Depending on your outlook, home-networking technology is either a shining example of success or a dismal failure. A number of networking options shine when the application is shared Internet access, but every "no-new-wires" technology fails when the mandate calls for carrying multiple HD video streams simultaneously.

The no-new-wires requirement is the primary delineation between home networking and enterprise networking. Companies will spend money to wire offices and boost productivity, but only tech enthusiasts will retrofit a home with Category-5/6 twisted-pair cable for high signal integrity. To achieve mainstream success, home networks--even those that carry rich video streams--must be wireless in nature or operate over existing phone lines, coax cable, or power lines.

Wi-Fi in all of the IEEE 802.11 flavors has broadly penetrated the home although enterprise usage was the application that drove prices down to home-friendly levels. Unfortunately, the newest 802.11n flavor is a troubled technology. The long-debated standard resulted in fragmentation, and products are falling far short of range and speed specs. There's little reason to believe that Wi-Fi is going to deliver whole-house HDTV.

Wireless USB based on ultrawideband (UWB) technology is a bigger failure. It doesn't appear that Wireless USB will carry HD video even within a room, although it may find success in PC peripherals.

Today, consumer electronics vendors are looking at proprietary in-room wireless links, but these solutions also pose challenges. For example, Amimon Inc. has limited support for its yet unproven 5-GHz technology. Even if it works, it won't carry multiple streams and should be redirected at compressed content. And the 60-GHz research is too immature to judge.

Why are we talking in-room links? There is no single perfect home-network technology that can serve legacy data and HD-streaming applications. Instead, a backbone of some type will connect islands of devices that might be served by a technology with limited range.

For the backbone, coax-based networks look viable but may not reach every island in a home. Power-line options would be ideal because power plugs are found in every room. But alas, power-line technology falls short of HD bandwidth requirements, and phone-line options look like a long shot. Ethernet and Category-5/6 cable remain by far the best choice to serve whole house video. Let's watch what happens in 2009.