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Mesh Networks (motherjones.com)
312 points by dil8 on Aug 26, 2013 | hide | past | web | favorite | 99 comments

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.

And here is my response to Shaddi: http://thefnf.org/why-wireless-mesh-networks-will-save-from-...

imw Executive Director, The Free Network Foundation

Have you engaged with the FNF(http://thefnf.org) guys at all? They've got quite a thing going judging by their mailing list(s).

Also, what are your opinions on Guifi.net?

The article fails to make a good distinction for the different challenges of adhoc, infrastructure and privacy enhancing or censorship circumventing mesh networks.

Several others and I run a small (50 nodes) mesh network in my area, and it works fine for:

- enhancing WiFi access for all contributing nodes to an area which has limited or no coverage.

- providing fallback uplink connectivity for contributing nodes.

Infrastructure mesh networks are easy split into interconnected groups to avoid performance problems, and are still mesh networks, were a metropolitan area is covered by one ore more meshes to add redundancy and avoid scaling problems.

For enhanced privacy see http://www.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-12...

I'm wondering if software defined radio has anything to contribute here. Ultra wideband could help to mask the radio signals. Software defined antenna's could help with the directionality problem. This stuff is expensive today, but maybe not in a few years..

I'm really surprised that P2P doesn't scale on a mesh and would like to understand this better. I do research on message passing algorithms and obviously trees (hierarchies) are great, meshes are not... I can see that the overhead of routing messages is going to grow (like n^2?) with the mesh size, but i'm surprised there is no way around this.

In general, the market has overtaken hobbyist hacking by a wide margin. Any technique you are considering has already been considered and either adopted or abandoned by the Broadcoms of the world. Basically all radios are now SDR-ish but their firmware only contains a highly-optimized implementation of a single protocol (e.g. 802.11). Sure, a spinal code PHY with a mesh MAC will beat 802.11 by some percentage, but it costs 10x more because it's an FPGA instead of an ASIC so you end up switching back to Atheros/Broadcom radios.

I skimmed your paper, but I'm curious, based on your research into this area what an alternative would be to create private networks for citizens without laying out cable everywhere (which theoretically could also be tapped).

As opposed to wireless which doesn't have to be tapped (i.e. can just be listened in on with antennas)?

That's orthogonal. Private networks can be made up from any technology, privacy is another axis.

My point is that if you are opposed to cables because they can be tapped, wireless poses more problems....

Yes, but P2P mesh networks that are built for security have an advantage. They're encrypted end to end, for every node, and there's no one to implement a backdoor for the government, like in the case of ISP's. The ISP's right now are giving the government access all the data, unencrypted.

It's going to be a lot harder to "tap" a secure mesh network that's encrypted at every node. I would look more into this one:


I saw the 'also' in the ggp as referring to both wireless and cable networks. So he's aware of that.

This is true. And if the FCC were to give up spectrum for use in mesh networks, they could always require that no encryption be used. They mandate this with amateur radio. A HAM's license could be revoked if he was caught sending encrypted transmissions.

I've only skimmed your first link and parts of your paper, but in my opinion it misses the mark several places. For circumventing censorship, a pure wireless mesh is not in any way a requirement, for example.

The point for censorship circumventing meshes is to use whatever means possible to establish a routing fabric that gives anonymity and prevent authorities from tracking down or shutting of specific people.

It's perfectly fine in that case to route over mobile internet, over cable or ADSL connections, or over Wifi or any combination.

Your work seems to focus on a particular subset where someone for some reason have decided to go entirely wireless. But that makes little sense, not least because it means the network becomes entirely insular. Most network will want uplinks/downlinks to the internet, and the moment you spread such links through the mesh, most of your issues fall away, as it, for example, becomes ok or even advantageous to design the system to break wireless links and have the topology rearrange regularly and part of the routing could be to negotiate splitting and changing wireless links to break the wireless networks into smaller, but constantly changing chunks.

Your concern about omnidirectional networks swamping each other is similarly contingent on an all-wireless mesh, and a fairly dense one at that. I'm sure there are places where it is an issue, but I live in an substantially above averagely dense area, and I count about 10 wireless devices in my living room. I can detect about 5 other wireless networks around me, none on competing channels. If I bridged my network to two of those five, it would not substantially increase the amount of contention, especially as I know from measuring that several channels in normal wifi range are not used by any of my nearby neighbours, and given that I can compare to work, where we have 20+ computers with their own wifi networks on in the same room, paired with 20+ phones, and 10+ other large office networks visible.

