"It's been slow taking off in the US," noted Eric Deming, product marketing manager at Cisco-Linksys, a HomePlug vendor and a division of Cisco Systems. "As with HomePlug 1.0 and Turbo, initial acceptance has been better in Europe, where using wireless is problematic because of the brick and mortar used in home construction. It's also been a little expensive -- it costs US$179 for two, where US$149 will get you wireless card and a wireless adapter. It's also a little bit nonintuitive -- buyers may not understand that they need two, one for each end. That's why we sell them in kits of two."

Deming said that a HomePlug AV system might, in an ideal environment, achieve 86Mbit/sec. to 90Mbit/sec., but that extensive testing showed that 35Mbit/sec. is a realistic expectation. However, he noted that 35Mbit/sec. is sufficient for high-definition video, which usually takes 20Mbit/sec. Aluminum house wiring (used three decades ago), halogen lights, long wiring runs and electric motors can also degrade a signal, he noted.

"The biggest problem is consumer education," added Lesley Kirchman, marketing director at ActionTec Electronics. "Many people don't understand how easy it is. Words like 'easy' and 'simple' are overused, and people tend to be jaded. And I think that a lot of people are afraid of networking."

UPA standard

UPA backers tout the fact that UPA got to the market first with 200Mbit/sec., as the first UPA adapters for home use began shipping in January 2005, and volume production began in April 2005, explained Brian Donnelly, president of the UPA Marketing Working Groupand vice president at Corinex Communications Corp. in Vancouver, British Columbia.

"There have been about a dozen firmware upgrades since then, and it's become pretty bulletproof," he said. The chief difference cited between UPA and the other two technologies is a feature that allows an adapter to be placed in a long wire run to boost the signal between one end and the other. Thirty-three adapters can be used in a home network, but some configurations are open-ended, he added. For encryption they use 168-bit DES. Throughput can reach 95Mbit/sec., he said.

Initially, most sales were in Europe, but retail acceptance ballooned last year in North American, with sales rising 800%, he said. He expects that 3.5 million devices will have shipped by year's end.

There are about 15 vendors shipping UPA products, one of which is Netgear. "We chose UPA because of the quality and because UPA was there first. We were on the market a good six to eight months before HomePlug came out," said Jamie Ching, Netgear's powerline product manager. But Netgear also sells HomePlug units, he noted.

"Ninety percent of the time, you can just plug and play," Ching said. "The other 10 percent of the time, the house may have older wiring, or it may have added wiring that doesn't have good connectivity with the older wiring. But the technology is robust enough for most situations." Most appliances do not interfere, he added.

Panasonic HD-PLC

The third technology is Panasonic Corporation of North America's HD-PLC, based on proprietary technology including Panasonic chips, explained Mike Timar, product manager at Panasonic USA in Secaucus, N.J.

The theoretical speed of the units is 190Mbit/sec., and Timar said that users could expect a throughput of 40Mbit/sec. to 45Mbit/sec. for file transfers and up to 80Mbit/sec. for streaming, where lost bits are immaterial. He noted that, by comparison, DVDs output at 6Mbit/sec., and an uncompressed Blu Ray disc uses 33Mbit/sec.

One unit in an HD-PLC network is designated the master by setting a switch. The units use 128-bit AES encryption, and they can be set to use a new random key, without software, by pressing buttons on the master unit, he added. Sixteen adapters can take part in one network.

"We are looking to the time when you can plug your plasma TV into a power outlet, and no other connections are needed," Timar said. "In the meantime, we have come out with these adapters, and they are selling pretty well. But I think that the customers don't appreciate the benefits of higher speeds and security and robustness, since they have nothing to compare it with."