A police car patrols Brooklyn streets as hurricane Sandy hits in 2012. Credit:Reuters Meshnets are essentially local area networks cobbled together from router-connected wireless devices such as smartphones and tablets, powered by batteries or generators. The devices constitute "nodes" in the system, and transmit information between themselves over short distances. Some enabling software and a lot of tech savvy are required to establish a meshnet. The system is inherently wonky, limited by battery power and location. From another perspective, however, it is remarkably strong. Data zips between nodes autonomously, bypassing broken bits, and is thus "self-healing" in the jargon. It is also – and this is an aspect attractive to many – independent of big outfits such as Google. The people of Red Hook were fortunate that a mob of locals had already been busy building a meshnet. The system was sufficiently mature that the Federal Emergency Management Agency was able to hook it up to its satellite system, linking itself, the residents and the Red Cross into an effective communication matrix.

There are quite a few bits of software that can underpin meshnet formation. Some need to be hacked, and most present significant challenges if they have to be downloaded post-disaster when online stores are inaccessible. The newest and perhaps most promising meshnet-enabler on the market is a program called Commotion. Still in beta form, it is available free for developers and end-users alike, and is the product of a US non-profit group called the Open Technology Institute (OTI). Commotion catalyses the development of peer-to-peer networks running off wireless devices. Somewhere in the mix there has to be an internet connection, jacked into a Commotion-enabled router. The router then shares the bandwidth with all other nodes in the mesh, allowing communication without the need for data to pass through a central hub. Field trials of Commotion are under way in many communities, from Google-shy hactivists in Manhattan, to towns in countries such as Tunisia, where standard internet is sometimes blocked by government. "Because mesh networks are self-healing and able to route around points of failure, one of the primary-use cases we envision for mesh technology is resilience and disaster response," says Greta Byrum, OTI's acting field operations director. Digital connectivity has become absolutely central. Greta Byrum, OTI

"But disasters can take many different forms, from sudden catastrophic weather events to the kind of slow economic collapse that overtook Detroit at the end of the last century," she says. "Mesh is a technology that can give communities control over their own communications infrastructure, which is useful whether you're addressing entrenched poverty - one of the most common reasons that people don't subscribe to broadband services - or responding to a catastrophic weather event." Byrum stresses that mesh networks are not easy solutions to either catastrophe or repression. It is definitely not an out-of-the-box, plug-and-play option. Establishing a mesh requires planning, know-how, and community co-operation. Maintaining a mesh requires frequent tweaking and tinkering. To work effectively, need and foresight must first combine. To this end, OTI is currently working with residents in the town of Sayada, Tunisia, assisting them to create an autonomous meshnet that will continue to operate during government-led telecommunications crackdowns. The SayadaNet, as it's called, currently runs local versions of Open Street Maps, Wikipedia, a library and a chat server. OTI is well aware that independent communications networks aren't popular with many governments, including that of the US. Greta Byrum makes no apologies.

"Digital connectivity has become absolutely central to participation in government, culture and the economy," she says. "We must challenge any interests that limit or restrict our ability to design communications tools that truly meet our needs. "That said, the logic of creating distributed, open tools like Commotion is that they can be adopted widely by dispersed groups of stakeholders around the world, so there's no single point of control to be targeted by opposition. Like a mesh network, the distributed community of users itself reflects a unique kind of resilience." In Australia there are a few meshnets already up and running. They are mainly the province of enthusiastic geeks rather than activists. The oldest is Air-Stream, based in South Australia. First started in 2000 as a reaction to expensive and sporadic broadband services, Air-Stream is now "one of the largest contiguous metro-area networks in the world", according to Troy Vodopivic, the group's chairman. Air-Stream depends on a more solid core of hardware than a Commotion-style meshnet (a trade-off in the interests of stability, Vodopivic says), but still features multiple autonomous routing and self-healing behaviour.

Although primarily a hobbyist organisation "comprised mainly of tech-enthusiasts, students and IT professionals who enjoy learning and experimenting with wireless network communication", Air-Stream is well aware of its potential utility in the event of a natural disaster. Vodopovic says the group has recently started working with another Adelaide-based organisation, the Serval Project. Supported by Flinders University and others, the Serval Project is seeking to establish a disaster-relief meshnet based solely on mobile phones. For Vodopovic and his fellow techies, it's an exciting development. "There is no denying that the advent of home brew infrastructure such as these are dramatically changing the way we think about communications," he says. "By shifting the control of the infrastructure into the hands of the community we are finding new and creative ways to make low-cost communications systems that have long-term benefits for everyone."