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In-home video distribution

Fri, 03/31/2006 - 7:00pm
Jeffrey Krauss, President of Telecommunications and Technology Policy

For me, the big story at the 2006 Consumer Electronics Show was in-home distribution of video. In-home data networks have been around for awhile, but video is more demanding. I saw a number of products, both wired and wireless, that hope to satisfy the consumer's growing demand to watch movies and TV at multiple locations in the home. Some of the buzzwords are HomePlug, MoCA, HomePNA, WiFi, WiMedia, UWB, WHDI and RangeMax. Many of the companies behind these new technologies are small start-ups. My conclusion—the wired technologies are ready for prime time, but wireless is not.

Jeffrey Krauss
One application of home networking is a digital video recorder in one room feeding several digital movies to TV sets in different rooms. Even if a consumer had multiple DVRs, moving a program or movie from one DVR to another would be a problem because home data networking for Internet access just doesn't have the capacity to carry several video streams at once. Even 802.11 devices that have a theoretical maximum of 54 Mbps rarely achieve even half that rate.

At CES there were at least three "wired but no new wires" approaches, using power lines, phone lines and coaxial cable. The power line approach is called HomePlug AV. The original HomePlug 1.0 specification was compatible with cable modem data rates, but products supporting the AV version, using chipsets from Intellon, are now on the market that deliver data rates of 128 Mbps.

The HomePNA technology has been around for a while. Version 3.0 has recently been adopted as a standard by ITU-T (as Recommendation G.9954) and supports data rates up to 240 Mbps. Scientific-Atlanta (now part of Cisco Systems) recently announced set-tops with HomePNA 3.0 technology built in. This networking technology was developed by CopperGate Communications.

MoCA stands for the Multimedia over Coax Alliance, an alliance of cable operators, set-top manufacturers and consumer electronics companies. The technology was developed by Entropic Communications. This uses the existing coaxial cables already deployed in the home, and uses frequencies above the highest cable TV frequencies for home networking. The cables and splitters work just fine up to 1200 MHz or higher, and data rates of 80 to 120 Mbps were achieved in trials.

There were also wireless approaches at CES, including both smart antenna techniques and smart modulation techniques applied to WiFi, plus two different flavors of UltraWideBand (UWB).

Netgear already has an 802.11 product on the market that it calls RangeMax, which uses the smart antenna technology from Ruckus Wireless. The Ruckus antenna is actually an array of six antennas that can form directional beams, coupled with signal processing software that determines the best signal path. These antennas aren't dishes—they are patches of conductive material laid down on the printed circuit board, so you'd never know they are there. This antenna technology can be used with any flavor of WiFi, including the next-gen 802.11n that incorporates multiple transmitters and receivers in a single device to bond several WiFi channels together. The smart antenna minimizes the fades and dropouts inherent in wireless communications, and guarantees a better quality of service. It does this by finding the best directional path between transmitter and receiver, and it adjusts that path as someone walks through the house.

A small Israeli startup, Amimon, has developed a proprietary modulation and signal processing method that uses 802.11a frequencies at 5 GHz, but achieves a data rate of 1.5 Gbps in a 20 MHz wide 802.11a channel. They call it the Wireless High Definition Interface (WHDI). While all of the other home networking technologies carry compressed (MPEG-2 or MPEG-4) video around the house at a data rate up to 200–300 Mbps, this system is designed to carry uncompressed HDMI video around the house. Transmission errors—always present in wireless links—are imperceptible because of their unique signal processing, which provides more error protection for the more critical signal components.

And finally, there is UWB: Two factions, with two incompatible designs, neither one able to achieve the majority needed in an IEEE technical standards vote, and the two sides unwilling to reach a business compromise. So we have the Freescale version of UWB, and we have the WiMedia version of UWB. Freescale is a chipmaker, and used to be the semiconductor division of Motorola before it was spun off. One familiar consumer products name that is using the Freescale UWB chip is Belkin. Belkin has a USB hub that communicates over a UWB wireless link to a dongle plugged into a nearby laptop; distances are limited to a few dozen feet. Not exactly ideal for home networking of video. The WiMedia folks, a large alliance of companies led by Intel and Texas Instruments, don't have any actual products yet. But their technology is part of the Wireless USB standard.

The three wired technologies are all being deployed in cable and satellite set-top boxes. The wireless folks aren't there yet. Their challenge is to convince set-top box manufacturers to build their technology into the boxes, the way the wired proponents have done. We'll see whether they can catch up.

Have a comment? Contact Jeff via e-mail at: jkrauss@krauss.ws

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