Technology Review has a story on MIT’s Roofnet, a mesh networking project creating self-organizing wireless networks with cheap Linux computers and Wi-Fi cards.
Each computer and roof-mounted antenna at students’ apartments and MIT buildings is a node on the network (map). The interconnection topology is constantly changing. “We want to understand how a whole bunch of computers with short-range radios can self-configure a network, forming order out of chaos,” says computer science professor Robert Morris, who coordinates the project.
The network has now more than 30 nodes in a 4-square kilometer area surrounding the MIT campus. “We hope to reach a hundred nodes within a few months,” he says.
Each Roofnet node uses an 802.11b wireless networking card installed on a cheap PC running Linux and the routing software. A coaxial cable connects the wireless card to an omnidirectional antenna. The user then connects the PC to the Roofnet node. The total cost of the equipment for each node is $685.
Research groups at universities such as Carnegie Mellon, Rice, UCLA, and the University of Illinois at Urbana-Champaign, and at companies such as Nokia, Intel, and Microsoft are developing similar mesh systems.
Community-owned wireless networks in New York, San Francisco, Seattle, London, and other cities usually use DSL for their backbone. Mesh networks like Roofnet might provide an alternative, perhaps in combination with “last mile” wireless backbones like 802.16a.
Mesh networking has been around for a while. Nokia abandoned their Rooftop Wireless. Other mesh networking approaches include:
- LocustWorld has had moderate success across the UK. For a while in 2002, there was discussion that mesh networks could pose a threat to the future of 3G technology.
FastLine (FAQ), is reportedly the first ISP to use Mesh networking in the United States. They use MeshAP from LocustWorld. A rural town of 4,500 people, is served, according to the Shrevport Times.
- Half Moon Bay, near San Francisco, has deployed 8 to 10 Wi-Fi hot spots using Tropos network. Two of the hot spots have land-line connections to carry the data to the Internet backbone, the rest use mesh-like interconnections.
The Intel-funded Tropos 5110 is a mesh-based Wi-Fi network for outdoor installations. It can be mounted on external structures such as buildings or lampposts and is used for citywide police data communications and wireless public access.
Mesh networking may be particularly well suited where multiple portable devices are interconnected. The connected soldier could use low power UWB, for example, and hop through multiple handhelds before reaching a backbone connection.
Although no mesh networking was used, a Wireless Caravan cruised down the West Coast earlier this year. They used EPIA M-Series boards from VIA Technologies. While travelling at highway speeds, the servers streamed music via Icecast, provided anonymous FTP uploads and downloads, as well as IRC, Jabber and other communication services between the cars.
Portland has roughly 130,000 miles of unused (dark) fiber optic cable between it and Seattle, most of which was laid by telcom providers who went out of business and no longer own it. Perhaps an AP every ten miles could be relayed through mesh networks on light poles every 1/2 mile or so. Directional antennas could send 5.8 Ghz & 5.9 Ghz (Intelligent Transporation System) down a linear roadway. Handy for tracking cargo, too.
Get Homeland Security to pay for it - they’ll fund anything.
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