Smart Radio Challenge
California State University talked about unmanned aero vehicle telemetry link. Their challenge was the lack of available spectrum since an air force base was nearby. They used the Ettus Research USRP with GNU Radio software. The students developed their packet data handling protocol in Python as GNU Radio didn't provide it. They could tell the UAV to take images, generate FFTs, etc. The system had a phone home function in the event it lost communication with the ground. They used an amateur radio transceiver so it could display spectral parameters and used SDR for all signal processing. The challenges in using SDR for this project is the students had DSP but no SDR background. They started from ground zero. No one had experience with Python and no experience with real communication systems which required heavy faculty involvement. GNU Radio Grand Canyon was a good start but only goes so far. The project came out well with a successful demonstration at Edwards Air Force base. The next step will be to add target recognition and to implement the SDR on an FPGA by using the USRP.2
Virginia Tech talked about lessons from the 2008 and 2009 competitions. Their 2007 challenge was spectrum access for first responders. They chose the GNU Radio/USRP over the Lyrtech SFF because they already knew the USRP. The 2008 Challenge focused on first responders in areas with no comms infrastructure such as the Katrina disaster. They used a wireless ad hoc network approach for this one. The lessons from these two are:
Play to your strengths
Choices have unintended consequences such as system integration
Make a decision and follow through with it
For 2009 the challnege will be to locate a first rsponder based on a 406 MHz packetized beacon signal.
Carnegie Mellon presented on their Spectrum Sensing for Dynamic Spectrum Access. It's a Cognitive Radio network that takes a crowded network and sets up a secondary network within it. They first map the spectrum to find unused channels and then setup their own network. They used GNU Radio, a USRP, and Ubuntu to implement their sensing algorithm running on a series of "sensing nodes" which pass the results to a "learning center" which identifies the open spectrum slots. It then issues a beacon signal that other nodes can lock onto and then use a sub channel for creating the secondary network. They ran video, text messaging and voice messaging through the network.