A wireless boost for video at home

Your PC may soon be beaming video around the house. A hot topic at CES is likely to be which tech works best.

Marguerite Reardon
Marguerite Reardon Former senior reporter
Marguerite Reardon started as a CNET News reporter in 2004, covering cellphone services, broadband, citywide Wi-Fi, the Net neutrality debate and the consolidation of the phone companies.
5 min read
Everyone from Apple Computer to Microsoft is promising products this year that will stream photos, movies and music from PCs to TVs and other screens around the house. How is all that content going to make it from your living room to other devices around the house?

The answer is likely to be: through a wireless connection. Some technology groups are promoting the use of existing cable TV infrastructure or electrical wiring throughout the home to distribute media. Many pundits, however, say wireless could be the cheapest and most convenient option for distributing media throughout the home.

"The cable or satellite TV hook up is never where you want it," said Craig Mathias, an analyst at Farpoint Group. "And running new wires throughout the house is expensive and a mess. Wireless lets you move the TV or use another device to watch something anywhere in your house."

Truth be told, wireless media streaming has had its problems. Companies such as Linksys, Dell and Sony have released products, and sales have stunk. Still, experts say new wireless technologies could make in-home wireless distribution more compelling.

These technologies are likely to be hot topics of discussion this week at the Consumer Electronics Show in Las Vegas, where several companies will be touting multiroom DVRs, media centers and adapters, and at MacWorld in San Francisco, where Apple will likely give more details about which wireless technology it plans to use with its iTV product.

Technologies likely to get the most buzz will be Wi-Fi and maybe even Wimax along with shorter range wireless technologies, such as ultra-wideband (UWB) and the new Wireless HD technology.

Most of the chatter around Wi-Fi will come from companies showing off products based on the emerging standard 802.11n. While the IEEE hasn't yet ratified the standard, the Wi-Fi Alliance is expected to certify equipment as pre-standard 802.11n later this year. Experts don't expect the standard, which has been batted around by different companies in the industry for more than a year, to change much from what the Wi-Fi Alliance certifies and what the IEEE ratifies in late 2007 or early 2008.

Many vendors have been shipping routers that comply with the first draft of the 802.11n standard for more than a year. Some of these players will be showing off their equipment at CES. The new Wi-Fi standard is being groomed for video delivery because it delivers higher data rates than previous versions of Wi-Fi did, boosting throughput to as much as 540 megabits per second at its peak. This is 10 times the peak data rate of 802.11g technology. Realistic sustained speeds are likely to be much less than this, but 802.11n still transmits much faster and farther than the current generation of Wi-Fi.

And because 802.11n uses MIMO (multiple-in, multiple-out) technology, it can reach greater distances--up to 150 feet indoors. When implemented correctly, it can also penetrate through several walls, providing coverage throughout an entire home, said Greg Raleigh, vice president of wireless connectivity for Qualcomm and formerly the president of MIMO chipmaker Airgo, which was recently acquired by Qualcomm.

"When 802.11n is deployed well, it is a no-brainer for delivery of video," he said. "You don't have to worry about any old cable plant or circuit breakers that may impact transmission."

Companies, such as the start-up Ruckus, have developed technologies that work with Wi-Fi to improve reliability. Because Wi-Fi uses an unlicensed spectrum, it can suffer from interference from other household wireless devices, such as wireless phones and garage door openers. Ruckus has already developed a "smart Wi-Fi subsystem" for 802.11g signals, and it will likely introduce one for 802.11n as well.

Other companies have also tinkered with Wi-Fi to improve performance and reliability. Neosonik, a start-up from Northern California, has come up with a proprietary spin on 802.11a for a wireless home stereo system. Quartics also has devised a Wi-Fi chip for this task.

Some companies, such as Radiospire Networks, have suggested using Wimax to transmit video throughout the home. Intel and Motorola have been working to develop Wimax chipsets for PCs and other consumer electronics. But for the most part, the technology has been seen as a wide-area broadband technology that could replace or augment cellular or citywide Wi-Fi services. Nationwide cell-phone carrier Sprint Nextel has already said it plans to use Wimax to deliver its next generation wireless service over 2.5GHz spectrum.

While 802.11n Wi-Fi greatly improves throughput for Wi-Fi signals, the technology is not fast enough to support high-definition streams without compressing the video signals. By contrast, other wireless technologies are emerging that provide very high bandwidth, but those transmissions are over much shorter distances.

For the last couple of years, chipmakers have touted UWB technology as the high-speed, short-range, low-power wireless technology that would do away with cables. But for more than a year, it has languished without a firm standard. Even so, the technology seems to be getting a bit of a revival as the WiMedia Alliance starts certifying some products. Belkin has announced a wireless USB Hub that offers transfer speeds up to 480Mbps at more than 30 feet. The European Union has given the technology the green light, and SK Telecom in Korea has stated plans to work with chip vendors to embed UWB in cell phones.

In general, the UWB technology is capable of offering data transmission speeds ranging from 100 megabits per second to more than 2 gigabits per second. But unlike Wi-Fi, it is limited in distance, only transmitting between 10 feet and 30 feet. For this reason, Wi-Fi supporters say the UWB technology will never catch on for distributing video throughout the home.

"Ultrawideband has no hope in distributing video in the home because 10 feet is just too short a distance to be worthwhile," said Qualcomm's Raleigh. "That barely gets you out of one room, and it doesn't allow you to transmit through walls. If you want to transmit video from a central DVR to another DVR in another room, it just won't work."

But some experts like Farpoint's Mathias believe the distance limitations may not be such a problem as repeaters could be used to boost the signal over greater distances. He said it could be much more important to transmit signals uncompressed so that users don't have to sacrifice picture quality.

Other emerging short-range wireless technologies could prove ideal for transmitting uncompressed HD video. Late last year, Sony, Panasonic, Samsung, Toshiba, NEC and LG Electronics announced they were working on a technology called WirelessHD , which could transmit high-definition video and audio between a consumer's entertainment devices by using the unlicensed 60GHz spectrum. The final specification is expected by spring 2007, and products could ship in 2008, the companies said.

Each of these technologies is evolving, and each has positive and negative attributes, which makes Mathias hesitant to pick a single winner. By next year's CES, the picture should be much clearer.

"None of these technologies is perfect," he said. "But eventually the market will settle on one or two."