Linksys PLK300 Powerline Networking Kit Review - End of Ethernet?
No New Wires Networking
Promise of Powerline Networking
You may never have heard about the many promises of powerline networking and how it applies to you and your future in computing. Originally thought to be the answer to connecting rural markets with broadband, powerline networking technology has faltered there and is instead finding a bigger audience with home users.
The idea behind powerline networking is simple: provide connectivity for PCs and other devices over pre-existing electrical powerlines. If you have ever had to run standard Ethernet cable through your house, over floors and around door frames you can quickly see how this networking technology would be a welcome addition to your arsenal.
The Technology at a Glance
Sending data over a powerline work by created a modulated carrier signal over existing copper wiring with different frequencies over signal used for different transmission characteristics. Lower frequencies traditionally can span longer distances and are used for Broadband over Powerlines (BPL) implementations but they tend to have slower speeds measured in single digit Mbps. Higher frequencies allow for more bandwidth but the range on that signal is much smaller and thus this type of technology makes more sense for in-home networking.
Powerline networking technology has progressed quite a bit from its infancy to what we see on store shelves today. While the first in-home iterations of the powerline technology were limited to a few hundred kilobits per second we now have companies like Linksys talking about speeds of 200 Mbps.
In today's market there are two primary consortiums of companies that have competing standards for powerline networking. One of them is HomePlug Powerline Alliance and the other is dubbed the Universal Powerline Alliance. Of the two, the HomePlug group seems to have the most support with companies like Linksys, Cisco, Comcast, Intel, LG and ASUS on the roster. That being said, both of Linksys' primary competitors, DLink and Netgear, are behind the Universal Powerline Alliance. While we are always fans of having a single standard, we have to deal with the split for now.
The Linksys PLK300 kit we are reviewing here uses the technology from the HomePlug Powerline Alliance - the most recent specification ratified for home use is dubbed "HomePlug AV" and was meant to allow for enough bandwidth for HDTV and VoIP transmissions. The theoretical PHY datarate limit on the design was set at 189 Mbps during the December 2005 release but seems to have crept up a bit to hit the magical 200 Mbps that Linksys advertises. One of the benefits of using a standard technology like the HomePlug AV standard is that it allows you to connect other products from other vendors on the network as long as they stick to the same specifications.
There is another standard out from the same group called "Home Plug 1.0 Turbo" that you will find in another new Linksys kit, the PLKT300, that supports datarates up to 85 Mbps. Unfortunately, you CANNOT mix and match these two technologies - you either go for one or the other depending on your usage models.
Potential Powerline Networking Problems
There a few potential problems with powerline-based networking options including its ability to span different power grids for better performance and how that same issue can affect security of your network traffic. The signal that the HomePlug AV standard transmits on the powerlines does not easily jump between power levels and this is part of the reason BPL didn't take off as well as it might - getting the same signal from the carrier, over public lines and through the breaker box into your house could be problematic. In my own testing with this Linksys kit we saw performance differences that were pretty dramatic going from one circuit in the same home to another.
What this also creates an issue for is data security on your network. Since the data is spread over the entirety of your powerline circuitry, and you just need a special device to interpret it, there is a chance that data could be compromised even outside your house if the signal reaches past your local breaker. The HomePlug Powerline Alliance attempts to address this issue with some integrated key distribution techniques and even 128-bit AES encryption are standard.