Do we have a failure to communicate? The future of ultra-wideband (UWB) technology

But the technology holds significant promise for applications such as wireless USB, which, as Robert Aiello points out in the concluding chapter of Ultra Wideband Systems, can readily make use of UWB’s high-bit-rate, short-range communications capabilities. Beyond cable-replacement chores, Aiello says UWB can also serve applications such as digital cameras and portable media players, for which no cable alternatives exist.

But the bulk of Ultra Wideband Systems deals with UWB technology, not applications. And given that the applications will emerge, this book provides a good overview of what UWB is and how it works.

For most of UWB’s history, it served in the military and in labs, with the term “ultra wideband” itself appearing in the late 1980s, apparently from the Department of Defense, according to Aiello. The more consumer-centric version was born on Valentine’s Day 2002, former FCC chief engineer Edmond J. Thomas reports in a forward to the book, when the FCC issued a necessary approval despite complaints that UWB would occupy 7.5 GHz (3.1 to 10.6 GHz) of already-licensed spectrum.

The book introduces UWB technology, beginning with Shannon’s theorem: C = Wlog₂(1 + S/N), which demonstrates that it is more effective to increase bandwidth, W, which is linearly related to capacity, C, than to increase power, S/N, which is logarithmically related.

The second chapter discusses regulatory requirements and the governing organizations as well as the testing infrastructure, focusing on anechoic chambers, open-area test sites (OATS), and alternative environments such as mode-tuned or mode-stirred chambers. As for instrumentation, chapter author Robert Sutton notes that time-domain instruments used for UWB measurements require large instantaneous bandwidths, while frequency-domain measurements can be made with instruments having limited bandwidths if properly staged.

Chapter 2 is the only one that focuses extensively on test, but the entire book could be said to deal with measurement in that it describes the parameters and characteristics you have to verify if you find yourself developing UWB products. Other chapters cover interference, UWB antennas, direct-sequence and multiband (including multiband OFDM) UWB approaches, and UWB MAC design. In one chapter, Naiel Askar, Susan Lin, and David Furuno of General Atomics describe the Spectral Keying UWB modulation scheme developed by their company; the advantage, they write, is the technique’s scalability.

It remains to be seen which techniques will be essential to UWB’s success as developers “focus on simplifying use, streamlining costs, and staying ahead of advancing data rates,” according to Aiello. This book serves as a good foundation on which developers can build. (Note: The publisher is owned by Test & Measurement World’s parent company.)