Yes, the bandwidth to the internet would be low if we all were to try to piggyback off one uplink, but that would be silly. Instead, a proper privacy / censorship enhancing mesh would try to pass the traffic peer to peer where possible, and hand off parts of all the traffic to our upstream internet connections via encrypted connections to other parts of the mesh too.

When it comes to equipment, I have several wifi devices that fit inside a USB plug. Their antennas are not great, but easy to improve, so the idea that it'd be easy to prevent sales of suitable equipment is unlikely, I think - A USB hub plus a bunch of cheap USB wifi units + a $40 small computer, and you can bridge heaps of networks. In a situation with active censorship, there are enough consumer equipment that is trivial to create ad-hoc routers from, even if you worst case have to hook a bunch of bulky wifi access points together.

In fact, the possible units are cheap enough that I've been toying with the idea of bridging my own wifi along the 2 miles or so from my house to the train station I commute from by strategically hiding small android computers with an extra wifi interface, mostly for fun. The limiting factor now is no longer cost, but solving the power issue (finding a unit low enough power to be able to supply it via solar (I don't fancy the increased risk of trying to steak power anywhere along the route, though there's plenty of poorly protected tempting telco cabinets that'd be ideal) without making the units big enough that it'd be too hard to hide units along the road without having bomb squads called out...).

Routing protocols for large meshes certainly are still an issue, but that issue will only be solved if we actually try. And again it is worth keeping in mind goals. if your goal is to replace the public internet, then it's hard, as the bandwidth and latency requirements become a big challenge. If the goal is evading censorship, then you only need to pass certain traffic over the mesh fabric. In fact, the smaller percentage, the better, as much of the traffic will need to exit somewhere to bridge air gaps, and the smaller the traffic, the easier it will be to traffic mix and hide any encrypted exit traffic.

I hope this becomes a bigger trend, but if we're going to do this again, then I hope we do it right this time, and we make it as secure, as uncontrollable by governments, and as anonymous as possible (if you so make that decision on it).

The US government/NSA is ruining the old Internet, so I hope the new one will be very resistant to such attempts in the future. I would watch out especially for hardware-level backdoors for such an Internet.

If they can't spy on the network directly because it's P2P they will try to force either the OS vendors or the hardware vendors to implement backdoors and keyloggers for them. So at the very least the focus should be on open source operating systems with open source firmware (and possibly even open source hardware in the future). Such hardware should be given extreme preference for the mesh networks.

The TOR project has been doing some work on deterministic builds to deal with exactly that issue. https://blog.torproject.org/blog/deterministic-builds-part-o...

I never thought that the whole "trusting trust" essay would become a practical reality and an everyday danger that must be mitigated. But welcome to the 21st century. No flying cars, but lots of dystopian cyber punks eager to get in your business.

The problem is making it anonymous, uncontrollabe, P2P, flies in the face with other aspects like performance. Wireless links simply do not have the capacity to afford 10,000 people the speeds they are accustomed to today.

Excellent ...

I saw an article about this a little while ago. If anywhere in the world could support a wide scale mesh network, it would have to be the Bay Area. It would be a really cool experiment to blanket a part of the Valley in mesh wifi: I imagine it would be very doable to raise $100K and send 1,500 mesh routers to people in Palo Alto or SOMA. Open Mesh has some really cool low-cost ($50 - $75) hardware that seems to just work: http://www.open-mesh.com/. Some might be plugged into an upstream link, but if most were only powered on as relays it would still work.

A group of us are already well on the way in Oakland, stop by some time!


Are there any plans to connect up to an SF mesh? I could see setting up some backbones across the bay, but I'm not sure what the technicalities are around this.

WiFi reflection across the bay and the fog is murder. It basically makes all but high-power links useless...

rhodey - you have been hellbanned. It looks like your first comment ever was modded down, and that was that. Lame.

rhodey wrote:

A group of us are already well on the way in Oakland, stop by some time! https://sudoroom.org/wiki/Mesh

Hmm? I can see it, and I don't have "showdead" on.

I have showdead on and it was dead before, and now it's not. Maybe a mod saw it and fixed it or...?

I did give him an upvote, and maybe others did as well. Perhaps it was enough to raise rhodey from the dead? So perhaps my reports of rhodey's death were greatly exaggerated. Unfortunately I can no longer edit my original comment to reflect this.

