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HomePNA is here to stay?

Jun 16, 20034 mins

New Version 3.0 of the phone line network spec is multimedia-ready, with quality of service and 100M bit/sec-plus speeds.

New Version 3.0 of the phone line network spec is multimedia-ready, with quality of service and 100M bit/sec-plus speeds

I predicted the death of HomePNA (phone line network technology) some time back, but the technology is still kicking around. In fact, it’s more than kicking around — the Home Phoneline Networking Alliance just released Version 3.0, which appears to be a pretty rocking technology. And the group expects service providers to begin offering Version 3.0 products by fourth quarter — ahead of next-generation wireless and power line offerings.

Version 3.0 has what it takes to stream multimedia: high speed and quality of service  (QoS). According to HomePNA President Richard Nesin, who’s also vice president of marketing for phone line silicon maker Coppergate Communications, Version 3.0 will deliver rated speeds of 128M bit/sec, with an option to go to 240M bit/sec, with very low overhead. Nesin says that means your actual speeds could be as high as 120M bit/sec — great for multiple streams of video or as a whole-home network backbone.

The actual rate you’ll get depends on the size of the various data packets. Audio packets are small, each carrying overhead to slow them down, but they don’t need a lot of bandwidth. Video packets are large, so there are fewer of them, which means less overhead. Yet they require much more bandwidth than audio.

To deliver QoS, Version 3.0 has a synchronous MAC, like FireWire (IEEE 1394) and Gibson Magic, so it guarantees that real-time data transmissions (video and audio) get the bandwidth they need first. Whatever bandwidth remains goes to PC data. Without QoS, a video stream can experience delays and screen freezes, an audio transmission pops and cracks.

Of course, the Wi-Fi Alliance and HomePlug Consortium are each at work on comparable multimedia specifications for their respective wireless and power line technologies. The Wi-Fi Alliance says it expects to complete a draft specification of 802.11e by the fourth quarter, although a Wi-Fi spokesperson admitted that date will probably slip and it’s “very complicated.”

The HomePlug Powerline Alliance plans to have its spec ready by next summer, but you can tack on at least a couple of months for this or that. So you could argue HomePNA has only a short lead on the others. But it’s worth pointing out the technology is finished, and the others are still being developed and subject to unknowns.

Performance-wise, 802.11e doesn’t add more speed, just QoS. So for wireless, you’ll get about half the rated speed on the box (54M bit/sec for 802.11g and 802.11a), although chip vendors are developing on “turbo” versions that should produce much higher speeds. HomePlugAV will deliver 100M bit/sec rated speeds; actual speeds are unknown. Until we try these products we won’t know how important the speed differences are. Timing is what’s really important here.

The reason HomePNA products have disappeared off retail shelves is because they were drowned by Wi-Fi. But HomePNA didn’t die, the Alliance instead signed deals with big service providers — BellSouth, SBC, Verizon and Time Warner Cable. Who knows how much they’re selling? (I’m trying to get numbers.) But Nesin says HomePNA’s broadband partners are eager to get Version 3.0 into their hands, so they can offer their customers a fast, stable technology on which to deliver “triple-play” services (voice, broadcast video and the Web). If customers eat this stuff up, being the first to market with multimedia network technology (and no competition) could mean a lot. HomePNA 3.0 could really gain traction.

But what if broadband customers don’t buy home network equipment and “triple-play” services in any great volume anytime soon? Sure, there’s interest, and we know that eventually they’ll come around when there’s more compelling content to stream around the house. (And, of course, digital rights management and copyright infringement issues have mucked that up.) If consumers don’t start biting, HomePNA will lose its lead to more convenient technologies.

HomePNA’s big flaw is the home’s lack of and poor placement of phone jacks. Nesin says that’s “an old argument,” and that “at least HomePNA can get you from one floor to the next.” He also points out that vendors have introduced Ethernet- and USB-to-HomePNA adapters to help remedy the problem. But I don’t want to buy adapters, and I don’t want to string more cables. Is it me? If you’re a HomePNA user, please write me about how you like it.