May 7, 2004 By Kris Middaugh
Now imagine the average mesh network as a swarm of bees, and take that same stone -- heck, take 100 stones -- and hurl them into the buzzing mass. You may take out a few bees -- perhaps many -- but the swarm will remain intact.
In real life, vital cell towers are susceptible to attacks and natural disasters, with long-term service interruption a near inevitability in either case.
To avoid such a situation, one Texas town replaced its existing communications networks with mesh network technology, which relies on a distributed network of devices rather than a central orchestrating device. The new mesh system provides the city with a powerful broadband network that supports high-speed data, streaming video, voice messaging and precision geo-location.
When Disaster Strikes
In addition to cell towers being ruined in a disaster, cellular service can also be overwhelmed -- problems can arise from millions of music-loving TV-viewers using cell phones to cast electronic ballots for the latest American Idol. In a more ominous scenario, overwhelmed cellular communication systems can -- and have -- imploded into uselessness during large-scale emergencies and disasters like 9/11.
It may be impractical, imprudent and perhaps even downright foolish for first responders to rely on cellular technology for data -- let alone voice and video -- transmission needs during an emergency situation.
Enter DARPA. The Defense Advanced Research Projects Agency is the government organization perhaps best known for inventing the Internet. In 1997, the agency began work to ensure better, more powerful, secure and dependable battlefield communications.
DARPA engineers created a network that requires no infrastructure, but rather exists via user-devices, such as handheld computers and mobile phones, which act as transmitters. In theory, these "mesh networks" could instantly form between as few as two users via nodes embedded in system devices, which act as relay points for any other node. This allows signals to "hop" from one device to the next instead of being routed through a central device.
The technology worked, but DARPA's heavy communications equipment limited its practicality. So the military awarded a private company, ITT Industries, a contract to improve the technology's user-friendliness.
In January 2002, MeshNetworks Inc. was formed to commercialize the new mesh technology for the nonmilitary sector. The company now holds the exclusive license, patents, software and design that resulted from the DARPA and ITT Industries research, according to Rick Rotondo, MeshNetworks' vice president of technical marketing.
MeshNetworks reduced the technology to a single chip, which Rotondo said took more than two years and $20 million. But the investment seems to be paying off as the first citywide deployment of its technology nears completion.
Mesh Meets Needs
Garland, Texas -- a Dallas-area suburb with a population of more than 200,000 -- has almost finished deploying a mesh network across its nearly 60 square miles. Like many jurisdictions across the country, Garland IT professionals scrambled to replace their cellular digital packet data (CDPD) system. Law enforcement relies on this specification, which supports wireless Internet access and other public packet-switched networks -- but the FCC is phasing it out this year.
Along with their CDPD system, Garland officials were also having coverage problems with an aging simulcast radio system. Darrell McClanahan, Garland's telecommunications manager, wanted a solution to resolve both wireless problems.
McClanahan said he liked the idea of mesh networks, but had to be sure the mesh network could keep up with city employees.
"One of my concerns was in combining both voice and data -- would I provide throughput at highway speeds?" he