UWB represents a challenge that the test-equipment development community has not faced before.
Test-equipment developers are to be applauded for their knack of anticipating the industry's high-frequency measurement needs. In spite of the plethora of wireless-communications formats and standards, including the various flavors of cellular radios, Bluetooth, and the many configurations of wireless local-area networks (WLANs) to name a few, suppliers of test solutions have either been ready with targeted instrumentation or, in the worst case, responded quickly to an emerging measurement need.
Even when wireless standards have changed directions, as in the case with WLANs, test engineers have been able to follow the most erratic product-development paths—often by participating in standards-development committees—and be ready with practical solutions when the market demanded them. Sometimes these solutions have come in the form of dedicated test equipment; sometimes they have been made available as modules or software "personality" upgrades for existing equipment.
When searching for test equipment for one of the newer emerging wireless-communications formats, however, the solutions are more approximations than exact fits. That emerging technology, ultrawideband (UWB), certainly represents a challenge that the test-equipment development community has not faced before and is actually closer to requirements typically established by the surveillance community. Two years ago, the US Federal Communications Commission (FCC) gave its preliminary blessing to the use of UWB technology (by means of its First Report and Order issued on February 14, 2002), with the promise to monitor its potential interference effects on existing, traditional users of RF signals, such as cellular telephones, Global Positioning Systems (GPS), and WLANs. The FCC (www.fcc.org) actually established three different groups of UWB-based products: imaging systems (such as ground-penetrating radars), vehicle radar systems, and communications and measurement systems. This last group, which is of greatest concern to existing standards and unlicensed users of RF energy, has been restricted to the frequency band from 3.1 to 10.6 GHz.
Although debate continues, with or without the IEEE, on just how to implement an industry-wide standard for unlicensed UWB communications, test-equipment developers are currently stymied as to how to evaluate UWB gear. Most test tools are designed for relatively narrow channels, even as much as 20 MHz in wideband CDMA systems. But capturing several GHz of bandwidth in one shot represents a whole new problem. Still, test-equipment developers have never ceased to amaze when meeting new challenges, even one as daunting as this.