Power-line technology uses a building's existing electrical system as a conduit for electronic data. The wall outlets serve as connection points, or nodes, on the network. Transferring data over the electrical network doesn't interfere with your electricity because data is transmitted at a higher frequency than electricity. Power-line systems involve connecting your router into the master adapter via a standard Ethernet cable and plugging that adapter into a wall outlet. Network clients are plugged in to additional adapters, which are also plugged in to wall outlets; basically, anywhere you have a wall outlet, you should be able to connect to your network via an adapter. Some power-line adapters, such as Netgear's WGXB102, mix Ethernet connections with wireless capability by rolling a wireless access point in to the wall-plugged unit, letting you extend the reach of your wireless network anywhere you have an electrical outlet. Panasonic's adapters don't incorporate wireless technology but still allow you to easily extend your network.
Panasonic's Ethernet adapters are about the size and shape of a bulky point-and-shoot camera. The only components are a power port, an Ethernet jack, a master/terminal switch, and a setup button. Unlike the petite Netgear XE102 Powerline Adapter, the Panasonic HD-PLC uses a power cable to connect to the wall outlet. It won't block an additional outlet, but this does mean you'll be faced with yet another cord.
Setting up Panasonic's HD-PLC Ethernet adapters couldn't be easier. The best way is to begin with the starter kit, which comes with two preconfigured adapters, because you'll need at least two to create a network. Simply plug in the Master adapter (so labeled) to a wall outlet near your router. Then plug in the second Terminal adapter anywhere you want to have access to your network. At this point, the three LEDs should light in different combinations to indicate whether the adapters are set up correctly (the included installation guide outlines the meanings of the lights). If all is set up correctly, the final step is simply to connect your equipment, such as PCs, networkable printers, and NAS hard drives, to the adapters via Ethernet cable. Unfortunately, the adapters don't come with Ethernet cables, a shortcoming we can't forgive, as Netgear's XE102 adapters come with a six-foot cable and even wireless routers come with an Ethernet cable for connecting the router to a modem.
Your router should be connected to the Master adapter. Each adapter has only one Ethernet port, but you can connect it to a hub or a switch (from any networking vendor) to network multiple devices using a single adapter (Panasonic recommends a maximum of eight devices per adapter and a max of 16 adapters per network). If you need more than the two adapters that come in the starter kit, which costs about $200, you can purchase Panasonic HD-PLC adapters individually for about $130. Because these aren't preconfigured to the Master adapter, you'll have to configure them by plugging them into the same wall outlet as the Master, pressing the setup buttons on both units, and waiting for the indicator lights to show that the new adapter has been successfully set up. At that point, you can move the new adapter to any other point in the house. We were set up and on the Internet in mere minutes. If you have an adapter in each room of the house, the cost can add up quickly to hundreds of dollars. With a wireless network, you can often add clients to the network using a $50 wireless USB adapter. Of course, as mentioned above, you can use one adapter to network up to eight clients, so that helps keep the cost down. Unfortunately, it does nothing for cable clutter.