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.
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.
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.
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.
This is only for data, no voice, right? Otherwise how would you negotiate with the other carriers/federal body to generate/register valid phone numbers?
BTW how do you handle roaming? Does the SIM card only work for your particular carrier? Or does it somehow integrate with the existing ones?
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.
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.
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).
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:
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.
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.
For a fixed amount of throughput, if I want consistent reads, I pay x dollars. If I'm okay with eventual consistency, I can pay x/2 dollars and get the same throughput.
Conflating resource usage, pricing, and consistency using a single metric (here, price) seems confusing, especially without the right metrics to guide devs.
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.
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. :)
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.
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.
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.
Definitely get in touch if you'd like to talk more! Many of our customers live in places that sound like where you live.