Interesting discussion of this new 60 GHz in-room link people are talking about. Looks like UWB has limited spectrum in Europe and none in Japan, except for experimental purposes. But it also looks like UWB can do uncompressed video, in a scheme called wirelessHDMI.
Bert ------------------------------------------ Digital living room duel Group tuning 60-GHz radio to vie with ultrawideband and wired alternatives Rick Merritt (11/06/2006 9:00 AM EST) URL: http://www.eetimes.com/showArticle.jhtml?articleID=193501686San Jose, Calif. -- One of the most promising wireless technologies in the lab has jumped into one of the most hypercompetitive markets in electronics. Last week, six top consumer electronics vendors formed the WirelessHD group to define 60-GHz radios that could carry uncompressed high-definition video across the living room at a roaring 5 Gbits/second.
The group--comprising LG, Matsushita, NEC, Samsung, Sony and Toshiba--will deliver a specification this spring for links reaching up to 10 meters. The nascent technology will have to compete with established wired links such as 1394 FireWire and the High-Definition Multimedia Interface (HDMI), as well as 802.11n and multiple flavors of ultrawideband.
"It is completely un- predictable at this point whether one technology will win or not, but I don't think that will happen," said Craig Mathias, a wireless analyst at Farpoint Group. "We may see some answers as early as CES [the Consumer Electronics Show] in January."
Commercial and academic researchers have long pursued the promise of 60-GHz radios, which have access to as much as 7 GHz of unlicensed spectrum but are notoriously difficult to implement. In its favor, the WirelessHD group has the backing of startup SiBeam Inc. (Sunnyvale, Calif.), founded by UC Berkeley researcher Bob Brodersen, a leading pioneer of CMOS radio. The group will need all the brainpower it can get; the technology faces challenges ranging from designing, simulating and testing ultrafast circuits to building highly accurate and adaptive antennas.
On the business side, the plan to carry uncompressed digital high-definition video faces scrutiny over security from Hollywood. WirelessHD has yet to hammer out a business model or make a decision on royalties.
The propositionBandwidth is the trump card for 60-GHz radios, which will not be the smallest, cheapest or lowest-power options on the home network. The group has seized on the value proposition of carrying uncompressed high-definition video at resolutions up to 1,920 x 1,080 progressive scan, with latencies ranging from 5 to 15 milliseconds.
WirelessHD chairman John Marshall said TVs, DVD players and other high-def gear could actually provide better resolution, with less latency and cost, by using 60-GHz radios rather than ultrawideband. That's because the typical 480-Mbit/s bandwidth of UWB requires recompressing packaged or broadcast video, forcing OEMs to put expensive encoders and more RAM into their systems, losing video content and adding latency in the process.
"I have seen the difference between lossy twice-compressed content and HDMI uncompressed content, and my eyes aren't golden," said Marshall.
The WirelessHD group is developing a complete spec for 60-GHz products that spans everything from the physical layer to the application layer, though Marshall would not provide details about the work in progress. The spec is for "predominantly point-to-point" connections, but it does include a back channel running at less than 100 Mbits/s, he said.
With a 10-meter maximum range and no penetration through walls, 60-GHz radios have no immediate road map to becoming the much-desired whole-home net. The technology can be bridged to any existing home net, though the spec will not address bridging specifically.
The industry in general could deliver 60-GHz radios in about a year that consume 5 watts or less and carry a small premium over wired links, SiBeam's Brodersen predicted. They are likely to be packaged in a 1-inch-square module sized to accommodate a directional antenna array, he said.
Business challengesThe WirelessHD group faces a diverse handful of business challenges for handling security, royalties, regulations and standards.
Marshall said the 10-GHz spec will reference a number of existing content protection technologies, including Digital Transmission Content Protection (DTCP) and HDMI's High-bandwidth Digital Content Protection (HDCP). But Hollywood may want to see additional protections.
"There will be discussions about mapping DTCP to this new interface that could put some new requirements on it," said Brad Hunt, chief technology officer for the Motion Picture Association of America. "We have begun discussions with Intel about the use of HDCP on broadband wireless. But I don't have a big concern about [WirelessHD]."
The WirelessHD group is still debating whether to charge royalties. It's a "big issue" that "requires significant discussion and consideration," Marshall said, adding that arguments can be made for both models.
On the regulatory front, 60-GHz radios are "not bogged down with a lot of regulatory problems, like UWB is," said Bob Heile, chairman of the IEEE 802.15 Working Group on PANs and chairman of the ZigBee Alliance.
