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Communications Networking

Ask Slashdot: Could We Build A Global Wireless Mesh Network? 168

An anonymous reader wants to start a grassroots effort to build a self-organizing global radio mesh network where every device can communicate with every other device -- and without any central authority. There is nothing in the rules of mathematics or laws of physics that prevents such a system. But how would you break the problem up so it could be crowdfunded and sourced? How would you build the radios? And what about government spectrum rules... How would you persuade governments to allow for the use of say, 1%, of the spectrum for an unlicensed mesh experiment? In the U.S. it would probably take an Act of Congress to overrule the FCC but a grassroots effort with potential for major technology advances backed by celebrity scientists might be enough to tilt the issue but would there be enough motivation?
Is this feasible? Would it amass enough volunteers, advocates, and enthusiastic users? Would it become a glorious example of geeks uniting the world -- or a doomed fantasy with no practical applications. Leave your best thoughts in the comments. Could we build a global wireless mesh network?
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Ask Slashdot: Could We Build A Global Wireless Mesh Network?

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  • by mellon ( 7048 ) on Saturday April 29, 2017 @07:23PM (#54326607) Homepage

    https://freifunk.net/en/what-i... [freifunk.net]

    The problem would be establishing trunks to carry enough traffic to make it worthwhile, or figuring out a way to distribute the traffic over many links so as to (again) make it worthwhile. I think streaming would be hard. And of course it would be an ecosystem, in which bad things could grow, just like the net is now. You have to solve the problem of DDoS to make this work, I think, and I don't know of anybody who has any idea how to solve that problem.

    • gives a true meaning to a wireless laptop not to mention all other electrical devices that need to be plugged unto a wall outlet so you can trip over the cords.
    • To say it differently: the people who live next to Google better have a lot of bandwidth.
    • The problem would be establishing trunks to carry enough traffic to make it worthwhile...

      That's only one problem, and that's just within a single neighborhood. The much bigger problem is how a mesh network would traverse countries and continents (even the friendly ones) without massive funds from the very people and companies who would be actively fighting against such a network.

      • by mikael ( 484 )

        Giant pringle cans. A basic pringle can can be used to amplify a wifi signal over 3 km. Therefore, to get a signal to cross the Atlantic, we would need pringle cans 300x times the size. Maybe we could stack them vertically.

        • by Ozoner ( 1406169 )

          You can stack antennas to get more gain, it's called a Co-Linear or Phased-Array.

          But trying to get over the horizon does not scale linearily, Once you lose Line-of-Site, more gain doesn't much help.

        • by mellon ( 7048 )

          ...now, imagine a twinkie 35 feet long weighing 600 pounds...

  • by Hognoxious ( 631665 ) on Saturday April 29, 2017 @07:25PM (#54326613) Homepage Journal

    I live in Australia, you insensitive drongo!

    • by Anonymous Coward

      Indeed, all these mesh network fanatic seem to forget that outside the densely populated cities where they live there are vast sparsely populated areas. How does your mesh network reach those areas without being prohibitively expensive?

      Also, no government is going to allow a mass communication network that they cannot control, especially not with the current political climate. They all want to clamp down harder on global network we have now.

      captcha: economy

      • Re:Betteridge (Score:5, Interesting)

        by geoskd ( 321194 ) on Saturday April 29, 2017 @08:09PM (#54326769)

        Indeed, all these mesh network fanatic seem to forget that outside the densely populated cities where they live there are vast sparsely populated areas. How does your mesh network reach those areas without being prohibitively expensive?

        Even within densely populated areas, the technology doesn't scale well. This only works well at a very specific device density. Field testing has shown that much above or below this density, the performance of the system becomes badly sub-optimal.

        It should also be noted that at no density is the technology performance competitive with hardwired providers. This is because as the density goes up, you need more and more primary gateway routers to keep the link latency and link saturation down. This turns out to be right around 2.2 hops per primary access (hard-wired) nodes. In practice, this requires so many hard links that you don't save much compared to just providing hard links to every home, and everywhere that mesh technology is economically viable, hard wired access is also economically viable and vastly superior in performance.

