A Quick Way to Build a Wireless Network
Local governments are using mesh networks to stay connected during outages, offer high-speed Wi-Fi and breach the digital divide. But it’s not perfect.
What do Sayada, Tunisia, and Red Hook, Brooklyn, have in common? At first glance, not much. One is a fishing town on the Mediterranean Sea. The other is a waterfront neighborhood in an industrial section of America’s largest city. But both are using a networking technology that is cheap, relatively easy to set up, and remarkably resilient and secure.
Called a mesh network, the technology lets users connect directly to each other rather than through a central hub. For the citizens of Sayada, that means they can create a community network free from government surveillance or interference. For residents of Red Hook, the local mesh network helps them stay connected during power outages.
Of course, mesh networks aren’t new. They’ve been operating in Europe for years. They are, however, relatively new to the U.S., where they are just starting to catch on. In Detroit, where some neighborhoods don’t have access to broadband, mesh networks are seen as a low-cost solution to the digital divide that exists there. And for many local governments, mesh networks are a relatively simple way to offer high-speed Wi-Fi. Ponca City, Okla., has adopted mesh as a means of delivering free wireless broadband to all of its 25,000 residents.
Most wireless networks operate using a hub and spoke layout -- basically, a central broadcast tower links to users like spokes on a wheel. With mesh networking, “envision a fish net,” says Georgia Bullen, field operations technologist for the nonprofit Open Technology Institute. “Every device on the network is part of the network.”
This design avoids any single point of failure (a problem in Red Hook during Hurricane Sandy in 2011), and it allows the network to bypass obstacles, such as hills or buildings, using different signal paths. If a local coffee shop, for example, has a wireless router that’s part of the mesh network and wants to turn off its device when it closes at night, the network bypasses the coffee shop. When the shop turns its router back on in the morning, the network automatically reconfigures to run through the coffee shop again.
Mesh networks can start small, with just a handful of devices, but can easily grow as demand picks up. “Think of mesh networks as infrastructure lite,” Bullen says. “It’s similar to installing bus rapid transit versus an underground subway system. It’s something that can be put up quickly, even moved to another location if it isn’t working well.”
Grassroots community groups have shown the strongest interest in using mesh networks, but cities and towns should consider them too. It’s a way to provide citizens access to the Internet in hard-to-reach places, such as city parks and urban corridors where buildings might block traditional Wi-Fi signals.
Mesh networking does have some technology challenges and limitations, though. Every router that forms the backbone of the network must have an unobstructed view of another router in order to complete the connection. Most neighborhood mesh networks are designed to operate at rooftop level so that trees or other buildings don’t block the signal as it travels from one router to the next. Communications can also get slow if signals have to make multiple hops from one router to another; costs can escalate if the size or scope of the network grows significantly; and putting together a small network can be time consuming. Community networks that rely on volunteer help often underestimate the amount of labor needed to set it up.
Despite the drawbacks, the future for mesh networks looks bright. The demand for wireless access, particularly in dense and low-income urban areas, continues to grow. And as climate change brings more unpredictable weather, mesh could become a critical way to keep citizens connected to vital services and make communities more resilient.