Another CR testbed introduced is the Radio Open Source System (CROSS) [19]. CROSS is a research project carried out at [1] which aims to develop open source CR architecture. The objective here is similar to other testbeds such as BEE2 which is to develop a distributed and modular system that provides portability and interoperability between modules developed in different programming languages. CROSS uses socket connection for inter-component communication that allows distributed system components to be developed in a language-independent manner.

[1] http://wireless.vt.edu/