        Lastly, the technology is highly susceptible to spectrum poisoning. The only good solution to that is to have a dedicated piece of spectrum for just mesh technology, but that spectrum would be worth close to $100B, and that alone renders the technology completely uneconomical. Current mesh solutions use the 2.4GHz and 5GHz bands, but both of those are also used by just about every home wifi that is included with any type of Internet access. This punches holes in the mesh that cannot be effectively compensated for. This is only going to get worse as the IOT becomes more and more prevalent.

        There are a few mesh networking startup providers that I am aware of, and all of them are plagued by poor performance, poor profitability and poor service reliability. I fully expect the introduction of 5G wireless spectrum from the established cellular carriers to put the final nail in the mesh coffin.

        • by Anonymous Coward

          We could totally do a 'mesh network', however it would not be a mesh network containing all multi-directional antennas. It would require layering point to point nodes for long distance travel with localize links using either multi-directional antennas, or an array of narrow antennas (say 4x90 degrees, each driven by a separate wifi router.) There would be dead spots, and it would not be the mostly seamless experience of cell phone access. However it is certainly possible, especially with IPv6 module address

        • The result I have is that in a mesh a random routing algorithm takes on the order of 55n to the number n of nodes to reach from one to another specific node, not sure if absolutely or on average. I stick to it, but could not find the paper again to review it. So if you take a billion nodes, it takes on the order of 55 billion steps to reach the other guy... not sure we have processors or the frequencies for that to be useful, the switching, etc. Go figure.
    • Re:Betteridge (Score:4, Interesting)

      by Nutria ( 679911 ) on Saturday April 29, 2017 @07:47PM (#54326679)

      Spanning oceans was the first thing I thought of.

    • I live in America and only say "drongo" in the arvo.

      I lie.

      I must Google, "drongo [wikipedia.org]."

  • APRS (Score:2, Interesting)

    by Anonymous Coward

    Or APRS? https://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System

    • by Anonymous Coward

      My first thought as well, it's down fall has always been bandwidth.

      • Precisely, us ham types have had this virtually forever. Agreed as well, bandwidth is the limiting factor. Really even SSTV or traffic nets could be seen as a simple global network example from which to build upon. Relying on RF over infrastructure has its benefits, and even in a wireless mesh network there is still much heavier reliance on infrastructure than traditional amateur or military radio networks.

        -- kc2kth

  • There is no business (ie. government) that would allow this to happen. Period...

    Even if you somehow managed to get it started, it will be regulated away. I mean you can't have people doing their own thing, doing it cheaply, and helping others. That's the devil's work!

  • by Anonymous Coward

    It is way too easy to just pay some cable company and not think for oneself.

  • by Anonymous Coward

    You need to convince or persuade a lot of people. That is what makes this a hard problem. Geeks and nerds aren't particularly great at convincing or persuading people, but they're the people who would have to do it, because they're the kind of people who would want a global wireless mesh network. I know I've thought about it. Who hasn't?

    • I think it is a problem of persuasion, as you state, but _also_ a technical problem, which makes it something that is doubly hard to achieve. Make one or the other easier / manageable and you have a fighting chance.
  • Routing (Score:5, Interesting)

    by Orgasmatron ( 8103 ) on Saturday April 29, 2017 @07:54PM (#54326703)

    IPv6 addresses are allegedly distributed in a way that reduces the routing table bloat seen in IPv4. With no central authority, how do you manage that?

    Storage and processing are both getting cheaper sorta fast-ish, so it may be practical now or in the near future to have a routing table with 2^36 entities (or whatever) and 3 or 4 entries per entity. But how do you pass it around? If my westbound link goes down, I'm no longer the fastest relay to half of the world from a not-trivial portion of my region. How many megabytes is that update?

