What's needed is a self-powered router that can take the heat.
S&T is developing a tiny throwaway router, measuring one inch square by inch thick, that's waterproof and heat-resistant up to 500 F. The Wireless Intelligent Sensor Platform for Emergency Responders, or WISPER, contains a two-way digital radio, antenna, and 3-volt lithium cell.
Here's how it works: Each firefighter enters a burning building with five routers loaded into a belt-mounted waterproof canister. If a firefighter steps behind concrete or beyond radio range, the base station orders his canister to drop a "breadcrumb." The dropped routers arrange themselves into a network. If a router accidentally gets kicked down a stairwell or firehosed under a couch, the WISPER network will automatically reconfigure.
To an embattled firefighter, a handful of these smart "breadcrumbs" could spell the difference between life and death.
To extract the most life from the router's tiny battery, WISPER's designers turned to a simple, low-power communications protocol, ZigBee. ZigBee is tortoise-slow by design; it trades speed for battery life, telegraphing no more than 100 kilobits per second (kbps)a rate that's more than 99 percent slower than WiFi.
"Throw in smoke, firehose mist, stairwells, and walls, and you're down to maybe 10 kbps. But that's fast enough to tell an incident commander the whereabouts (via GLANSER) and health (via PHASER) of every firefighter in the blaze," explains Jalal Mapar, WISPER's project manager in S&T's Infrastructure Protection and Disaster Management Division. "We're not streaming video that needs a lot of bandwidt
|Contact: John Verrico|
US Department of Homeland Security - Science and Technology