
The CEBus standard (also known as EIA-600) offers networking support over power lines and other media. Alas, after years of work, the standard is still endlessly debated by a gargantuan group of manufacturers, with no data-networking products announced as of this writing. It doesn't deliver the necessary bandwidth, and has a very weak data channel--only 10 Kbps in its first standard form.
That's not to say there are no power-line-based products at all. Proprietary parallel-port based networking products from Intelogis (www.intelogis.com) are sitting on the shelves at your favorite retail outlet right now. (Just don't ask the employees how they work; it seems to me that most computer stores combat theft by forbidding employees to learn what products actually do. Some staffers probably just take items for the colorful boxes and dump the contents as soon as they get them home.) Intelogis Passport is easy to set up, but at only 350 Kbps it's barely adequate for printer sharing, let alone data networking.
Higher-speed power-line technology has also been licensed to Microsoft from Intellon Corp. (www.intellon.com), in the form of its spread-spectrum carrier technology, which operates at a minimal megabit per second, so it's not worth getting too excited about. The Intellon folks claim 10 Mbps is achievable, but I'm skeptical that they'll be able to overcome power-line noise and deliver at a reasonable cost. It also offers no native security, no QoS, and it's proprietary.
One Ringy Dingy Since power-line networks come up short, perhaps home telephone wiring can provide a better answer. Most rooms have at least one phone jack, and voice uses only a small part of the available spectrum that even low-grade phone wire can support. You can run ISDN or Universal ADSL/G.Lite over these wires and still leave a decent channel for a LAN. Best of all, a market standard for data networking over phone lines is gaining momentum.
The Home PhoneLine Networking Alliance (HomePNA, www.homepna.org) has adopted Tut Systems' HomeRUN technology, moving slightly modified 802.3 MAC frames over phone-grade, randomly installed wire without disrupting existing phone service. It's been licensed to Compaq for an unnamed future product, and Intel has incorporated it into a 1/10/100 Ethernet chip.
Based on cost and distance, HomeRUN may well be a minor-league hit. It requires no hub equipment, and devices can be up to 500 feet apart. Need a telephone from the same jack that provides data? Spend a buck at Radio Shack for a common phone line splitter. Hook several PCs together with a multiport telephone line splitter, and it's the world's least expensive Ethernet hub.
Now the bad news: The HomePNA spec is stuck at 1 Mbps today, and can leak low-voltage signals out to the street--requiring encryption at higher layers, which increases delay, consumes bandwidth and eats endpoint resources. But there may yet be hope: A 10-Mbps standard appears to be around the corner, probably based on Epigram's Home Ethernet technology (www.epigram.com). Epigram claims it ultimately will be able to run at 100 Mbps over a phone line, and will offer QoS too. The really bad news: It's likely that new hardware will be required when the new standard appears, so existing HomePNA gear won't be able to achieve the higher speed. My advice: Wait for the second-generation products.
No Strings Attached Since power-line and phone-line networking aren't ready, the best approach may be to forget wiring altogether. I've long been a happy user of BreezeCOM's 802.11-based wireless LAN products, which offer double the usable bandwidth of anything I've discussed so far. I've used the devices all over my office and home, and never had any trouble with them. I've been known to work in the backyard (when I'm doing research on how difficult LCD screens are to read in the sun). It's standards-based, it's easy to install, it supports connections to a standard Ethernet NIC and it works today. I don't even have to crack the PC case to go wireless.
Yet 802.11-based wireless LANs are many times more expensive than the alternatives. They don't support the very high-speed multimedia applications that are the true Holy Grail of home networking. To reduce costs, a "technically relaxed" version of 802.11 is being adopted by the HomeRF Working Group (www.homeRF.org) in its SWAP (Shared Wireless Access Protocol) specification. SWAP has multimedia aspirations--a voice channel, compression and even encryption--but paltry bandwidth. When SWAP-based products hit the market in late 1999, they will offer only 1 to 2 Mbps for data networking.
Just as with power-line networking, low-cost products are available today that support low-speed wireless networks across short distances. Forage around a computer store and you'll find proprietary products from WebGEAR and Diamond Multimedia that operate at 500 Kbps and 1 Mbps, respectively, for around $80 per PC.
So, are we doomed to run new wire? Will high-bandwidth home networking mean fishing wires through fiberglass-filled walls and drilling holes in baseboards? Perhaps not, if you can stomach a proprietary solution. ShareWave Digital Wireless (www.sharewave. com) may blow the doors off all the other options. ShareWave's Digital Radios start with a 4-Mbps channel and incorporate wavelet-based compression technology that they claim delivers video throughput up to 120 Mbps, over distances of up to 150 feet. SDW has authentication and encryption. It has flow control, forward error correction and traffic prioritization, and it's expected to cost less than current wireless LANs. Look for products that are scheduled to emerge in early 1999 from at least one major consumer equipment manufacturer.
Send your comments on this column to David Willis at dwillis@nwc.com.
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