    I'm not sure that the problem is unsolvable, but I don't have any reason to believe that someone out there is sitting on a revolutionary global mesh routing algorithm, waiting for the right time to publish.

    • Re: Routing (Score:5, Insightful)

      by TWX ( 665546 ) on Saturday April 29, 2017 @08:15PM (#54326783)

      Routing was the first problem that came to my mind too. An unreliable network requires a fast routing protocol, but fast routing protocols are very traffic-intensive for large networks. A large wireless mesh network would spend an inordinate amount of it's bandwidth just keeping converged.

      That's before dealing with security/trust issues. It's already proving a problem on slow routing protocols as the recent Russian incident shows where relatively few people have to be trusted, it would be much worse with every small player possibly being able to make adverse changes.

      • by dbIII ( 701233 )
        I wrote it elsewhere, but back when this site was still very new there were mesh projects with "backbones" of a sort where the owners would always keep their nodes on. Routing doesn't have to be much more insane than it already is.
        There's also been a few more recent papers about large IoT mesh networks and how to handle getting signals around without everything just blasting a central node with raw power to get heard. It's a pity the IoT people don't read such things before building their stuff.
        • by TWX ( 665546 )

          If I surmise those projects correctly, there was a fairly important degree of central control and some kind of authority to make decisions, and the mesh networks were of limited scope. A mesh network of the size that the article presumes would be massively more complicated and would have to be able to react dynamically to outages.

          The current Internet has a combination of a limited number of players for backbone and a fairly slow routing protocol that is fairly limited who gets to participate. A routing pr

      • by Anonymous Coward

        Super-peers and DHT solved this.

        Essentially super-peers are high-bandwidth trusted nodes that can pass you routing information.
        Of course, given we are speaking a system with a likely semi-fixed top bandwidth, we need a new system.
        We could randomly allocate super-peers in the network.
        A simple comparison between multiple super-peers will prevent people fucking with the records for abuse.
        The larger the network, the harder it'd be to abuse. Even with everyone being intelligent. Even if everyone felt like the

      • by MartinG ( 52587 )

        VIrtual ring routing appears to solve some of these problems.

        http://www.microsoft.com/en-us... [microsoft.com]

        I've been reading about this kind of stuff recently, and I'm considering attempting to implement it.

        Right now though, I'm writing a test harness to compare various routing algorithms and see how many nodes they can scale to before they fail (also, how much churn they can support, how they handle partitions, etc)

    • IPv6 addresses are allegedly distributed in a way that reduces the routing table bloat seen in IPv4. With no central authority, how do you manage that?

      I'm not sure that the problem is unsolvable, but I don't have any reason to believe that someone out there is sitting on a revolutionary global mesh routing algorithm, waiting for the right time to publish.

      I have a project in the works where a future piece of it is intended to address this issue. I'm essentially waiting for the right time to publish. Since it's the current discussion here, here's the relevant part...

      My intention is to use a piece of IPv6 space and encode a lat/long into it in a way that: A) you only have to make sure that no one near you is using the same lat/long, and B) for networks far away from you, you can represent many of them in a single entry line in your routing table. A network

  • The Governments would demand no "internet", all kinds of limits on what could be said, what kind of data could be networked and who would have to fill in official paperwork for the network.
    Once all that is done its POE to the roof and getting a dish network ready.
  • by raymorris ( 2726007 ) on Saturday April 29, 2017 @08:06PM (#54326755) Journal

    A very large mesh network *used* to be possible. Not so much anymore.

    > There is nothing in the rules of mathematics or laws of physics that prevents such a system.

    In fact there the laws of physics DO put some serious limitations on it, especially a true mesh network. In a nutshell, the frequencies that carry over distance and through walls have limited bandwidth, which must be shared by *everyone* who wants to use any kind of wireless communication. Frequencies above 10 Ghz have a lot of bandwidth, but don't go through drywall. Also of course high frequency waves have high energy - think microwave oven.

