With growth of flat screens and HDTV on the upswing, the quest for wireless video networking has taken on greater importance. The ideal is to be able to create home networks that carry multiple channels of high quality video plus other data and voice traffic wirelessly, not just within rooms but around the home.
We have written previously (http://www.broadbandhomecentral.com/report/backissues/Report0307_6.html) about wireless video networking, and took the opportunity to meet again with Bermai and ViXS at CES. Both companies are developing chip technologies to facilitate wireless video networking. They are both targeting consumer electronics companies that want to sell portable flat-screen TVs.
Both Bermai and ViXS aim to support high-definition television and both are using 802.11a as the base standard in the 5 GHz spectrum; they take very different approaches to maximizing bandwidth utilization and maintaining video quality in the presence of interference and other bandwidth users.
We first interviewed (http://www.broadbandhomecentral.com/report/backissues/Report0205_5.html) Bermai's CEO and President Bruce Sanguinetti almost two years ago, and were delighted to meet him in person at CES. Bruce and his team gave us an update and showed us a demonstration of Bermai's technology.
Bermai is using two approaches to get high-quality video. The first is MIMO -- using multiple antennas at both the base station and the subscriber station to increase the performance of the wireless link. The second is implementing the 802.11e draft standard for QoS to assign higher priorities to video streams.
Our attitude as we approached the demonstration was skeptical. Having run many tests of wireless technologies in our own home, we understand first-hand the impacts of walls, floors and disturbances in the environment (like people walking around). Their impressive demonstration showed two simultaneous high-definition video streams, a standard-definition stream and file transfer between two PCs -- all running in the same 802.11a channel. The base station was at one end of a hotel room, and several of the subscriber stations--including a high-definition station--were in another room with two walls in-between. We could see the effect of the QoS -- the file transfer data rate varied over time while the video kept operating properly at a constant rate. We left the demonstration being more optimistic that it will be possible to get high quality wireless video using approaches like those Bermai is employing.
We first interviewed (http://www.broadbandhomecentral.com/report/backissues/Report0209_6.html) ViXS more than a year ago and met with CEO Sally Daub at CES last year. This year we met at CES with Director, Corporate Marketing Ciricia Proulx for an update and demonstrations.
ViXS is using two different approaches to get high-quality video. Their Matrix chip uses two 802.11a channels simultaneously to address the "near/far" problem - when running 802.11 in a a single channel, the far subscriber can easily hog the channel and leave insufficient bandwidth for a closer subscriber; it also includes support for multiple antennas to increase receiver sensitivity. The Matrix chip is typically built into a wireless base station, while subscriber stations use standard low-cost chips.
The second approach--embedded in the XCode II chip--is to adjust the bit-rates, resolutions and formats of multiple MPEG video streams in real time, adapting each stream to changing network bandwidth while maintaining the video frame rate. We wrote about the original XCode chip in 2002; the new XCode II chip can encode up to four analog audio/video streams, transcode between different digital video formats, transrate to adjust speeds, and convert between different video resolutions.
ViXS has announced design wins with Daewoo, Arcadyan (a Philips/Accton joint venture) and Toshiba. At CES, ViXS and Daewoo showed Daewoo products based on both ViXS chips. ViXS also demonstrated the use of the XCode II chip to transcode/transrate MPEG2 video streams for playback on a low-resolution PDA screen.
We will continue to watch how consumer electronics manufacturers embrace the very different ideas in the Bermai and ViXS chips, and expect to see a variety of consumer products based on these chips later this year.
Note: Press reports indicate that Magis Networks, another player in the video networking space, has entered Chapter 11 bankruptcy and is auctioning off its remaining assets. Unlike Bermai and ViXS, Magis had been developing a proprietary technology operating in the same 5 GHz spectrum as 802.11a.