Another testbed for developing cognitive engines is the Berkeley Emulation Engine 2 (BEE2). The BEE2 system is a FPGA-based computing platform designed to be modular and scalable. Its software design methodology targets a wide range of high performance applications one of which is Cognitive Radio Systems [1]. The FPGAs employed are Xilinx FPGAs (Virtex II Pro 70). The platform has been used to practically carry out a number of scenarios at the physical and link layer
levels in [2]. The motivation was to validate various sensing algorithms to prove non-interference to licensed users while evaluating their performance. For trials, the 2.4GHz spectrum is chosen since a wide range off-the-shelve radio
equipment is available.

[1] BEE2 (http://bee2.eecs.berkeley.edu/)

[2] S. M. Mishra, D. Cabric, and C. Chang, “A real time cognitive radio testbed for physical and link layer experiments,” in
IEEE International Symposium on New Frontiers in Dynamic Spectrum Access, 2005, pp. 562–567