    Mesh networks are horribly inefficient in how they use the limited bandwidth available in desirable frequency bands. You can do much, much better if you have local transmitters around 1 Ghz communicating with local towers which form a backbone connected via high power dishes, or better yet fiber optics. There is a lot more usable bandwidth to go around using the backbone topology rather than wasting most of the bandwidth by using a mesh. That brings up the issue of who owns and controls the backbones.

    Given the physics of it all, back in 1990 you could have built a mesh network to replace the wired connections of the day - 48Kbps max bandwidth, with each person using it an hour or two per day, on average. On a new network built today, you'd want 100,000 to 10,000,000 Kbps, with each person using it ten hours per day. So roughly 40,000 times as much total bandwidth. Not going to happen. Not with the physics we know in this century.

    There *is* a way we can 40,000 times as much bandwidth as we had in the the 1990s, though. We actually have such a system working in much of Texas. It involves setting the greedy corporate ISPs up in a situation where to make money, they have to compete with other greedy corporate ISPs. Customers choose the best one, so an ISP can't make money if they suck. It's not a perfect system, but it beats the hell out of what I hear people on the coasts complaining about - a single monopoly ISP protected by a government franchise, an ISP that sucks but they don't care because nobody is allowed to offer competing service.

    • by dbIII ( 701233 )

      especially a true mesh network

      When this site was still shiny and new there were mesh projects that had paths of designated nodes to make backbones of a kind that get around that problem of getting stuff from one end to the other of a mesh 100km wide or so.
      You don't need a "true mesh" to get a mesh. A bit of redundancy is good but having thousands of possible paths over a relatively short range is overkill IMHO.

  • No. (Score:2, Insightful)

    by Anonymous Coward

    Next question.

  • by brian.stinar ( 1104135 ) on Saturday April 29, 2017 @08:22PM (#54326803) Homepage

    There are no laws of physics in the way.

    We cannot agree on global declarations of human rights, property rights, units of measurement, or basically anything else.

    So, no. We could not build a global mesh network. It's physically possible with technology from 10-15 years ago, but it is clearly impossible with the current political concept of "global."

  • There is probably the possibility of it happening in the reasonably far future in decently large cities. There are a couple problems with making a giant mesh network. A couple have been mentioned above.

    Routing tables would be fairly hard to figure out how to handle effectively, especially if each device in the mesh network could move around ( like if we were using a cell phone as a node in the network ). The routes would have to update extremely fast with extreme variability in each nodes transfer speeds,

  • by TheOuterLinux ( 4778741 ) on Saturday April 29, 2017 @08:40PM (#54326881)
    Would you be comfortable connecting your IoT devices with strangers? Probably not.
  • You mean like packet radio [tapr.org]?

  • by Gravis Zero ( 934156 ) on Saturday April 29, 2017 @08:48PM (#54326923)

    How would you persuade governments to allow for the use of say, 1%, of the spectrum for an unlicensed mesh experiment?

    1% of the spectrum is HUGE. You don't need 1%. However, you don't have to convince anyone because you can just use one of the ISM bands because they are free to use for whatever.

    However...

    The problem with a large-scale mesh network is that you are going to end up needs to make a LOT of hops just to reach your destination. With every hop, you get a little bit of latency and that number adds up quickly. I think to do this on a global scale in a way comparable to our current system that you would need a ASIC to do all the routing quickly. If you are serious about this, you can start off by using an FPGA to manage the radio and routing. You need to design the routing so that it can restructure routes quickly based on throughput, including zero throughput.

    If you build it, democratic governments would be hardpressed to try and stop the general public from using it, so they would approve it's use even if previously denied because they could easily be replaced by someone who will approve it.

    • by AmiMoJo ( 196126 )

      ISM band has limits. In most of the world the bands available for data have duty cycle limits, usually 1%.

  • So you saw the new episode of Silicon Valley too, eh?