There's a project started in the East Bay http://510pen.org/

I have a lot of experience with roofnet, Meraki and Open Mesh. They work to some extent, but not nearly with the degree of reliability that an ordinary customer would tolerate. You are not going to get a reliable network with single-radio devices in an urban setting with lots of interference and construction materials that are not friendly to wireless signals. You can do somewhat better if you plan out your backhaul links using traditional, non-mesh technologies and only use mesh for the very last few hundred feet, and stick to dual-radio N devices. There is a lot of hype about some of these networks in Europe (Athens, Austria, Berlin, etc.) but what people fail to realize is that these networks are used by geeks who are happy to build their own antennas, mess around with a linux shell, etc. If you just hand people devices you're not going to have a network that is tolerable for most consumers. It may work okay in a developing country in the middle of a revolution where people are willing to hack something together, but for ordinary consumers who want a reliable connection and don't care about the underlying technology it just doesn't work.

Before they radically changed direction and were acquired by Cisco, Meraki tried to target community meshes in SF and beforehand as Roofnet at MIT. They handed out/sold a lot of mesh APs. I wonder what happened to the boxes.

Several hundred roofnet devices were distributed to low-income housing in the South End and Roxbury neighborhoods of Boston. The networks are still limping along with some volunteer maintenance. There are some really dedicated people working to provide for some of the technology needs of the communities, such as free computer repair and training. Check out http://cstoboston.org/ http://www.tech-center-enlightentcity.tv/

Great to hear. Is someone making compatible hardware/software that interoperates?

And yet another mesh network, from HacDC hackerspace in Washington.


"The goal of Project Byzantium is to develop a communication system by which users can connect to each other and share information in the absence of convenient access to the Internet. This is done by setting up an ad-hoc wireless mesh network that offers services which replace popular websites often used for this purpose, such as Twitter and IRC." - from http://project-byzantium.org/about/

Small correction, Byzantium is a linux distro for several architectures with out-of-the-box mesh networking packages/drivers.

This was my first thought as well. I'm in the Bay. I'd do it.

While this is a great solution for places without easy last-mile connections, it seems to me this would still be vulnerable, as one compromised connection would essentially allow the same kind of snooping that we've got going on now.

Does anyone know whether this is so, or how to protect against snooping, as I would assume there is some implicit level of trust required for a network like this to stay secure.

A sort of invitation only controlled by social relations? not perfect but at least, misbehaving people can be trackable..

should be based in social connections and trust.. the old school policy

That creates an active incentive to physically lean on people to roll up networks.

cjdns works by requiring people to exchange keys with someone out of band to get access to their mesh, and to me that just seems as fundamentally defeating the purpose.

Yes, that means you need to build a system where bad guys are hard to impossible to track down and throw off the mesh. The problem is if you create a system where misbehaving people are trackable, then good guys can be tracked too.

I think you'd need to add the following constraints.

- Non-compromised endpoint hardware - In-person public key exchange - Onion routing

Creating non-compromised endpoint hardware is a bit of a problem. I'm actually not sure if it is possible, even in principle.

Maybe if there was an open source/open hardware router which contained a chip with secure boot, into which you yourself could burn the public key, and then it would only allow the code signed by that key... Sounds too complicated to be user friendly.

Besides, there is no way to verify that the hardware router that somebody considers to be secure was not replaced by an identically looking box that had been compromised :( .

Meshnets don't scale well anyway so perhaps strength in numbers applies here: if there are so many small meshnets that getting a mole in each one is totally impractical, spying on meshers en masse becomes totally impractical.

A couple comments mentioned wanting to build this in the Bay Area. I've been wondering for awhile why there's not an active group here.

Let's meet up to discuss more, how about a Google group to organize? https://groups.google.com/forum/#!forum/sf-meshnet

If you wanted to start a mesh network in your town, is there advice on how to protect yourself from legal liability in case someone does something clearly illegal with it?

Do mesh operators have the same "safe harbor" protections?

What if the FBI shows up on your doorstep and says "give us access or go to prison" ?

As of today I think not. Given the fact that MAN (metropolitan area networks - which is what these networks are) are way easier to monitor, because they are really small and into local police's reach (why call the feds anyway?).

The only decent point here, related to privacy is that it's way better for people to control the network instead of a police state, but you can't really be anonymous in such small MANs.

What do you do if your ISP says 'shut it down'?

The mesh itself should probably be an ISP. For whatever reason I get the impression that ISPs give downstream ISPs much more benefit of the doubt than they give end customers.

Similar thing exists in Melbourne, Australia: http://www.melbournewireless.org.au/

As well as Perth, Western Australia: http://www.wafreenet.org/

Thanks for posting this. I'm in Melbourne and I had no idea..

I'm in Melbourne too... started thinking about this while browsing reddit on the weekend, had no idea there was a group

There used to be one in Brisbane in the mid 2000s (BrisMesh), but it seems to be dead now.

