ZyXEL PL-100 Powerline Ethernet adaptor

Review You can't beat a wireless network for true ad hoc connectivity. But like so many things in life, there's a catch - several, in fact. Depending on the construction of the building you inhabit, there may be areas where you can't get a signal. If, like me, you live in a neighbourhood stuffed with 802.11b and 802.11g networks, you can find them interfering with each other, limiting the available bandwidth. And then you've still got to ensure your WLAN's as safe as it can be from snoopers.

One alternative is to lay down wires, but that's costly if you do it right and a leg-break hazard if you don't. However, Taiwanese communications kit make ZyXEL has another recommendation: use the cables you've already got - your power lines...

Running communications signals over mains power cabling is nothing new, of course. Intercoms have been doing this for years, but while data applications have followed voice, powerline networking has never really taken off.

The development of the HomePlug 1.0 standard has helped, and powerline networking has found a place in many a US home. In Europe, however, the preference has been for wireless networking, thanks to a plethora of cheap access points and add-in cards, and the ease with which they can be set up.

ZyXEL's pitch is that powerline is faster, pushing a maximum throughput of 85Mbps to 802.11g Wi-Fi's 54Mbps. Powerline is more secure, too, since it's inherently harder to tap into a powerline network, though ZyXEL's latest powerline box, the PL-100, encrypts everything using DES with 56-bit keys.

Each PL-100 is a small, silvery, modem-sized box you can sit on your desk, the floor or even mount on the wall next to the mains socket - though watch where you're drilling, OK? I'd have liked to have seen a wall-mount bracket, or at the very least a screw-hole template, in the box for this, but a professional installer or a skilled DIYer should have no trouble. The box has just two ports: an Ethernet port to connect the unit to a PC, printer, hub or switch, and the power cable.

As soon as you connect the PL-100 to the mains it starts looking for compatible devices - it'll work with an HomePlug 1.0-compliant device, says ZyXEL - and is ready to start exchanging data when it finds one.