Center for Wireless Telecommunications
Virginia Tech
Blacksburg, Virginia 24061-0111
Phone 540-231-5096 Fax 540-231-3004 e-mail bostian@vt.edu
We present the design of a rapidly deployable backbone communications system for disaster response. Although work on the system began in 2000, it is intended for disasters like those that occurred on September 11, 2001. It illuminates the disaster site with RF that supports high-capacity (100 base T or Gigabit Ethernet) links to the outside world. Operating initially at 28 GHz with a 5 GHz version now under construction, it uses non-line-of-sight (NLOS) "bounce paths" of opportunity to provide coverage at shadowed locations. Since at these frequencies most building walls and terrain features are electro magnetically rough, the radio paths are highly dispersive and require careful characterization for optimum radio performance. In order to identify such paths of opportunity and study their characteristics, we developed an impulse channel sounder based on ultra wideband technology. When perfected, it will allow our system to identify the best path and set the radio parameters for optimum quality of service. Since the channels encountered in a given disaster situation may differ significantly from those anticipated or previously experienced, our goal is to use the sounder output to drive a cognitive engine that will control the radios. We present our genetic algorithm based implementation of a cognitive radio and outline our plans for implementation and testing a cognitive version of our system in the 5 GHz band.