Most capital cities in Australia had a wireless mesh project during that era. wireless.org[1] was (and still is?) the toplevel website.

Melbourne and Perth seem to be the only ones left with active nodes? Canberra (air.net) used to be strong. Sydney lives on in the form of a website[2] and nodedb[3], a world wide map of mesh network nodes, started by "evilbunny" (Duane Groth).

The servers are still live, but the content is well out of date. The projects are dead, but all the infrastructure seems to still be there, if interest ever revives.

[1] http://www.wireless.org.au/

[1] http://www.sydneywireless.com/

[2] http://www.nodedb.com/

"To repurpose the famous A.J. Liebling statement, internet freedom is guaranteed only to those who own a connection. "And right now, you and me don't own the internet—we just rent the capacity to access it from the companies that do own it," Wilder says."

I guess it makes sense that the future could be dominated by multiple, parallel internets of varying degrees of freedom. The corporate controlled internet we know today is just the mainstream realm of YouTube and email, while darker DIY internets pop up that are the realm of torrents, bitcoin and various hackery. Kind of seems obvious this would happen eventually

Im quite surprised that noone mentioned AirJaldi - which has to be some of the most pioneering work in this area, over some of the most inhospitable terrain.

It was built to connect the Tibetan community in Dharmsala, India using modified, off the shelf hardware and custom software at some of the hardest mountainous terrain where such equipment can be deployed.


Don't worry, if this idea gets adopted then they will quickly label it as a 'terrorist network' ; no problem.

Besides I think since it would be quite local networks, it could be easily jammed by few NSA stations in the area.

There is a huge community around wireless community networks in Germany. Checkout http://start.freifunk.net/

Don't miss the International Summit for Community Wireless Networks (http://2013.wirelesssummit.org/).


For best UX, set your "Referrer:" header to google.com

Also, I think Cisco paid over a billion for one mesh community network's project. I think a YC cofounder may have been involved in that project. Not sure. Its Cisco brand name is Meraki.

It appears portable autonomous networks (i.e. no telco needed) are useful and valuable for many, diverse reasons. I posit that if you can build your "no telco required" network from affordable parts and can get it to work consistently, then it has value, irrespective of whatever "intended uses" for it you might have in mind.

Of course, I could be wrong.

Also, I think Cisco paid over a billion for one mesh community network's project.

Meraki was worth $1B because they almost completely pivoted away from mesh towards more conventional networking.


If I build a better LAN, it might be used by companies with high maintenance corporate networks, or it might be used by high scoring gamers at LAN parties. The LAN technology does not fundamentally change, only the usage.

However, your point is well taken. As far as buzzwords go, "mesh network" is not in the same league as "cloud computing". You will not see "mesh network" in Cisco's marketing.

But was this really a "pivot"? Or is this a case of a use (corporate LAN) that differs from the original one (community LAN): what I would call an "unintended use".

My idea of a "pivot" is something like when some young developers want to start a company that takes orders for food delivery over the web but then, after consulting with the older folks who would provide funding, decide instead to build a news commentary blog that functions like a forum. That sounds like more than a change of usage. It sounds like an entirely different program. But maybe not. Maybe the system they create for taking orders is more or less the same one they use for taking comments on news items.

Anyway, it's an interesting story and regardless of how the stuff is being used now, it was originally used for creating "mesh networks", a type of portable network that could run with a telco. Now it is used, by Cisco customers, for creating "distributed networks".

My point is that newer Meraki products don't use mesh technology at all, so it's not just a different use case.

But, for example, Meraki products are used to create LAN's that have an OOB control plane. Correct? That sounds a lot like "supernodes", where Cisco runs the supernodes. Is that "traditional networking"?

I'm not clear on the exact definition of "mesh networking", but I think it implies forwarding data traffic. If so, that disqualifies Meraki. But I'm not sure of the purpose of your point (with which I agree) because I never used the terms "mesh networking" or "mesh technology".

For the record, I used the words "portable" and "no telco needed". In my mind, this encompasses more than just "mesh networks".

There's just a lot that has to be rethought for mesh networks to work as "show up with an antenna and you're on the internet/ are the internet". IP layer, I'm looking at you.

I remember being told about research being done on multi-core processing in the 70's, but no headway there could outpace the standard of shrinking the technology and increasing the clock rate. Now we may as well assume n-cores. It's my hope (because mesh networks sound way more democratized and just "seem" like the next logical way of scaling the internet) that antennas become cheaper at a faster rate than wired infrastructure (given the fairly inelastic cost of digging shit up) and mesh networks start to make sense.