  • Before you even consider this, get the FCC on your side. Get a group of savage lawyers who know how to fight. It's got to be air tight legal permission. If you think that they are not going to be out to squash your competition like a bug, 'you got another thing comin'. https://www.youtube.com/watch?... [youtube.com]
  • sure, but you'd need nodes and supernodes and ultimately ultranodes to handle traffic distribution (probably one supernode per 350 users handling id handshakes and content cross filing) and although the each node would be network-selected on a adhoc basis they would generally be sticky (central server-like) and would be voluntary, in as much your personal node, if you were running one, would be saturated, swamped as it were with boring traffic and housekeeping duties as opposed to the fun stuff of p2p chit

    • To make it useful, you would need data caching at each node so the system is tolerant of poor reliability and low bandwidth.

      This ultimately limits its value as a de-centralized system.
  • by dbIII ( 701233 ) on Saturday April 29, 2017 @09:57PM (#54327109)
    There was a mesh project in my area that was getting up to quite a few nodes but no internet service providers would allow any gateways from the mesh to the internet to exist. Multiple attempts to make a deal with several ISPs were met with demands to pay full residential account fees for every single node in the mesh before any connection would be allowed.
    It was seen as competition to be stamped out.

    So to do it you need some sort of bargaining power, such as a government telling the ISPs to give you a chance, or some way to get around the ISPs completely. If there is a long way to the next major city it's a bit tricky to get there without an ISP providing the link.
  • The first thing is getting the F.C.C. to add a new licensing test and small frequency range for extreme novice operators. The test needs to be online, since in many areas it is hard to find 2 seasoned H.A.M. operators to test you at the current novice level. But with this new restricted operators level, you would still get an operators call sign. Then the hardware needs to be inexpensively packaged, but powerful enough to traverse in hilly or tree infested areas; to reach other persons locally. But reachin
  • by Rick Schumann ( 4662797 ) on Saturday April 29, 2017 @10:12PM (#54327161) Journal
    Yes, you might well talk people into investing a little for a node on your mesh network. But just like Bitcoin, it would almost immediately be corrupted into something used to commit crimes. First and foremost it would end up being like another Darknet for pedophiles to traffick in child porn. Right on the heels of that would be filesharing of all kinds, heavily in movies and TV shows. Before too long someone would start setting up servers and it's subversion into a full-on Darknet would be complete; you'd have illegal drugs and other contraband, and crime-for-hire freely available. This would exist for a while before law enforcement got wind of it, and people would start being rounded up and their nodes confiscated, starting with the pedophiles and drug dealers; some outraged politicians would pass legislation making it illegal, or there would be application of existing laws to shut the whole thing down as illegal, and it would all fall apart. Corporations would back all this police action because a free mesh network would cut into their profits anyway.
    • Or, in other words, the society you know needs the law enforcement because without law enforcement it could not self-organize and inevitably falls into chaos. Next question is where you should find the law enforcement personnel that is NOT the part of your society.

  • Don't need to say any more really.

  • by SuricouRaven ( 1897204 ) on Sunday April 30, 2017 @02:53AM (#54327689)

    The above critics are right - while such a construct might be possible in theory, the practical difficulties may be insurmountable.

    But there is one technology that could make it, if not feasible, at least a bit closer to that goal: Content-addressed networking. Build a decentralised store for static content into the network from the beginning. That way you don't need to get people from all over the world all trying to access one server to download a popular file - if the person next door already has it, they can take the file from that much-closer source automatically. I suggest using IPFS as the base for that functionality, as it's already decently mature, reliable, and has a very elegant data structure that can scale endlessly.

    Now you still need your mesh to enable real-time communication, but you've taken almost all the load relating to static content distribution off if it. The capacity requirements are slashed.

