Our research to date demonstrates such a team-based
coordinated-system approach. Our work in creating a CE at
the core of our radio systems is supplemented by work on
supporting technologies such as spectrum sensing and
REMs, which provide the core with environmental awareness.
Work on reconfigurable, multiband, multimode radio
hardware provides the CE with greater ability to actuate its
environment, a key characteristic of autonomous systems. By
using game theory to understand the interactions of these
autonomous agents and networking to design protocols to facilitate these interactions, we begin to address the interactions
of these new cognitive devices with each other and
with the world around them. Through early investigations of
security and verification, we help to assure the acceptance of
the new technology by both end users and regulators.
While much has been accomplished towards the
creation of CRs and CNs, there is still much to do.
Standardized interfaces between the pieces of a cognitive
system will help to facilitate the further development of
cognitive systems, much as language facilitates clearer
thought. The cross-layer nature of CRs and CNs makes the
development of simulation and emulation tools difficult; as
a result, such tools are extremely immature. A lack of
progress in analytical methods makes it difficult to clearly
understand the engineering tradeoffs faced by the designer
of a CR or CN. Robust, affordable, and flexible SDR and
software adaptable network platforms are desperately
needed to assure continued research progress.
We plan to address some of these issues and support the
continued integration of work within our team through the
creation of a CR and CN testbed. Preliminary plans call for
placing nodes throughout a new building currently under
construction on the Virginia Tech campus. Each node will
consist of a computer, a universal software radio peripheral
(USRP), and an RF front-end built around the Motorola
chip described in Section V-C. Nodes will be remotely
reconfigurable and able to run software built around any
software architecture that supports the USRP, including
GNU radio and the Open Source SCA Implementation-
Embedded (OSSIE). We believe that this testbed will be an
important key to the continued development of CRs and
CNs by Wireless @ Virginia Tech. h