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SPWCN/Section2.2

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2.2 Technological features: greater flexibility, resiliency, autonomy

At the technical level, the main benefits of WCN come from their flexibility and resiliency, but also from their grassroots community-driven and decentralized design, in order to foster user autonomy.

a) Network flexibility and resiliency: Given the considerable investments required to set up an independent network infrastructure, and the costs of purchasing wholesale access to last-mile landline networks from commercial operators, many grassroots community networks have decided to operate via wireless technologies, setting up network of peers sharing radio signals. Most of their network infrastructure consists of wireless radio equipment: Wi-Fi routers and antennas strategically distributed at different locations so as to maximize coverage. As a result, they can often provide a service of better quality than that which is generally available from commercial alternatives.

With regard to mesh networks, given their low-cost and highly flexible infrastructure taking advantage of users’ terminal equipment, they have historically been deployed in areas with little or no pre-existing network infrastructure, mostly in Africa. But mesh networks have also been deployed in countries where telecommunications infrastructure does exist, but is simply not affordable for lower-income households. In the American city of Detroit, where a mesh network is currently being deployed, the inhabitants could not afford to pay for an Internet connection. The mesh network—which relies on the Commotion open source software kit—builds upon existing human and hardware resources to deploy and maintain a community network with almost no upfront investments. In a European context, CMN are even known to provide better service than commercial alternatives, especially when used with high-speed landline infrastructure. For instance, Guifi.net, which began as a Do-It-Yourself wireless network intended to provide local radio connectivity to undeserved areas devoid of decent broadband Internet access, is now expanding its infrastructure by rolling out physical fibred optic cables so as to beef up the speeds delivered to rural areas in Catalonia, which so far had not been considered sufficiently profitable by mainstream ISPs.

In terms of flexibility, the main technical advantage of mesh networks are their dynamic routing protocols (e.g B.A.T.M.A.N., OLSR, Cjdns, Babel or BMX), which define the rules for transmitting and circulating packets throughout the network: as the network evolves—with new relay nodes appearing, others disappearing, and some merely changing their location—it automatically reconfigures itself according to the availability and proximity of bandwidth or storage.

This feature allows mesh networks to grow organically with minimal coordination and give them maximum resiliency: with mesh topology, there is theoretically no sensitive points (or single points of failure) to jeopardize the functioning of the local network. In practice, mesh networks are very resistant to network failure or interference since they constantly reconfigure themselves by establishing ad-hoc connections between any device at range. Even if a particular node is down, dynamic connections between nodes enable packets to travel through multiple routes, relayed from one node to another until the final destination is reached. Hence, to the extent that the network is dense enough and that many users operate as relay nodes, the only way to shut down the network is to shut down every single node it is made of.

This resiliency explains why a variety of mesh networks have been deployed in areas affected by natural disasters and impoverished communities where the basic communication infrastructure has been severely damaged or degraded. For instance, in the face of the damages caused to Haiti’s communication infrastructure by the 2010 earthquake, the Serval project was launched in Australia with the objective to create a disaster-proof wireless network that relies exclusively on the connectivity of mobile devices. Similarly, in the US, the Red Hook wireless network had formerly been deployed in Brooklyn (NY) for the purposes of providing greater resiliency and community outreach. In the midst of recovery from Hurricane Sandy, the network became extremely useful: thanks to mesh network technologies, rescue teams and local inhabitants could quickly expand the mesh network in spite of the damages incurred by the conventional infrastructure of communication (New America Foundation 2013).

Yet, despite these advantageous features, the deployment of CMN is not devoid of problems. Common issues range from the lack of infrastructure, to excessive packet loss resulting from transmission errors and slow bandwidth rate. These difficulties (many of which might eventually be overcome with the progressive refinement of mesh networking technologies) explain why some communities prefer to achieve similar goals by deploying self-managed communications networks through a more manageable and more centralized network structure, such as the one deployed by Tetaneutral.net.

b) User autonomy: Another distinctive feature of WCN—both mesh and non-mesh—relates to the commitment of grassroots community networks to promote users’ autonomy and fundamental rights to communication and privacy. As opposed to commercial ISPs blocking certain ports and censoring websites or content, most community networks are intended to protect net neutrality. In several countries, small community networks are usually not affected by censorship orders issued by courts against illegal online content. In France for instance, the state has to compensate ISPs financially for the cost incurred for blocking websites. As a result, prosecutors make the choice of focusing on the few large commercial ISPs with the biggest market share. WCNs’ commitment to fostering human rights is also reflected by the light-touch approach to logging users’ communications and sometimes their refusal to abide to legally mandated data-retention requirements imposed on traditional ISPs.

User autonomy and self-reliance is maximal when WCN are apprehended not just as part of the wider Internet but as autonomous local networks (or Intranets), allowing users to share information with other users connected to the same community network. In this regard, to the extent that they do not require centralized administration to operate, mesh networks’ flexible topography make them especially fit for deploying flexible and autonomous peer-to-peer radio networks. In the town of Sayada in Tunisia, an experimental mesh network has recently been deployed to operate locally, separate from the open Internet. The aim is to provide residents with an improved communication infrastructure, enabling them to freely and more securely communicate with each other, without having to rely on any third party ISPs. Local mesh networks also enable users to escape from the ubiquitous and pervasive surveillance that is occurring on the global Internet, as a result of privacy-intrusive practices undertaken by traditional online operators. In particular, given the lack of a central authority regulating access to the network, it is difficult for anyone to assess the real identity of users connected to these networks.

That being said, the resistance of mesh networks to surveillance and repression should not be over-hyped, as it is sometimes the case in media reports. ‘Devices operating in any wireless network—including mesh networks—use a radio transmitter that can always be located by triangulation’, notes a member of Freifunk (Mr. Juergen Neumann, pers.comm., 26 March, 2014). Besides, even with highly distributed networks, traffic can always be monitored. As Professor Edward Felten (2014) writes, ‘as soon as an adversary connects to your network, or your network links up to the Internet, you’re dealing with the same security and privacy problems you would have had with an ordinary connection.’ Thus, in spite of their benefits, in no way can local community networks replace proper encryption techniques. Their primary advantage in times of crisis is the fact that they provide community with the means to communicate independently from the central command of governments and traditional operators. They enable citizen to organize (politically or otherwise) even in the eventuality that the established powers activate the so-called ‘kill-switch’ and shut down communications networks in a given area (Hasan et al.), as has occurred in Egypt and Libya during the 2011 Arab spring, and as has even been considered in the US (Ackerman 2011), among other instances.

l'ultima modifica è del 2015-02-15 21:24:30, fatta da isi