This seems something like the Serval Project (http://www.servalproject.org/). Difference being that Serval is for mobile telecommunications meshes, rather than fixed(-ish) data connections.

Serval is referenced in the article, just not by name.

Could someone build this into DD-WRT or Tomato and then build this on top of WIFI / WLAN? In a built-up conurbation, you have a high concentration of WIFI routers that have a short range but with such a large concentration, maybe it doesn't matter?

We've also got the same thing going on in Montreal :) http://wiki.reseaulibre.ca (we're trying to figure out how to have a bilingual wiki...)

I live in the mountains (Central Arizona) and I have garnered some interest of other people in my community to set up a local mesh network. Really good in emergencies (e.g., east coast during Hurricane Sandy).

If you live in Seattle and you're curious about mesh networking, I highly recommend checking out http://seattlewireless.net/

They've been at it since 2000, have various nodes throughout the city and some impressive long distance directional links. (Seattle's topography provides some interesting challenges.) When I lived there in about 2005 there were regular wireless hack nights. Find Matt Westervelt or Rob Flickenger.

Submitted by me 2 days ago: https://news.ycombinator.com/item?id=6266765

What backbone protocol is largely used for these projects? I only ask because the range of even 802.11ac would be a limiting factor in these sorts of networks.

In densely populated areas, WiFi can suffice due to the mesh topology.

We should definitely do this in america, God we need this!

This is awesome, however, municipalities have put fear into people wishing to do this over legal issues arising from what someone might do on your connection. Who is to blame when something illegal (mp3 download, etc) happens? That whole issue needs to be put to rest so we as a society can create our own Internet without fear of suppression.

+1 great point. I sometimes leave my wifi open (I live in a small town, if that means anything) but then I consider the legal implications and lock it up for a while. ...then repeat...

The best solution would be allowing people to risk free run grid networks (which would be, I think, very low bandwidth) and have communities also supply separtae low bandwidth Internet connected wifi for free. We would then use a paid for service for anything for more than text or other low bandwidth uses. No one would download large mp3s, watch Netflix, etc. from the very low bandwidth community wifi, and the separate grid network would be local and likely not have anything to attract "Imperial interest" (sorry about the Star Wars metaphor :-)

Local grid networks could be part of support for local libraries, community centers, etc.

Having an open wifi should leave you free of any charges in the same way that an ISP is. Maybe it should be not culpable modulo keeping logs of everything for up to three months so that law enforcement can attempt to find anyone committing a crime once they have a warrant.

There probably is or was.

There was a surge in people doing wifi WAN style networks across whole cities, back when internet speeds were slow+expensive, and decent directional wifi antennas were available fairly inexpensively.

I think low-cost high-speed internet largely killed the need for it: perhaps Prism has given us a nudge to start again?

No doubt there are may others, but the one that comes immediately to mind is Personal Telco: https://personaltelco.net/wiki

Perth, Australia - WAFreeNet - http://www.wafreenet.org/

This is excellent! The Internet actually was supposed to be one InterNetwork of many. How is this different than a LAN though?

The Internet is an inter-network of many.

Also the "L" in LAN, stands for "Local".

I had been a member of the AWMN for some years. You can see a map of the nodes here: http://wind.awmn.net/?page=gmap

I remember AWMN had experienced a boost when the ADSL's were out but very expensive, so many people used to buy one and share it alltogether.

It has come a long way since.

Seems a stretch to say its untouchable. A policeman. An always show up and ask you to attach some hardware to the machine.

Or an antenna could just listen in on the signals.....

Reminds me of the packet networks that we hams used to build back in the BBS days. Most of the stations went off air with wide spread commercial internet service and operator turn over, but there's a renewed interest with newer, cheaper, radio gear come out.

Also there's many cities with a first responders mesh network.

There's been a renewed interest in this lately among hams, actually. http://www.hsmm-mesh.org/

I'm a little disappointed, though, that at least local to me most of the interest centers around hacking the old WRT-54G rather than more modern and powerful gear.

I'm surprised noone has linked to the FNF before. They seem to be one of the more organized mesh efforts in the US.


Anyone interested in getting a private mesh network set up in Silicon Valley? Seems like it would be a fun and educational project if nothing else.

What caught me was the localism - stunning

Am I crazy or did the URL of the submission change? I've never seen that done on HN before.

I've seen it happen on rare occasion when the original submission was content-free blogspam.

Again, the sudden title change of submissions suck.

Update: Thanks for changing it back.

Meshing has always been the end goal.

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