek with a cantenna), you could light up most cities (OK, maybe not quite a city ... I don't really know). From there, you need some super-geeks finding ways to connect the city nets (private fiber?), but you don't need many super-geeks.
    - pyre 15y ago
      Isn't the problem with this, single points of failure? I guess it's still more of a mesh than the current infrastructure. But if you're trying to 'route around the government,' then having a defined structure seems counter to your goals.
      - wisty 15y ago
        A full mesh is impossible. It just doesn't scale. You need a fractal system. You also need graceful degradation (or progressive enhancement). It would be great to push a tweat out, and have it visible on the local network until the local network can sync with the central server.
- nate_meurer 15y ago
  802.11ac, the successor to 802.11n, specifies phased array antennas that are autonomously aimed by the device software. This doesn't solve all the problems of directional antennae, but it's a big step. 802.11ac devices are expected to be widely available at the consumer level within three years.
xradionut 15y ago
As a fellow ham and former military communications specialist, I concur. A lot of smart computer folks that don't have the theoretical or practical experience with RF to understand the issues at hand. But I'm nice enough to point them in the correct direction while resisting the tendency to sigh or giggle at some of the statements I hear.

marquis 15y ago

I'd like to note that every single item listed in this is a technical barrier. There are no political barriers, there are no wealth or resource barriers. RF is free to use on the spectrum we need it to work on (ok, until that's illegal). It's that it's a hard, hard problem to solve and it hasn't been solved yet. Do not let that stop anyone from continuing to do work on this: maybe it will get solved.

shaddi 15y ago
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.
- sliverstorm 15y ago
  To me the damning evidence is that these problems still haven't been solved for decades even with a fair amount of work by professionals. Solutions probably exist, but will a decentralized group of redditors really be the ones who solve them? I personally figure if people just accept the low speeds of HF instead of expecting full Hulu streaming for everyone, a lot of the problems will be immediately mitigated, but that's unlikely- if only because HF gear is not nearly as cheap and ubiquitous as WiFI.
  - saulrh 15y ago
    There's precedent for well-communicating groups with a well-defined goal producing impressive results in the short term. Examples include the Manhattan project, the space race, and the more recent Polymath projects [1]. These redditors probably aren't the people to do it, but if the same attempt were made on comp.* or at google it might go somewhere. http://michaelnielsen.org/polymath1/index.php?title=Main_Page http://michaelnielsen.org/polymath1/index.php?title=Main_Pag...
stfu 15y ago

deleted 15y ago

[deleted]

WiseWeasel 15y ago

OK, plan B. First, we quantum-entangle a few billion pairs of particles... Failing that, even without connecting the hundreds (or sometimes thousands) of square miles between cities, I think there is still great potential political, economic and recreational value in decentralized Metropolitan Area Networks, despite the fact that they won't supplant the Internet.

wolfeater 15y ago
As the project creator I agree. It will never supplant the Internet, but localized networks can play a huge role in how the web works however, and I see establishing these as the real goal of the project.
- 110101001010100 15y ago
  It is crucial in my opinion how you define the goals of your project.
ramidarigaz 15y ago
Can't use quantum entanglement to transmit information unfortunately... It would be nice though.
- WiseWeasel 15y ago
  Is there a reason to believe it would never be possible, or is it simply that we haven't found a way yet?
  - ramidarigaz 15y ago
    Here's one video. http://www.dailymotion.com/video/xkgklr_the-possibility-of-using-quantum-entanglement-to-transmit-information_tech http://www.dailymotion.com/video/xkgklr_the-possibility-of-u... It doesn't really explain things thoroughly, but it's the best I can find right now.

lucasjung 15y ago

One thing the article didn't mention, which I've been considering in regards to this problem: an RF-based internet alternative would be prone to all sorts of other forms of government interference/monitoring. The U.S. government already has serious resources at its disposal for the purpose of intercepting or jamming RF transmissions. For "intercepting," this includes high-power decryption capabilities, and for "jamming" this includes noise jamming but also spoofing and signal insertion. So even if an RF mesh-network of some sort were to be established, the government would be able to: 1: Know exactly where every transmitter is. This means they can find you in meatspace even more easily than they can on the hard-wired internet. 2: Listen in on your transmissions without all of the legal issues associated with wiretapping. To make sure they can do so, they would probably need to pass a law prohibiting the use of many types of cryptography on unlicensed RF transmissions. Such a law would be much easier to sell to the general public "because the terrorists could be using it to coordinate attacks." If you break this law, expect a knock on your door almost instantly because of #1, above. When you combine #1 and #2, busting "pirates" becomes trivially easy: somebody sees a "suspicious" file in your transmissions, localizes your transmitter, and a few minutes later you get a knock on your door. There's other stuff, like injecting false traffic, etc.

IgorPartola 15y ago
Just to clarify: are you saying with your point #2 that the government can break any encryption currently in wide use with 802.11 networks and all popular VPN solutions? Or are you just saying that they can physically listen to encrypted transmissions? I was under the impression that encryption scales in complexity pretty much infinitely, so long as you don't care about encryption/decryption speeds.
- delinka 15y ago
  I had a relative that once worked in "government security" for the U.S. government. What that meant, we weren't permitted to know. Personally, I think he was full of crap and here's why: in his Professional Opinion, any encryption algorithm implemented in software was doomed to failure because "it could be hacked" - he was completely unaware that any hardware circuit can be emulated in software. Point: it tends to be these very gov't lackeys that think just because the signal is in the air that it can be intercepted, decoded, decrypted and its plaintext content recorded.

derekreed 15y ago

Yes, those are all problems, and they will require work to get around. Good point. "This will never work." << lol

sophacles 15y ago

This seems to assume that the only way to use a network is the current (near)instant req/resp style networking, which is core to a lot of current protocols. One of the things a darknet would enable is a slower eventual delivery model, like email used to be. This is not ideal, but opportunistic store and forward still can move information faster and easier than no network at all. Things like freenet and freedom boxes are attempts to look at this notion. In scenarios where the darknet is being actively attacked, people are likely going to be less concerned with instant services than any source of reliable, uncensored information. Perhaps we need to really look into ways to get information around following these methodologies and constraints as a supplement to building darknets.

wmf 15y ago
People are only going to buy the equipment in the first place if they can check their Facebook over it. A network that's designed only for freedom fighters ends up not getting enough nodes to reach critical mass (see Freenet). People might tolerate an Internet-incompatible network if it also came with lots of free warez, though.
- v21 15y ago
  Piracy is definitely the draw for this. Enough to make it practical? Maybe - it depends on how many good alternatives to piracy exist.