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Ad Hoc Networks: A Key to Disaster Communications?

WIRELESS MOBILE ad hoc networks, also known as MANET networks, have caught the attention of researchers and technology companies that think the networks could provide help in a disaster or war zone.

These networks are made up of nodes that can send data to each other, unlike a typical wireless card or cell phone that might be communicating with a tower somewhere. By spreading the wireless nodes throughout a tunnel or on vehicles along a path, first responders can create their own networks on-the-fly as they reach a disaster scene.

“An important feature of these ad hoc or mesh networks is that they do not require the existence of any networking infrastructure in places where they are deployed prior to an emergency incident,” says Nader Moayeri, of the advanced network technologies division at the National Institute of Standards and Technology (NIST). “However, there is no guarantee of having 100 percent radio coverage at the incident site with a mobile ad hoc network unless additional steps are taken, such as deploying some stationary mesh nodes,” because the nodes must be within range of each other.

These ad hoc systems have not been widely deployed by first responders because of lack of interoperability. “It is hard to make them work with legacy equipment, including some analog radios [that] emergency responders use today,” Moayeri says.

The technology may need to be phased in, according to Dave Buster, director of product marketing at Cisco’s Global Government Solutions Group. For example, instead of getting rid of the legacy equipment, a police car might add a router and networking gear that turns it into a “branch office.” The next phase would be true ad hoc networking in which the cars could communicate with each other and send each other data and video without connecting to an outside wireless network.

As first responders start to get next-generation equipment, it will be more likely that these ad hoc networks will take off. “We know the demand is there, the need is there, and everyone who sees it gets really excited. The question is the money. And I’m not sure the municipalities have enough money to add on to their existing systems very rapidly,” says Buster.

Ashburn, Virginia-based Telos Corp.’s Xacta Secure Networks has a vehicular ad hoc network solution called Comms on the Move, which uses the BreadCrumb® by Malvern, Pennsylvania-based Rajant Corp. as its nodes (so named because the path of nodes is like Hansel and Gretel’s path of crumbs).

The system has not yet been deployed, but it has been purchased by the Air Force Central Command. The system connects vehicles within a convoy via nodes, which allows the vehicles to “talk” to each other, as well as transmit video, data, and voice. According to Xacta’s Tom Badders, any IP-based technology can integrate with it.

Although the company initially focused on the military as an end user, it is now expanding into the civil field with the Air National Guard. The product allows them not just to maintain connectivity but also to have an instant network at their final location, and it would facilitate communication with other first responders, says Badders. After the National Guard uses it, he expects the technology to catch on at the state and local levels. Badders adds that Rajant’s products have been used in the mining industry, although Comms on the Move has not yet been used underground.

Buster says that Cisco has sold some police departments off-the-shelf gear to create basic ad hoc networks with ranges of a few hundred yards. And he says routers that are being added to police cars will also provide the capability to establish such networks.

The networks will, however, take off in homeland security first and then trickle down to police and fire departments, predicts Buster. As soon as police and fire departments begin to see that the networks are saving lives, they’ll be willing to invest in the technology, he says. “We’ll turn that corner in the next two or three years.”