Powerline Networking: Not for Everyone?

The choices for home networking have grown wider (and a bit more confusing) with the introduction of the first HomePlug Powerline 1.0–compliant network adapters and bridges.

Powerline networking promises throughput competitive with other wired home-networking technologies (especially HomePNA Phoneline 2.0, which uses your home's existing phone lines to transmit signals) and simple installation. All you have to do is plug an adapter into any AC power outlet in your home to connect to your network.

In typical home settings, Powerline delivers on its promises. We tested four of the first products on the market (two from Linksys and one apiece from Netgear and Phonex). Installation is indeed simple. On our throughput tests, Powerline products were a bit slower than the sample Phoneline adapters we tested for comparison, but the difference wouldn't be noticeable by most people for typical home-network tasks (such as sharing files, a printer, or a fast Internet connection).

But Powerline technology does have limitations that might rule it out for some users. If you have a high concentration of computer and other electronic equipment, for example, throughput is likely to suffer. We also found that one of the outlets in our basement home office—the last one on the circuit, with many other electronic devices between it and the circuit box—was not able to establish a Powerline connection with most of our upstairs locations, although it worked (albeit slowly) with locations in our home office area

Of greater concern, at least in the near term, are the relatively high prices of Powerline networking adapters. True, Powerline is a better alternative for most homeowners than drilling into walls to run Ethernet cable, but with current prices ranging from $130 to $150, these products are roughly twice the cost of Phoneline solutions. And they are even costlier than 802.11b networking kits, which typically deliver much better speed, as well as wireless convenience (a big plus if a laptop PC figures into your mix).

According to the HomePlug Powerline Alliance, an industry consortium (www.homeplug.org), there is a case to be made for Powerline technology. For starters, you don't have to run new wires to set up your network. Also, networking could be built into a range of productivity, security, and entertainment devices for the home; if a device needs to be plugged in, it could be part of your network. So, for instance, a Powerline-aware stereo receiver could receive and play MP3 files stored on your PC.

In addition, Powerline devices are rate-adaptive, dropping to lower rates if interference on the power line from other sources is high. Earlier ventures in networking via home power lines didn't meet with much acceptance, but HomePlug 1.0, which was field-tested in 500 homes last year, was found to be effective on power outlets throughout most homes.

The theoretical maximum data-throughput rate of Powerline networks is 14 Mbps, with an average actual rate of about 6 Mbps. That's competitive with HomePNA, 802.11b Wi-Fi, and HomeRF 2.0 wireless networks. Powerline's proponents also claim that the technology is easier to understand than phone-line networking, avoids the "dead spots" of wireless networking (some places in the home where you cannot get a signal), and is cheaper than wired Ethernet.

The standard Powerline adapter is about the size of an external modem. The adapter typically plugs into a power outlet in your home and then into an Ethernet or USB port on your desktop or notebook PC. Note that you should plug a Powerline adapter directly into an outlet on your wall—not into a surge protector or UPS—because the adapters work via shared bandwidth in the AC power circuitry. Devices that condition or filter power can interfere with Powerline networking, and the adapters have their own internal surge protectors.

In some cases (as with the Netgear and Phonex adapters we tested), you don't even need to install any software on your PC to connect with a network. Assuming your PC has already been configured with TCP/IP and with either fixed IP settings or for DHCP and automatic IP assignments, you can just connect the adapter to your PC, plug it into a power outlet, start the PC, and you'll be ready.