TABLE OF CONTENTS "The telecommunications market is nearly 1 trillion dollars per year. With a market of that size, even a few percent is large enough to be an interesting business." [1]
The ability to improve spectral efficiency, enhance network efficiency, and serve the telecommunication user the purview of cognitive radio (CR) is an application that adds significant value to the telecommunication market. This book has provided a detailed review of the major technologies that are well understood and stand ready to enable CR. This concluding chapter recaps those technologies, and reviews the current state of the art. This chapter stitches together the pieces, showing how they intermesh to build CR systems, and then presents remaining problems that must be solved.
As stated in Chapter 1, we are taking the perspective that the CR is a radio that is sufficiently intelligent to: (1) aid spectrum efficiency, (2) aid the radio networks and network infrastructures, and (3) aid the user. At this time, no "cognitive" radios are in production, although several are in development, prototyping in several laboratories is an ongoing activity, and several international testbeds have begun.
Chapter 2 presented the regulatory perspective regarding CR. The regulatory climate is positive and is encouraging the demonstration of CR technologies. US research and development (R&D) organizations are providing support for such demonstrations. In the United States, 10 MHz has been provided for experimental evaluation testbeds...
