Microwave Journal
www.microwavejournal.com/articles/4440-uwb-technology-closer-to-ratification

UWB Technology Closer to Ratification

October 1, 2003

In order to gain acceptance and grow, a technology needs to be standardized by the industry, enabling equipment and peripheral manufacturers to create, distribute and sell compliant products. According to ABI Research, ultra-wide band (UWB) wireless technology took a step closer to gaining broader standards and specifications, paving the way for much more expansive distribution possibilities for the technology.


UWB is a signal that occupies more than 500 MHz in the 3.1 to 10.6 GHz bands. The Federal Communication Commission (FCC) approved the commercial use of UWB technology in February 2002. Until then, UWB was mainly used for military niche imaging and radar applications. The FCC's decision recently approved indoor UWB emission levels below that specified by the FCC's Part 15 limit. In the past, UWB has been defined as a technique of encoding information impulses, modulated with amplitude, phase or position. The FCC has changed the definition of UWB to include any technology - even those that are not pulsed-based - that utilize more than 500 MHz of spectrum within the emission levels.

At the IEEE conference in San Francisco on July 25, 2003, about six different proposals were presented to select the UWB Physical Layer (PHY) specification. The final vote on this was due in September 2003. The multi-band OFDM coalition is one of the key players pushing for a multi-band protocol for the PHY specification. This coalition consists of large corporations including Intel, Panasonic, Mitsubishi, Philips, Samsung and Texas Instruments. The remaining five proposals are from XtremeSpectrum, STMicroelectronics, Parthus Central Communications Research Lab and the University of Minnesota. For one of these proposals to be ratified as a specification, 75 percent of all votes are required. The multi-band OFDM coalition might be able to engineer a huge share of votes; then again, CDMA proponents XtremeSpectrum and STMicroelectronics might thwart that with their efforts to garner support of their proposals. If none of the proposals manages to get 75 percent of the vote, then the situation comes to a stalemate - which might be good news for the proposals that are second and third in the race. Then the key leaders in the race will pursue multiple solutions simultaneously and the market will decide on the future of a particular solution. This has happened in the past with respect to IEEE 1394, USB and Bluetooth.

According to XtremeSpectrum, the multi-band OFDM coalition's proposal contains frequency-hopping provisions, which could increase the power consumption levels, ultimately reducing the range of the UWB-enabled device. The FCC has laid down clear restrictions on power consumption levels and spectral map usage. XtremeSpectrum had to launch its second generation of silicon by September 2003. The company's solution might be a cheaper solution compared to that of OFDM, but that may not be the only deciding factor in selecting a particular proposal. There could also be a lot of hand twisting and inside politics before the final voting. Recently, TI, which was pushing for its own proprietary solution, joined hands with the likes of Intel, Samsung, General Atomics and others to form the aforementioned multi-band OFDM coalition. OFDM has been adopted for several technologies in the past, such as ADSL, IEEE 802.11a/g, IEEE 802.16a and so forth, and has an inherent robustness against narrowband interference; OFDM is also considered to be ideal in multi-path environments.

No matter which proposal(s) come(s) out as a winner, UWB technology, due to its high rates over short distances, could play a monumental role in the future of wireless networking. Once UWB technology reaches maturity, most of the future camcorder, still digital cameras, high resolution printers and scanners, DVD A/V players, HDTV and many other high end digital devices will be equipped with UWB technology. Contrary to most of the fears from WiFi proponents, UWB will compete with IEEE 802.11x technology only where high data rates are required over short distances. If the manufacturers and buyers have products that comply with the prevailing standards and specifications, the technology has greater chances of success.