f the final product. Design patterns that the design of an SDR system, a substantial infrastructure focus on flexibility can be more readily applied to cog- is still needed to support SDR implementations. This nitive designs, from the most basic node development all infrastructure must provide basic services, such as the the way up to full cognitive networks. References 1. J. Neel, J.H. Reed and M. Robert, "A 4. E. Gamma, R. Helm, R. Johnson and J. 8. http://ossie.mprg.org/ Formal Methodology for Estimating the Vlissides, Design Patterns: Elements of 9. http://www.crc.ca/en/html/crc/home/ Feasible Processor Solution Space for Reusable Object-Oriented Software, research/satcom/rars/sdr/sdr a Software Radio," in Proceedings of the Addison-Wesley, 1995, Boston, MA. 10. M. Henning and S. Vinoski, Advanced 2005 Software Defined Radio Technical 5. A. Shalloway and J.R. Trott, Design CORBA Programming with C++, Conference and Product Exposition, Patterns Explained: A New Perspective Addison-Wesley, 1999, Boston, MA. November 2005, Orange Co, CA. on Object-Oriented Design, Second 11. JTRS Joint Program Office, JTRS- 2. T. Budd, An Introduction to Object- Edition, Addison-Wesley, 2005, 5000, "Software Communications Oriented Programming, Third Edition, Boston, MA. Architecture Specification, SCA V3. Addison-Wesley, 2001, Boston, MA. 6. J. Kerievsky, Refatcoring to Patterns, 0," August 2004, San Deigo, CA. 3. M. Weisfeld, The Object-Oriented Addison-Wesley, 2005, Boston, MA. 12. http://www.python.org/ Thought Process, Second Edition, Sams, 7. http://www.gnu.org/software/ 2003,Indianapolis, IN. gnuradio/ Chapter 2.4b Cognitive radio: The technologies required Pablo Robert and Bruce Fette 2.4b.1 Introduction 2.4b.2 Radio flexibility and capability Technology is never adopted for technology's sake. For example, only hobbyists used personal computers (PCs) More than 40 different types of military radios (not until a spreadsheet program, a "killer application," was counting variants) are currently in operation. These radios dev