Electronic Design

Whatever Happened To UWB?

Is UWB dead? No, but with its limited applications and competition from the forthcoming 60-GHz wireless products, it is in for a fight for its life.

There was a time when Ultra-Wideband (UWB) wireless was a hot topic. Yet, the last couple of years have been quiet for UWB. Several chip companies, like T-Zero and WiQuest went away, while others seem to be regrouping in an effort to figure out their next move.

Staccato and Artimi merged, retaining the Staccato name, and both CSR and Samsung also have UWB chips but no activity has been noted. The only companies that appear to be active are Alereon and Wisair. In any case, here is an update on this interesting wireless technology.

UWB  wireless technology is defined as having a signal bandwidth  over 500 MHz, or at least 20% of its center frequency. In the U.S., UWB operates in the 3.1- to 10.6-GHz range. It began about 10 years ago as an impulse radio technology that spread a high-speed digital signal over a huge bandwidth. That technology did not work as well as expected and was ultimately replaced by an orthogonal frequency-division multiplexing (OFDM) version offered up by a large group of semiconductor vendors.

No one emerged victorious in the battle to develop a single UWB technology per the IEEE 802.15.3a standards, so the OFDM crowd broke off, founded the WiMedia Alliance, and developed a pretty good standard that was widely adopted by a half-dozen or more companies that made silicon in its support. The ultimate target was the wireless transfer of video between consumer electronics boxes and other digital data over short distances.

The range and speed never lived up to the projected 10 m and 480 Mbits/s, and the idea of compressed video was unacceptable to some. So, most companies backed up and set off on  another path, promoting UWB as the wireless USB. The USB Implementers Forum adopted that idea as a standard, so UWB is mainly used to replace USB cable.

As of March 2009, the WiMedia Alliance transferred its technology to the USB Implementors Forum and the Bluetooth Special Interest Group (SIG). Since then, not much has happened. The Bluetooth SIG has indicated that it would not use UWB as a future speed enhancement to Bluetooth Personal Area Network (PAN), seemingly because of intellectual property (IP) issues with WiMedia Alliance members.

Instead, the SIG announced its 3.0 technology, which uses 802.11 technology to achieve a modest 24-Mbit/s data rate at up to 10 m. That does not seem to be widely used. Apparently, the Bluetooth SIG is focusing on 60-GHz wireless approaches as a future upgrade for its PAN.

However, despite missed opportunities and rapid development of competing technologies, UWB is not dead. I spoke recently with Alereon and Wisair about their operations and plans.

Wisair’s VP of marketing, Asaf Avidan, told me about the company’s  plans to promote its chips as the heart of a laptop-to-HDTV wireless technology (Fig. 1). More than 10 consumer electronics companies are already offering products that connect laptops to big-screen TVs using Wisair’s WSR601 single-chip UWB radio with on-board USB connectivity. Wisair and its end-product vendors are promoting this approach as the “killer app” of wireless USB. I was skeptical at first but I can see how Wisair, and Alereon, have arrived at the same place. It is a totally cool application that could become addicting.

The product is a small dongle that connects via a laptop’s USB port. A bit larger A/V adapter connects to an HDMI port on the flat-panel TV. A special display mode is provided to allow the content viewed with the laptop to be different from the information displayed on the TV, meaning you can continue working while your kids watch a movie or television show online. 720p HD video is supported. These products use Wisair’s UWB module (Fig. 2).

Keep in mind that the Internet has become the number one source for video and other types of content. Watching online video outranks many other online activities today. Television channels, news clips, and a myriad of video clips, offering pure entertainment to product user guides, are all available at popular online sites such as YouTube, Hulu, Netflix, and Amazon Video.

Another key factor is that laptop PCs have become more popular than desktop PCs. Laptop screens are small, and netbook screens are even smaller, which makes it more difficult to watch content for a long period of time or share content with others. In addition, laptops store personal information such as photos from digital still cameras, clips from camcorders, and more.

To complement that, big-screen HDTVs have become more affordable and very popular. With their digital interfaces, flatscreen sets are commonly found at homes and offices alike, enabling new types of content, and new ways for it to be displayed, as opposed to traditional TVs displaying information from  cable, satellite, or terrestrial broadcast sources. Given those facts, it is easy to see how this app could become really popular.

Wisair isn’t the only company that thinks so. At a meeting with Eric Broockman, Mike Krell, and Charles Dittmer of Alereon, I saw a demonstration of the company’s latest UWB apps. They also showed me a system for wirelessly connecting a laptop to a large-screen HDTV. A wireless dongle plugged into the laptop talks to a base unit connected to an HDMI input on the HDTV. Compressed video carried via UWB is displayed on the big screen. The laptop can access video via its Wi-Fi or 3G cellular connection while  the video is streamed to the TV. It is an impressive application that could see some consumer interest. A consumer end product based on this approach, using Alereon AL5000 chips, was announced at the 2010 International Consumer Electronics Show (CES) in Las Vegas last month. A reference design is available.

Alereon’s chips are also part of Toshiba’s Dynadock U Wirelesss USB docking station and are embedded in Dell’s new Latitude Z notebook PC. The Alereon AL5000 series chips show up in a handful of other USB-related wireless products.

Alereon

Wisair

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