  • by Rufty ( 37223 ) on Sunday April 30, 2017 @06:21AM (#54328037) Homepage

    AREDN [aredn.org] The Amateur Radio Emergency Data Network, and a node map [aredn.org]
    The still-widely-deployed predecessor, BroadBand Hamnet [broadband-hamnet.org]
    A port of this mesh to the RaspberryPi, HSMMPI [wordpress.com]
    Previous versions were called ARESNET and HSMMNET.
    And there's also the European ham network, here [hamnetdb.net] and a map [hamnetdb.net].

    • Amateur Radio has the severe legal usage limitation. It could be used for exchange of amateur radio and emergency related information ONLY. So it could be used as an experimental base ONLY and then the technology should be transferred to commercial or community area.

      I could spend my money for creation of general use network that could continue to operate in emergency but I have no motivation to make a network that could be used exclusively for emergency.

  • Some of the problems elucidated in the responses here are solvable, though of course with a cost per node penalty. For example, one could hypothesize extremely frequency- and protocol-agile nodes, capable of using a wide variety of communications methods inside the ISM bands (and, since we're talking about a wet dream here anyway) hey why not licensed bands as well? Imagine a multi-band, multi-protocol GSM/CDMA/HSPA/LTE/iDEN/WiMax/FRS/CB/amateur/WiFi/Zigbee/433MHz/infra-red/unicornfart transceiver that can
  • Think about mesh networking. How far is your wireless range? Let's say 1km with good antenna. And how big is the latency? Let's say 10 ms. How many hops does your packet need to get to the target? How much latency is acceptable?
    You won't get a usable network without cables.

    And getting 1% of frequency spectrum ... globally? Do you think all countries use the same allocations?

  • The math and physics _do_ restrict what is possible. There are limited frequencies available and bandwidth requirements limit what is usable and by how many. Mathematics (specifically information theory) quantifies the limits on the exchange of information and performance in noise.

    In a vacuum, in the absence of any electromagnetic noise, in the presence of infinite number of frequencies, with error-free 1-bit encoding of all information, and a limitless supply of free energy to power transceivers, then va

  • Well, let us imagine for some time that we have unlimited WiFi spectrum. But let's assume that the dipole antennas give maximum 250 meters. So in order to traverse Moscow (Yes, I said Moscow!) (about 25 km in diameter according to Wikimapia) you need 100 hops which require all equipment to not only work but to be placed in good high places. The ping times also would be quite.....

    You could install a 20dB dish to access a local mesh router and it would give you about 2.5 km of distance. But it does NOT solve

  • Check out FreedomBox, an open source hardware & software solution under development

    https://www.freedomboxfoundati... [freedomboxfoundation.org]

    A mass mesh network is one of the few methods society can ensure the tyranny of centralization does not continue.

    https://www.forbes.com/sites/r... [forbes.com]

    A solution to congestion is forming nodes with polygonal faces, each face mounted with it's own independent antenna, thus enabling more broad point to point communications as opposed to radial transmittance.

    • ... and each face should have a separate outdoor-class WiFi router that costs about 0.25 of average monthly income. But you increase antenna gain 4* giving distance only 2*. 500m instead of 250m are not a solution. The problem of only 4 separate 2.5 GHz channels (1 5 9 13; 3 channels in USA) is secondary.

  • This effort would be exciting and I would be game to participate and help build it out.
  • Australia.
    New Zealand.

    And other examples where it's not a mesh any more...

  • > Is this feasible?

    Technically feasible, yes I think. Imagine a weatherproof box combining a $5 solar cell and a $5 tiny linux computer operating as a mote repeater and open wifi access point.

    Place one on each utility pole running out and around the rural areas. Place one on the roof of every home in the burbs. Homeowner can provide an internet gateway if they choose.

    > Would it amass enough volunteers, advocates, and enthusiastic users?

    Unlikely. The stakeholders mentioned have already done so much. Th

  • Telstra look to be attempting this with Air. (using a combination of dedicated WIFI and guest networks from their ISP clients) DOesn't seem to have taken off enough. https://www.telstra.com.au/bro... [telstra.com.au]

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