The WirelessHD group can use unlicensed spectrum in the 57- to 64-GHz range in the United States, where transmit power up to 10 W is permitted. In Europe and Japan, it will use the 59- to 66-GHz bands.
By contrast, UWB has no spectrum in Japan and is limited in Europe. "I just got back from Japan, where you can only get an experimental license for UWB, and they seem to have little to no energy" for setting general licensing terms, Heile said.
In Europe, UWB is restricted to the 6- to 10-GHz bands--3 GHz less than in the United States. Developers must also keep UWB transmit power 20 dB lower than in the States, a stricture that could limit bandwidth to 4 Gbits/s. And they must listen for and avoid competing signals. "You basically have to build a small spectrum analyzer into every device," said Heile.
Although there's a handful of standards efforts afoot in high-speed wireless, none specifically addresses the home high-def market. The IEEE 802.15.3c group is taking proposals for 60-GHz radio technology standards, but that work is mainly focused on backbone communications, said Heile.
The WirelessHD group "is looking at a very targeted application" and thus is "likely to be able to move faster" than the IEEE process, said Heile, who commended the group for going its own way.
That said, neither WirelessHD nor a competing, UWB approach called WirelessHDMI, promoted by Analog Devices Inc. and startup Tzero Technologies (see story, page 1), has licensed the core HDMI technology now going into millions of systems a year. "We look forward to working with [both efforts] to make sure they are compatible with HDMI," said Leslie Chard, president of HDMI Licensing LLC.
The oppositionWhat's more, WirelessHD must show a path to multiple chip suppliers with interoperable products. That could take two years from when the group delivers its spec, said Stephen Wood, president of the WiMedia Alliance, which primarily promotes ultrawideband technologies such as wireless USB but has been studying 60-GHz radios.
"UWB is the technology for today," Wood said. "We haven't talked about 60-GHz radios, because they are not mature. We could get consumers all revved up about 60 GHz, but we would be doing them a disservice."
Some of the big consumer companies in the WirelessHD group, Wood said, will roll out camcorders and MP3 players using wireless USB but are not necessarily committed to 60-GHz products. "Most big multinationals place a host of bets and use the resulting technologies that best fit," he said.
In addition to the Tzero/ADI initiative, which will announce OEM partners this week, Bluetooth backers aim to ride UWB to transfer and stream music and video at data rates up to 100 Mbits/s. An initial Bluetooth-over-UWB spec is slated to emerge before June and be finalized with working prototypes available by the end of 2007, about the same time as the WirelessHD effort.
Among wired competitors, HDMI jumped from 5 to 10 Gbits/s with its version 1.3 spec, released in July. OEMs can now deliver products supporting resolutions up to 1,440 progressive, frame rates up to 90 Hz or color depth up to 48 bits, said Chard. The Sony Playstation 3 will be one of the first systems to use HDMI 1.3.
"There is a significant wow factor for deep color especially when you have dynamic lighting, and we've laid a foundation to go beyond 10Gbits/s," he added.
Backers of 1394 have formed another alternative with the High-Definition Audio-Video Network Alliance. Hana aims to extend FireWire into a whole-home network running several hundred meters over various interconnects and carrying generally compressed video, said Jack Chaney, Hana chairman and director of the DMS Labs at Samsung. The Hana approach uses a variety of bridged technologies such as UWB and Ethernet.
Tech hurdlesThe biggest challenge facing WirelessHD may simply be making the technology work as promised. "No one has done anything like this for phased arrays before at the level integration and cost for consumer equipment they are talking about," said Larry Williams, director of business development for Ansoft Corp., which sells high-speed design software. "There will not be many companies able to achieve this in silicon."
"I'm still scratching my head about 60 GHz," said Heile. "It poses some interesting design challenges. But I said the same about 2.4 GHz 15 years ago, and now it's no problem."
One of the toughest nuts to crack will be delivering an adaptive, directional antenna array that can tolerate a living room where people may walk in front of its beam or move the systems around.
"It must automatically figure out the best beam paths between a transmitter and receiver and adaptively change them when the path gets blocked," said Brodersen of SiBeam. And since the arrays are in TVs and DVD players, he said, "you can't require setup to be difficult."
While SiBeam uses vanilla CMOS processes, it requires novel circuit designs and algorithms as well as advanced and often expensive circuit simulation, modeling and testing tools.
"There's very little equipment around to measure this, so we've had to do a lot of work with Agilent on testers," said Brodersen. "The modeling we get from foundries is not appropriate."
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