Sending and receiving data can be difficult for people on the move, especially when they travel out of the range of a stationary wireless base. Enter “ad hoc networks,” in which radios communicate directly with each other–no central base station required.
Prithwish Basu, a scientist at BBN Technologies in Cambridge, MA, has developed algorithms that dramatically reduce the chance that a wireless network will drop connections or fail, all while decreasing the energy consumed by battery-powered radios. The algorithms will work for networks of sensors, for people carrying mobile computers, or even for groups of robots with onboard radios.
The U.S. Defense Department is interested in testing these designs as a way to help keep soldiers in touch on the battlefield, but Basu’s true passion is finding ways to incorporate ad hoc networks into everyday life.
TR: What are ad hoc networks useful for?
Prithwith Basu: To keep mobile soldiers in contact with one another and with command, ad hoc networking is the most attractive solution. On the commercial end, people were a little skeptical a few years ago. But sensor networks have really taken off recently. People are buying sensors and deploying them to monitor different phenomena: traffic, pollution, wildlife habitats, train schedules. So I’ve been pushing my company to look more into commercial aspects.
TR: What nonmilitary applications have you considered?
PB: When I was a graduate student at Boston University, I proposed networking parking meters. You put wireless transmitters on each parking meter in a city; then you add a sensor that can tell whether there is a car in that spot. If my car also has a transmitter and I am entering Harvard Square from one direction, I can ask my user interface for a parking space near the law school. My car will query the nearest meter, and if that one’s full, it will propagate the query until it finds a free spot, and then even reserves it, if possible. The network could also allow parking police to determine violators almost instantly. A number of undergraduates are now implementing a network based on these principles.
TR: Could the mobile-robot networks you’ve developed be useful in daily life?
PB: If you have a group of robots running the appropriate algorithms, you can program them to perform any collaborative task. Suppose you have a network of Roombas [robot vacuums] and you want to clean a … hotel floor. If one room is dustier, one Roomba would send a message to three others: “Hey, this space is very dirty, so please come over.” If your protocols are working correctly, you’ll get a distribution of [robots] that follows the dust pattern. Robots connected this way could also help with relief operations in large disaster sites.
In this video clip, Basu further explains “ad hoc” networks.