The Technology

Like HomePNA, power-line networking is based on the concept of "no new wires." The convenience is even more obvious in this case because while not every room has a phone jack, you will always have an electrical outlet near a computer. In power-line networking, you connect your computers to one another through the same outlet.

Because it requires no new wiring, and the network adds no cost to your electric bill, power-line networking is the cheapest method of connecting computers in different rooms.

Pros and Cons
There are two competing power-line technologies. The original technology is called Passport, by a company named Intelogis. A new technology called PowerPacket, developed by Intellon, has been chosen by the HomePlug Alliance as the standard for power-line networking.

Here are the advantages of a power-line network:

  • It's inexpensive. (This author bought a complete Intelogis' PassPort kit to connect two computers for $50.)
  • It uses existing electrical wiring.
  • Every room of a typical house has several electrical outlets.
  • It's easy to install.
  • A printer, or any other device that doesn't need to be directly connected to a computer, doesn't have to be physically near any of the computers in the network.
  • It doesn't require that a card be installed in the computer (although there are companies working on PCI-based systems).
The new PowerPacket technology provides a couple of other advantages as well. It is fast, rated at 14 megabits per second (Mbps). This speed allows for new applications, such as audio and video streaming, to be available throughout the house.

There are some disadvantages to connecting through power-lines when using the older Intelogis technology:

  • The connection is rather slow -- 50 Kbps to 350 Kbps.
  • The performance can be impacted by home power usage.
  • It can limit the features of your printer.
  • It only works with Windows-based computers.
  • It uses large wall devices to access an electrical outlet.
  • It can only use 110-V standard lines.
  • It requires that all data be encrypted for a secure network.
  • Older wiring can affect performance.


Photo courtesy Intellon
New power-line networking products are based on Intellon's PowerPacket technology.
According to Intellon, PowerPacket technology eliminates many of these concerns, citing the following advantages:
  • It is very fast, rated at 14 Mbps.
  • It "avoids" disruptions in the power-line, maintaining the network's connections and speeds.
  • It does not limit the features of your printer.
  • It can be compatible with other operating systems (depending on driver availability).
  • It may have the necessary circuitry embedded within the device, necessitating only a standard power cord to access an outlet.
  • It works independent of line voltage and frequency of current.
  • It includes encryption.
  • In tests, it showed no signal degradation due to older wiring.

Now let's find out how each of these technologies works.