Q: I want to use powerline networking to link my computers. But how do I avoid interference from my appliances that use the powerlines? Also, I live in an apartment. Will other people in my building be able to tap into my network?
A: Powerline networking uses adapters that allow networked devices (PCs, gaming consoles, etc.) to plug directly into wall outlets and send data over your home's electrical wiring. But powerline networking operates on a different frequency from AC current. (Electricity in the United States runs at 60 Hz, whereas networking data travels in the megahertz range.) And, powerline networking operates at lower voltages than the 110-volt AC waveform.
That's not to say that interference can't occur. "A hair dryer or vacuum cleaner may temporarily decrease throughput," cautions Kartik Gada, Netgear's powerline networking product manager. It shouldn't knock the powerline networking offline, though, just temporarily slow it down. Most appliances won't affect powerline networking, especially since nearly all powerline devices now include frequency-hopping technologies to mitigate interference.
Depending on how your house or apartment is wired, neighbors could theoretically plug a compatible powerline networking device into their outlet and be on your network. That's why all powerline networking gear either requires pairing via physical buttons on each device, or includes an optional encryption scheme, similar to that used with Wi-Fi, that will prevent anyone from jumping on your network -- even if you're on the same circuit.
But not all powerline devices work together. Most of the older, slower devices use the HomePlug standard. But the newer, faster 200-megabit-per-second (Mbps) varieties -- fast enough to stream HDTV -- are split into two camps: gear based on technology from the Spanish company DS2 (available primarily from Netgear in the States) and the HomePlug AV standard from the likes of Linksys and Zyxel.