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Is Your Digital Home Future Proof? — Part 2
 The second article about the promise — and challenge — of building and selling “digital homes.”
In this article on making your new digital home projects “future proof,” we will discuss the challenges of networking, your best choices for HDTV connectivity, the latest trends in wireless and what to do if you’re technologically challenged.
Speeds and Feeds: Cable and Bandwidth Considerations
One of the technical issues that stands in the way of the fully networked vision for home living is Quality of Service (QoS). The technologies you use — and how you install them — affect QoS for each technology and the overall QoS of the home.
HDTV: When a high-definition television (HDTV) signal passes through coax, the builder should only worry about bending the radius of the cable too much and connectors. Coax degrades the signal if bent too sharply.
However, when an HDTV signal passes through ethernet, bandwidth comes into play and can affect video quality and QoS.
HDTV signals can take 19 megabits of bandwidth. But many of today’s networks are 100baseT (100 megabits/second) running through Cat-5 cable.
So what’s the problem?
Quite possibly, overcrowding. Video and audio are isochronous — the data must flow continuously. Ethernet was designed for synchronous data steams. Synchronous means that signals and data will get to where they’re supposed to be — but not necessarily on time.
Consumers are demanding more and more Internet bandwidth. Some, in fact, will soon get 20 or even as much as 100 megabits of bandwidth from their cable or telephone company.
So, with everything sharing 100 megabits of bandwidth, there is a chance the video will freeze — in other words, poor video QoS.
The Digital Living Network Alliance (www.dlna.org) — an alliance of technology companies that are working to establish an interoperable network of personal computers, consumer electronics (CE) and mobile devices in the home that home owners can enjoy and builders can deliver — specifies some protocols to help manage bandwidth issues. But managing bandwidth can only achieve so much QoS.
Wise builders should consider incorporating the next generation of ethernet — 1000baseT which provides 1 gigabyte of raw bandwidth. To be truly effective, 1000baseT should run over a tighter tolerance cable called Cat-5e or Cat-6.
Some STB (set top box) makers can send video room-to-room over existing coax instead of Cat-5 or 6, so there is no need for new cables. Scientific Atlanta and Motorola both offer a STB with built-in DVR that can send recorded video to another STB, but they use different technical approaches. That means less flexibility for the builder because both ends of the technology must come from the same vendor.
Going Wireless: Promise and Limitations
What about wireless? Unfortunately for wireless, today’s systems do not have the bandwidth to handle HDTV video streams. But a few things are about to change.
WiFi: One is a pending standard called IEEE 802.11n. This form of WiFi offers a more robust link with about twice the bandwidth (effectively about 100 megabits/second).
This type of WiFi could be used for some HDTV situations, but the most reliable link will still be wires. WiFi, in general, will remain more useful for situations that don’t need isochronous data links — such as networking PCs.
Ultra-Wideband: Another pending technology is ultra-wideband (UWB). UWB has a reliably high bandwidth link, but for very short distances (say 30 feet).
Some manufacturers are planning on using UWB to send HDTV video to wall-mounted flat screen TVs. UWB solves many problems because normal digital video cables for HDTV are bulky, particularly for longer cable lengths.
ZigBee™: A third form of wireless is called ZigBee™ (www.zigbee.org) — a low-power, low-cost, but also low-bandwidth, form of wireless. Companies are building ZigBee™ into light switches, thermostats, drapery controllers, alarms and just about everything else imaginable.
For home control features, expect to see more of this form of wireless in the near future.
Who’s Your IT Manager?
Another issue slowing down the digital home is complexity. You practically need to be an IT manager to know how to set up some of these products.
A company called Dedicated Devices, for example, has a low-cost product that distributes music, photos and some video (though not HDTV) over ethernet. The company sells almost exclusively to new home developments.
Most people today turn to professional installers. So do many of the companies that make digital home products. Most of these companies exhibit at a show called CEDIA (Custom Electronics Design and Installation Association — www.cedia.org). Talking to these types of companies can give you a reasonable picture of today’s situation and where the industry is going.
DLNA is trying to make everything plug-and-play, but much work remains. Eventually the digital home will be more affordable and easier to set up. Two-way digital cable-ready products (today’s are just one-way), DLNA 2.0 products (2.0 is being worked on), and other changes will tempt more consumers to give it a try.
When this happens, be prepared for another issue:
Remember when there used to be only one power plug outlet per room? — Will just one ethernet jack per room be enough?
Gary Sasaki is the president of Silicon Valley, Calif.-based DIGDIA, which provides strategic analysis and consulting of digital media industries. For more information, visit www.digdia.com for a glossary of more than 1,000 digital home terms, industry reports and links to dozens of related organizations and publications.
This article excerpted from the fall issue of Building Women, published by NAHB's Women's Council.
To read the first article in this series, which appeared Feb. 27 in Nation's Building News, click here.
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